I18N: change default on smtp transport, to downconvert-when-needed

[exim.git] / doc / doc-txt / ChangeLog

This document describes *changes* to previous versions, that might
affect Exim's operation, with an unchanged configuration file.  For new
options, and new features, see the NewStuff file next to this ChangeLog.


Exim version 4.94
-----------------

JH/01 Avoid costly startup code when not strictly needed.  This reduces time
      for some exim process initialisations.  It does mean that the logging
      of TLS configuration problems is only done for the daemon startup.

JH/02 Early-pipelining support code is now included unless disabled in Makefile.

JH/03 DKIM verification defaults no long accept sha1 hashes, to conform to
      RFC 8301.  They can still be enabled, using the dkim_verify_hashes main
      option.

JH/04 Support CHUNKING from an smtp transport using a transport_filter, when
      DKIM signing is being done.  Previously a transport_filter would always
      disable CHUNKING, falling back to traditional DATA.

JH/05 Regard command-line receipients as tainted.

JH/06 Bug 340: Remove the daemon pid file on exit, whe due to SIGTERM.

JH/07 Bug 2489: Fix crash in the "pam" expansion condition.  It seems that the
      PAM library frees one of the arguments given to it, despite the
      documentation.  Therefore a plain malloc must be used.

JH/08 Bug 2491: Use tainted buffers for the transport smtp context.  Previously
      on-stack buffers were used, resulting in a taint trap when DSN information
      copied from a received message was written into the buffer.

JH/09 Bug 2493: Harden ARC verify against Outlook, whick has been seen to mix
      the ordering of its ARC headers.  This caused a crash.

JH/10 Bug 2492: Use tainted memory for retry record when needed.  Previously when
      a new record was being constructed with information from the peer, a trap
      was taken.

JH/11 Bug 2494: Unset the default for dmarc_tld_file.  Previously a naiive
      installation would get error messages from DMARC verify, when it hit the
      nonexistent file indicated by the default.  Distros wanting DMARC enabled
      should both provide the file and set the option.
      Also enforce no DMARC verification for command-line sourced messages.

JH/12 Fix an uninitialised flag in early-pipelining.  Previously connections
      could, depending on the platform, hang at the STARTTLS response.

JH/13 Bug 2498: Reset a counter used for ARC verify before handling another
      message on a connection.  Previously if one message had ARC headers and
      the following one did not, a crash could result when adding an
      Authentication-Results: header.

JH/14 Bug 2500: Rewind some of the common-coding in string handling between the
      Exim main code and Exim-related utities.  The introduction of taint
      tracking also did many adjustments to string handling.  Since then, eximon
      frequently terminated with an assert failure.

JH/15 When PIPELINING, synch after every hundred or so RCPT commands sent and
      check for 452 responses.  This slightly helps the inefficieny of doing
      a large alias-expansion into a recipient-limited target.  The max_rcpt
      transport option still applies (and at the current default, will override
      the new feature).  The check is done for either cause of synch, and forces
      a fast-retry of all 452'd recipients using a new MAIL FROM on the same
      connection.  The new facility is not tunable at this time.

JH/16 Fix the variables set by the gsasl authenticator.  Previously a pointer to
      library live data was being used, so the results became garbage.  Make
      copies while it is still usable.

JH/17 Logging: when the deliver_time selector ise set, include the DT= field
      on delivery deferred (==) and failed (**) lines (if a delivery was
      attemtped).  Previously it was only on completion (=>) lines.

JH/18 Authentication: the gsasl driver not provides the $authN variables in time
      for the expansion of the server_scram_iter and server_scram_salt options.

WB/01 SPF: DNS lookups for the obsolete SPF RR type done by the libspf2 library
      are now specifically given a NO_DATA response without hitting the system
      resolver.  The library goes on to do the now-standard TXT lookup.
      Use of dnsdb lookups is not affected.

JH/19 Bug 2507: Modules: on handling a dynamic-module (lookups) open failure,
      only retrieve the errormessage once.  Previously two calls to dlerror()
      were used, and the second one (for mainlog/paniclog) retrieved null
      information.

JH/20 Taint checking: disallow use of tainted data for
      - the appendfile transport file and directory options
      - the pipe transport command
      - the autoreply transport file, log and once options
      - file names used by the redirect router (including filter files)
      - named-queue names
      - paths used by single-key lookups
      Previously this was permitted.

JH/21 Bug 2501: Fix init call in the heimdal authenticator.  Previously it
      adjusted the size of a major service buffer; this failed because the
      buffer was in use at the time.  Change to a compile-time increase in the
      buffer size, when this authenticator is compiled into exim.

JH/22 Taint-checking: move to safe-mode taint checking on all platforms.  The
      previous fast-mode was untenable in the face of glibs using mmap to
      support larger malloc requests.

PP/01 Update the openssl_options possible values through OpenSSL 1.1.1c.
      New values supported, if defined on system where compiled:
      allow_no_dhe_kex, cryptopro_tlsext_bug, enable_middlebox_compat,
      no_anti_replay, no_encrypt_then_mac, prioritize_chacha, tlsext_padding

JH/23 Performance improvement in the initial phase of a two-pass queue run.  By
      running a limited number of proceses in parallel, a benefit is gained. The
      amount varies with the platform hardware and load.  The use of the option
      queue_run_in_order means we cannot do this, as ordering becomes
      indeterminate.

JH/24 Bug 2524: fix the cyrus_sasl auth driver gssapi usage.  A previous fix
      had introduced a string-copy (for ensuring NUL-termination) which was not
      appropriate for that case, which can include embedded NUL bytes in the
      block of data.  Investigation showed the copy to actually be needless, the
      data being length-specified.

JH/25 Fix use of concurrent TLS connections under GnuTLS.  When a callout was
      done during a receiving connection, and both used TLS, global info was
      used rather than per-connection info for tracking the state of data
      queued for transmission.  This could result in a connection hang.

JH/26 Fix use of the SIZE parameter on MAIL commands, on continued connections.
      Previously, when delivering serveral messages down a single connection
      only the first would provide a SIZE.  This was due to the size information
      not being properly tracked.

JH/27 Bug 2530: When operating in a timezone with sub-minute offset, such as
      TAI (at 37 seconds currently), pretend to be in UTC for time-related
      expansion and logging.  Previously, spurious values such as a future
      minute could be seen.

JH/28 Bug 2533: Fix expansion of ${tr } item.  When called in some situations
      it could crash from a null-deref.  This could also affect the
      ${addresses: } operator and ${readsock } item.

JH/29 Bug 2537: Fix $mime_part_count.  When a single connection had a non-mime
      message following a mime one, the variable was not reset.

JH/30 When an pipelined-connect fails at the first response, assume incorrect
      cached capability (perhaps the peer reneged?) and immediately retry in
      non-pipelined mode.

JH/31 Fix spurious detection of timeout while writing to transport filter.

JH/32 Bug 2541: Fix segfault on bad cmdline -f (sender) argument.  Previously
      an attempt to copy the string was made before checking it.

JH/33 Fix the dsearch lookup to return an untainted result.  Previously the
      taint of the lookup key was maintained; we now regard the presence in the
      filesystem as sufficient validation.

JH/34 Fix the readsocket expansion to not segfault when an empty "options"
      argument is supplied.

JH/35 The dsearch lookup now requires that the directory is an absolute path.
      Previously this was not checked, and nonempty relative paths made an
      access under Exim's current working directory.

JH/36 Bug 2554: Fix msg:defer event for the hosts_max_try_hardlimit case.
      Previously no event was raised.

JH/37 Bug 2552: Fix the check on spool space during reception to use the SIZE
      parameter supplied by the sender MAIL FROM command.  Previously it was
      ignored, and only the check_spool_space option value for the required
      leeway checked.

JH/38 Fix $dkim_key_length.  This should, after a DKIM verification, present
      the size of the signing public-key.  Previously it was instead giving
      the size of the signature hash.

JH/39 DKIM verification: the RFC 8301 restriction on sizes of RSA keys is now
      the default.  See the (new) dkim_verify_min_keysizes option.

JH/40 Fix a memory-handling bug: when a connection carried multiple messages
      and an ACL use a lookup for checking either the local_part or domain,
      stale data could be accessed.  Ensure that variable references are
      dropped between messages.

JH/41 Bug 2571: Fix SPA authenticator.  Running as a server, an offset supplied
      by the client was not checked as pointing within response data before
      being used.  A malicious client could thus cause an out-of-bounds read and
      possibly gain authentication.  Fix by adding the check.

JH/42 Internationalisation: change the default for downconversion in the smtp
      transport to be "if needed".  Previously it was "as previously set" for
      the message, which usually meant "if needed" for message-submission but
      "no" for everything else.  However, MTAs have been seen using SMTPUTF8
      even when the envelope addresses did not need it, resulting in forwarding
      failures to non-supporting MTAs.  A downconvert in such cases will be
      a no-op on the addresses, merely dropping the use of SMTPUTF8 by the
      transport.  The change does mean that addresses needing conversion will
      be converted when previously a delivery failure would occur.


Exim version 4.93
-----------------

JH/01 OpenSSL: With debug enabled output keying information sufficient, server
      side, to decode a TLS 1.3 packet capture.

JH/02 OpenSSL: Suppress the sending of (stateful) TLS1.3 session tickets.
      Previously the default library behaviour applied, sending two, each in
      its own TCP segment.

JH/03 Debug output for ACL now gives the config file name and line number for
      each verb.

JH/04 The default received_header_text now uses the RFC 8314 tls cipher clause.

JH/05 DKIM: ensure that dkim_domain elements are lowercased before use.

JH/06 Fix buggy handling of autoreply bounce_return_size_limit, and a possible
      buffer overrun for (non-chunking) other transports.

JH/07 GnuTLS: Our use of late (post-handshake) certificate verification, under
      TLS1.3, means that a server rejecting a client certificate is not visible
      to the client until the first read of encrypted data (typically the
      response to EHLO).  Add detection for that case and treat it as a failed
      TLS connection attempt, so that the normal retry-in-clear can work (if
      suitably configured).

JB/01 Bug 2375: fix expansions of 822 addresses having comments in local-part
      and/or domain.  Found and fixed by Jason Betts.

JH/08 Add hardening against SRV & TLSA lookups the hit CNAMEs (a nonvalid
      configuration).  If a CNAME target was not a wellformed name pattern, a
      crash could result.

JH/09 Logging: Fix initial listening-on line for multiple ports for an IP when
      the OS reports them interleaved with other addresses.

JH/10 OpenSSL: Fix aggregation of messages.  Previously, when PIPELINING was
      used both for input and for a verify callout, both encrypted, SMTP
      responses being sent by the server could be lost.  This resulted in
      dropped connections and sometimes bounces generated by a peer sending
      to this system.

JH/11 Harden plaintext authenticator against a badly misconfigured client-send
      string.  Previously it was possible to cause undefined behaviour in a
      library routine (usually a crash).  Found by "zerons".

JH/12 Bug 2384: fix "-bP smtp_receive_timeout".  Previously it returned no
      output.

JH/13 Bug 2386: Fix builds with Dane under LibreSSL 2.9.0 onward.  Some old
      API was removed, so update to use the newer ones.

JH/14 Bug 1891: Close the log file if receiving a non-smtp message, without
      any timeout set, is taking a long time.  Previously we would hang on to a
      rotated logfile "forever" if the input was arriving with long gaps
      (a previous attempt to fix addressed lack, for a long time, of initial
      input).

HS/01 Bug 2390: Use message_id for tempfile creation to avoid races in a
      shared (NFS) environment. The length of the tempfile name is now
      4 + 16 ("hdr.$message_exim_id") which might break on file
      systems which restrict the file name length to lower values.
      (It was "hdr.$pid".)

HS/02 Bug 2390: Use message_id for tempfile creation to avoid races in a
      shared (NFS) environment.

HS/03 Bug 2392: exigrep does case sensitive *option* processing (as it
      did for all versions <4.90). Notably -M, -m, --invert, -I may be
      affected.

JH/15 Use unsigned when creating bitmasks in macros, to avoid build errors
      on some platforms for bit 31.

JH/16 GnuTLS: rework ciphersuite strings under recent library versions.  Thanks
      to changes apparently associated with TLS1.3 handling some of the APIs
      previously used were either nonfunctional or inappropriate.  Strings
      like TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM__AEAD:256
      and TLS1.2:ECDHE_SECP256R1__RSA_SHA256__AES_128_CBC__SHA256:128 replace
      the previous TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256 .
      This affects log line X= elements, the $tls_{in,out}_cipher variables,
      and the use of specific cipher names in the encrypted= ACL condition.

JH/17 OpenSSL: the default openssl_options now disables ssl_v3.

JH/18 GnuTLS: fix $tls_out_ocsp under hosts_request_ocsp. Previously the
      verification result was not updated unless hosts_require_ocsp applied.

JH/19 Bug 2398: fix listing of a named-queue.  Previously, even with the option
      queue_list_requires_admin set to false, non-admin users were denied the
      facility.

JH/20 Bug 2389: fix server advertising of usable certificates, under GnuTLS in
      directory-of-certs mode.  Previously they were advertised despite the
      documentation.

JH/21 The smtp transport option "hosts_noproxy_tls" is now unset by default.
      A single TCP connection by a client will now hold a TLS connection open
      for multiple message deliveries, by default.  Previoud the default was to
      not do so.

JH/22 The smtp transport option "hosts_try_dane" now enables all hosts by
      default.  If built with the facility, DANE will be used.  The facility
      SUPPORT_DANE is now enabled in the prototype build Makefile "EDITME".

JH/23 The build default is now for TLS to be included; the SUPPORT_TLS define
      is replaced with DISABLE_TLS.  Either USE_GNUTLS or (the new) USE_OPENSSL
      must be defined and you must still, unless you define DISABLE_TLS, manage
      the the include-dir and library-file requirements that go with that
      choice.  Non-TLS builds are still supported.

JH/24 Fix duplicated logging of peer name/address, on a transport connection-
      reject under TFO.

JH/25 The smtp transport option "hosts_try_fastopen" now enables all hosts by
      default.  If the platform supports and has the facility enabled, it will
      be requested on all coneections.

JH/26 The PIPE_CONNECT facility is promoted from experimental status and is now
      controlled by the build-time option SUPPORT_PIPE_CONNECT.

PP/01 Unbreak heimdal_gssapi, broken in 4.92.

JH/27 Bug 2404: Use the main-section configuration option "dsn_from" for
      success-DSN messages.  Previously the From: header was always the default
      one for these; the option was ignored.

JH/28 Fix the timeout on smtp response to apply to the whole response.
      Previously it was reset for every read, so a teergrubing peer sending
      single bytes within the time limit could extend the connection for a
      long time.  Credit to Qualsys Security Advisory Team for the discovery.

JH/29 Fix DSN Final-Recipient: field.  Previously it was the post-routing
      delivery address, which leaked information of the results of local
      forwarding.  Change to the original envelope recipient address, per
      standards.

JH/30 Bug 2411: Fix DSN generation when RFC 3461 failure notification is
      requested.  Previously not bounce was generated and a log entry of
      error ignored was made.

JH/31 Avoid re-expansion in ${sort } expansion. (CVE-2019-13917)

JH/32 Introduce a general tainting mechanism for values read from the input
      channel, and values derived from them.  Refuse to expand any tainted
      values, to catch one form of exploit.

JH/33 Bug 2413: Fix dkim_strict option.  Previously the expansion result
      was unused and the unexpanded text used for the test.  Found and
      fixed by Ruben Jenster.

JH/34 Fix crash after TLS shutdown.  When the TCP/SMTP channel was left open,
      an attempt to use a TLS library read routine dereffed a nul pointer,
      causing a segfault.

JH/35 Bug 2409: filter out-of-spec chars from callout response before using
      them in our smtp response.

JH/36 Have the general router option retry_use_local_part default to true when
      any of the restrictive preconditions are set (to anything).  Previously it
      was only for check_local user.  The change removes one item of manual
      configuration which is required for proper retries when a remote router
      handles a subset of addresses for a domain.

JH/37 Appendfile: when evaluating quota use (non-quota_size_regex) take the file
      link count into consideration.

HS/04 Fix handling of very log lines in -H files. If a -<key> <value> line
      caused the extension of big_buffer, the following lines were ignored.

JH/38 Bug 1395: Teach the DNS negative-cache about TTL value from the SOA in
      accordance with RFC 2308.  Previously there was no expiry, so a longlived
      receive process (eg. due to ACL delays) versus a short SOA value could
      surprise.

HS/05 Handle trailing backslash gracefully. (CVE-2019-15846)

JH/39 Promote DMARC support to mainline.

JH/40 Bug 2452: Add a References: header to DSNs.

JH/41 With GnuTLS 3.6.0 (and later) do not attempt to manage Diffie-Hellman
      parameters.  The relevant library call is documented as "Deprecated: This
      function is unnecessary and discouraged on GnuTLS 3.6.0 or later. Since
      3.6.0, DH parameters are negotiated following RFC7919."

HS/06 Change the default of dnssec_request_domains to "*"

JH/42 Bug 2545: Fix CHUNKING for all RCPT commands rejected.  Previously we
      carried on and emitted a BDAT command, even when PIPELINING was not
      active.

JH/43 Bug 2465: Fix taint-handling in dsearch lookup.  Previously a nontainted
      buffer was used for the filename, resulting in a trap when tainted
      arguments (eg. $domain) were used.

JH/44 With OpenSSL 1.1.1 (onwards) disable renegotiation for TLS1.2 and below;
      recommended to avoid a possible server-load attack.  The feature can be
      re-enabled via the openssl_options main cofiguration option.

JH/45 local_scan API: documented the current smtp_printf() call. This changed
      for version 4.90 - adding a "more data" boolean to the arguments.
      Bumped the ABI version number also, this having been missed previously;
      release versions 4.90 to 4.92.3 inclusive were effectively broken in
      respect of usage of smtp_printf() by either local_scan code or libraries
      accessed via the ${dlfunc } expansion item.  Both will need coding
      adjustment for any calls to smtp_printf() to match the new function
      signature; a FALSE value for the new argument is always safe.

JH/46 FreeBSD: fix use of the sendfile() syscall.  The shim was not updating
      the file-offset (which the Linux syscall does, and exim expects); this
      resulted in an indefinite loop.

JH/47 ARC: fix crash in signing, triggered when a configuration error failed
      to do ARC verification.  The Authentication-Results: header line added
      by the configuration then had no ARC item.


Exim version 4.92
-----------------

JH/01 Remove code calling the customisable local_scan function, unless a new
      definition "HAVE_LOCAL_SCAN=yes" is present in the Local/Makefile.

JH/02 Bug 1007: Avoid doing logging from signal-handlers, as that can result in
      non-signal-safe functions being used.

JH/03 Bug 2269: When presented with a received message having a stupidly large
      number of DKIM-Signature headers, disable DKIM verification to avoid
      a resource-consumption attack.  The limit is set at twenty.

JH/04 Add variables $arc_domains, $arc_oldest_pass for ARC verify.  Fix the
      report of oldest_pass in ${authres } in consequence, and separate out
      some descriptions of reasons for verification fail.

JH/05 Bug 2273: Cutthrough delivery left a window where the received messsage
      files in the spool were present and unlocked.  A queue-runner could spot
      them, resulting in a duplicate delivery.  Fix that by doing the unlock
      after the unlink.  Investigation by Tim Stewart.  Take the opportunity to
      add more error-checking on spoolfile handling while that code is being
      messed with.

PP/01 Refuse to open a spool data file (*-D) if it's a symlink.
      No known attacks, no CVE, this is defensive hardening.

JH/06 Bug 2275: The MIME ACL unlocked the received message files early, and
      a queue-runner could start a delivery while other operations were ongoing.
      Cutthrough delivery was a common victim, resulting in duplicate delivery.
      Found and investigated by Tim Stewart.  Fix by using the open message data
      file handle rather than opening another, and not locally closing it (which
      releases a lock) for that case, while creating the temporary .eml format
      file for the MIME ACL.  Also applies to "regex" and "spam" ACL conditions.

JH/07 Bug 177: Make a random-recipient callout success visible in ACL, by setting
      $sender_verify_failure/$recipient_verify_failure to "random".

JH/08 When generating a selfsigned cert, use serial number 1 since zero is not
      legitimate.

JH/09 Bug 2274: Fix logging of cmdline args when starting in an unlinked cwd.
      Previously this would segfault.

JH/10 Fix ARC signing for case when DKIM signing failed.  Previously this would
      segfault.

JH/11 Bug 2264: Exim now only follows CNAME chains one step by default. We'd
      like zero, since the resolver should be doing this for us, But we need one
      as a CNAME but no MX presence gets the CNAME returned; we need to check
      that doesn't point to an MX to declare it "no MX returned" rather than
      "error, loop".  A new main option is added so the older capability of
      following some limited number of chain links is maintained.

JH/12 Add client-ip info to non-pass iprev ${authres } lines.

JH/13 For receent Openssl versions (1.1 onward) use modern generic protocol
      methods.  These should support TLS 1.3; they arrived with TLS 1.3 and the
      now-deprecated earlier definitions used only specified the range up to TLS
      1.2 (in the older-version library docs).

JH/14 Bug 2284: Fix DKIM signing for body lines starting with a pair of dots.

JH/15 Rework TLS client-side context management.  Stop using a global, and
      explicitly pass a context around.  This enables future use of TLS for
      connections to service-daemons (eg. malware scanning) while a client smtp
      connection is using TLS; with cutthrough connections this is quite likely.

JH/16 Fix ARC verification to do AS checks in reverse order.

JH/17 Support a "tls" option on the ${readsocket } expansion item.

JH/18 Bug 2287: Fix the protocol name (eg utf8esmtp) for multiple messages
      using the SMTPUTF8 option on their MAIL FROM commands, in one connection.
      Previously the "utf8" would be re-prepended for every additional message.

JH/19 Reject MAIL FROM commands with SMTPUTF8 when the facility was not advertised.
      Previously thery were accepted, resulting in issues when attempting to
      forward messages to a non-supporting MTA.

PP/02 Let -n work with printing macros too, not just options.

JH/20 Bug 2296: Fix cutthrough for >1 address redirection.  Previously only
      one parent address was copied, and bogus data was used at delivery-logging
      time.  Either a crash (after delivery) or bogus log data could result.
      Discovery and analysis by Tim Stewart.

PP/03 Make ${utf8clean:} expansion operator detect incomplete final character.
      Previously if the string ended mid-character, we did not insert the
      promised '?' replacement.

PP/04 Documentation: current string operators work on bytes, not codepoints.

JH/21 Change as many as possible of the global flags into one-bit bitfields; these
      should pack well giving a smaller memory footprint so better caching and
      therefore performance.  Group the declarations where this can't be done so
      that the byte-sized flag variables are not interspersed among pointer
      variables, giving a better chance of good packing by the compiler.

JH/22 Bug 1896: Fix the envelope from for DMARC forensic reports to be possibly
      non-null, to avoid issues with sites running BATV.  Previously reports were
      sent with an empty envelope sender so looked like bounces.

JH/23 Bug 2318: Fix the noerror command within filters.  It wasn't working.
      The ignore_error flag wasn't being returned from the filter subprocess so
      was not set for later routers.  Investigation and fix by Matthias Kurz.

JH/24 Bug 2310: Raise a msg:fail:internal event for each undelivered recipient,
      and a msg:complete for the whole, when a message is manually removed using
      -Mrm.  Developement by Matthias Kurz, hacked on by JH.

JH/25 Avoid fixed-size buffers for pathnames in DB access.  This required using
      a "Gnu special" function, asprintf() in the DB utility binary builds; I
      hope that is portable enough.

JH/26 Bug 2311: Fix DANE-TA verification under GnuTLS.  Previously it was also
      requiring a known-CA anchor certificate; make it now rely entirely on the
      TLSA as an anchor.  Checking the name on the leaf cert against the name
      on the A-record for the host is still done for TA (but not for EE mode).

JH/27 Fix logging of proxy address.  Previously, a pointless "PRX=[]:0" would be
      included in delivery lines for non-proxied connections, when compiled with
      SUPPORT_SOCKS and running with proxy logging enabled.

JH/28 Bug 2314: Fire msg:fail:delivery event even when error is being ignored.
      Developement by Matthias Kurz, tweaked by JH.  While in that bit of code,
      move the existing event to fire before the normal logging of message
      failure so that custom logging is bracketed by normal logging.

JH/29 Bug 2322: A "fail" command in a non-system filter (file) now fires the
      msg:fail:internal event.  Developement by Matthias Kurz.

JH/30 Bug 2329: Increase buffer size used for dns lookup from 2k, which was
      far too small for todays use of crypto signatures stored there.  Go all
      the way to the max DNS message size of 64kB, even though this might be
      overmuch for IOT constrained device use.

JH/31 Fix a bad use of a copy function, which could be used to pointlessly
      copy a string over itself.  The library routine is documented as not
      supporting overlapping copies, and on MacOS it actually raised a SIGABRT.

JH/32 For main options check_spool_space and check_inode_space, where the
      platform supports 64b integers, support more than the previous 2^31 kB
      (i.e. more than 2 TB).  Accept E, P and T multipliers in addition to
      the previous G, M, k.

JH/33 Bug 2338: Fix the cyrus-sasl authenticator to fill in the
      $authenticated_fail_id variable on authentication failure.  Previously
      it was unset.

JH/34 Increase RSA keysize of autogen selfsign cert from 1024 to 2048.  RHEL 8.0
      OpenSSL didn't want to use such a weak key.  Do for GnuTLS also, and for
      more-modern GnuTLS move from GNUTLS_SEC_PARAM_LOW to
      GNUTLS_SEC_PARAM_MEDIUM.

JH/35 OpenSSL: fail the handshake when SNI processing hits a problem, server
      side.  Previously we would continue as if no SNI had been received.

JH/36 Harden the handling of string-lists.  When a list consisted of a sole
      "<" character, which should be a list-separator specification, we walked
      off past the nul-terimation.

JH/37 Bug 2341: Send "message delayed" warning MDNs (restricted to external
      causes) even when the retry time is not yet met.  Previously they were
      not, meaning that when (say) an account was over-quota and temp-rejecting,
      and multiple senders' messages were queued, only one sender would get
      notified on each configured delay_warning cycle.

JH/38 Bug 2351: Log failures to extract envelope addresses from message headers.

JH/39 OpenSSL: clear the error stack after an SSL_accept().  With anon-auth
      cipher-suites, an error can be left on the stack even for a succeeding
      accept; this results in impossible error messages when a later operation
      actually does fail.

AM/01 Bug 2359: GnuTLS: repeat lowlevel read and write operations while they
      return error codes indicating retry.  Under TLS1.3 this becomes required.

JH/40 Fix the feature-cache refresh for EXPERIMENTAL_PIPE_CONNECT.  Previously
      it only wrote the new authenticators, resulting in a lack of tracking of
      peer changes of ESMTP extensions until the next cache flush.

JH/41 Fix the loop reading a message header line to check for integer overflow,
      and more-often against header_maxsize.  Previously a crafted message could
      induce a crash of the recive process; now the message is cleanly rejected.

JH/42 Bug 2366: Fix the behaviour of the dkim_verify_signers option.  It had
      been totally disabled for all of 4.91.  Discovery and fix by "Mad Alex".


Exim version 4.91
-----------------

GF/01 DEFER rather than ERROR on redis cluster MOVED response.
      When redis_servers is set to a list of > 1 element, and the Redis servers
      in that list are in cluster configuration, convert the REDIS_REPLY_ERROR
      case of MOVED into a DEFER case instead, thus moving the query onto the
      next server in the list. For a cluster of N elements, all N servers must
      be defined in redis_servers.

GF/02 Catch and remove uninitialized value warning in exiqsumm
      Check for existence of @ARGV before looking at $ARGV[0]

JH/01 Replace the store_release() internal interface with store_newblock(),
      which internalises the check required to safely use the old one, plus
      the allocate and data copy operations duplicated in both (!) of the
      extant use locations.

JH/02 Disallow '/' characters in queue names specified for the "queue=" ACL
      modifier.  This matches the restriction on the commandline.

JH/03 Fix pgsql lookup for multiple result-tuples with a single column.
      Previously only the last row was returned.

JH/04 Bug 2217: Tighten up the parsing of DKIM signature headers. Previously
      we assumed that tags in the header were well-formed, and parsed the
      element content after inspecting only the first char of the tag.
      Assumptions at that stage could crash the receive process on malformed
      input.

JH/05 Bug 2215: Fix crash associated with dnsdb lookup done from DKIM ACL.
      While running the DKIM ACL we operate on the Permanent memory pool so that
      variables created with "set" persist to the DATA ACL.  Also (at any time)
      DNS lookups that fail create cache records using the Permanent pool.  But
      expansions release any allocations made on the current pool - so a dnsdb
      lookup expansion done in the DKIM ACL releases the memory used for the
      DNS negative-cache, and bad things result.  Solution is to switch to the
      Main pool for expansions.
      While we're in that code, add checks on the DNS cache during store_reset,
      active in the testsuite.
      Problem spotted, and debugging aided, by Wolfgang Breyha.

JH/06 Fix issue with continued-connections when the DNS shifts unreliably.
      When none of the hosts presented to a transport match an already-open
      connection, close it and proceed with the list.  Previously we would
      queue the message.  Spotted by Lena with Yahoo, probably involving
      round-robin DNS.

JH/07 Bug 2214: Fix SMTP responses resulting from non-accept result of MIME ACL.
      Previously a spurious "250 OK id=" response was appended to the proper
      failure response.

JH/08 The "support for" informational output now, which built with Content
      Scanning support, has a line for the malware scanner interfaces compiled
      in.  Interface can be individually included or not at build time.

JH/09 The "aveserver", "kavdaemon" and "mksd" interfaces are now not included
      by the template makefile "src/EDITME".  The "STREAM" support for an older
      ClamAV interface method is removed.

JH/10 Bug 2223: Fix mysql lookup returns for the no-data case (when the number of
      rows affected is given instead).

JH/11 The runtime Berkeley DB library version is now additionally output by
      "exim -d -bV".  Previously only the compile-time version was shown.

JH/12 Bug 2230: Fix cutthrough routing for nonfirst messages in an initiating
      SMTP connection.  Previously, when one had more receipients than the
      first, an abortive onward connection was made.  Move to full support for
      multiple onward connections in sequence, handling cutthrough connection
      for all multi-message initiating connections.

JH/13 Bug 2229: Fix cutthrough routing for nonstandard port numbers defined by
      routers.  Previously, a multi-recipient message would fail to match the
      onward-connection opened for the first recipient, and cause its closure.

JH/14 Bug 2174: A timeout on connect for a callout was also erroneously seen as
      a timeout on read on a GnuTLS initiating connection, resulting in the
      initiating connection being dropped.  This mattered most when the callout
      was marked defer_ok.  Fix to keep the two timeout-detection methods
      separate.

JH/15 Relax results from ACL control request to enable cutthrough, in
      unsupported situations, from error to silently (except under debug)
      ignoring.  This covers use with PRDR, frozen messages, queue-only and
      fake-reject.

HS/01 Fix Buffer overflow in base64d() (CVE-2018-6789)

JH/16 Fix bug in DKIM verify: a buffer overflow could corrupt the malloc
      metadata, resulting in a crash in free().

PP/01 Fix broken Heimdal GSSAPI authenticator integration.
      Broken in f2ed27cf5, missing an equals sign for specified-initialisers.
      Broken also in d185889f4, with init system revamp.

JH/17 Bug 2113: Fix conversation closedown with the Avast malware scanner.
      Previously we abruptly closed the connection after reading a malware-
      found indication; now we go on to read the "scan ok" response line,
      and send a quit.

JH/18 Bug 2239: Enforce non-usability of control=utf8_downconvert in the mail
      ACL.  Previously, a crash would result.

JH/19 Speed up macro lookups during configuration file read, by skipping non-
      macro text after a replacement (previously it was only once per line) and
      by skipping builtin macros when searching for an uppercase lead character.

JH/20 DANE support moved from Experimental to mainline.  The Makefile control
      for the build is renamed.

JH/21 Fix memory leak during multi-message connections using STARTTLS.  A buffer
      was allocated for every new TLS startup, meaning one per message.  Fix
      by only allocating once (OpenSSL) or freeing on TLS-close (GnuTLS).

JH/22 Bug 2236: When a DKIM verification result is overridden by ACL, DMARC
      reported the original.  Fix to report (as far as possible) the ACL
      result replacing the original.

JH/23 Fix memory leak during multi-message connections using STARTTLS under
      OpenSSL.  Certificate information is loaded for every new TLS startup,
      and the resources needed to be freed.

JH/24 Bug 2242: Fix exim_dbmbuild to permit directoryless filenames.

JH/25 Fix utf8_downconvert propagation through a redirect router.  Previously it
      was not propagated.

JH/26 Bug 2253: For logging delivery lines under PRDR, append the overall
      DATA response info to the (existing) per-recipient response info for
      the "C=" log element.  It can have useful tracking info from the
      destination system.  Patch from Simon Arlott.

JH/27 Bug 2251: Fix ldap lookups that return a single attribute having zero-
      length value.  Previously this would segfault.

HS/02 Support Avast multiline protoocol, this allows passing flags to
      newer versions of the scanner.

JH/28 Ensure that variables possibly set during message acceptance are marked
      dead before release of memory in the daemon loop.  This stops complaints
      about them when the debug_store option is enabled.  Discovered specifically
      for sender_rate_period, but applies to a whole set of variables.
      Do the same for the queue-runner and queue-list loops, for variables set
      from spool message files.  Do the same for the SMTP per-message loop, for
      certain variables indirectly set in ACL operations.

JH/29 Bug 2250: Fix a longstanding bug in heavily-pipelined SMTP input (such
      as a multi-recipient message from a mailinglist manager).  The coding had
      an arbitrary cutoff number of characters while checking for more input;
      enforced by writing a NUL into the buffer.  This corrupted long / fast
      input.   The problem was exposed more widely when more pipelineing of SMTP
      responses was introduced, and one Exim system was feeding another.
      The symptom is log complaints of SMTP syntax error (NUL chars) on the
      receiving system, and refused recipients seen by the sending system
      (propating to people being dropped from mailing lists).
      Discovered and pinpointed by David Carter.

JH/30 The (EXPERIMENTAL_DMARC) variable $dmarc_ar_header is withdrawn, being
      replaced by the ${authresults } expansion.

JH/31 Bug 2257: Fix pipe transport to not use a socket-only syscall.

HS/03 Set a handler for SIGTERM and call exit(3) if running as PID 1. This
      allows proper process termination in container environments.

JH/32 Bug 2258: Fix spool_wireformat in combination with LMTP transport.
      Previously the "final dot" had a newline after it; ensure it is CR,LF.

JH/33 SPF: remove support for the "spf" ACL condition outcome values "err_temp"
      and "err_perm", deprecated since 4.83 when the RFC-defined words
      "temperror" and "permerror" were introduced.

JH/34 Re-introduce enforcement of no cutthrough delivery on transports having
      transport-filters or DKIM-signing.  The restriction was lost in the
      consolidation of verify-callout and delivery SMTP handling.
      Extend the restriction to also cover ARC-signing.

JH/35 Cutthrough: for a final-dot response timeout (and nonunderstood responses)
      in defer=pass mode supply a 450 to the initiator.  Previously the message
      would be spooled.

PP/02 DANE: add dane_require_tls_ciphers SMTP Transport option; if unset,
      tls_require_ciphers is used as before.

HS/03 Malware Avast: Better match the Avast multiline protocol. Add
      "pass_unscanned".  Only tmpfails from the scanner are written to
      the paniclog, as they may require admin intervention (permission
      denied, license issues). Other scanner errors (like decompression
      bombs) do not cause a paniclog entry.

JH/36 Fix reinitialisation of DKIM logging variable between messages.
      Previously it was possible to log spurious information in receive log
      lines.

JH/37 Bug 2255: Revert the disable of the OpenSSL session caching.  This
      triggered odd behaviour from Outlook Express clients.

PP/03 Add util/renew-opendmarc-tlds.sh script for safe renewal of public
      suffix list.

JH/38 DKIM: accept Ed25519 pubkeys in SubjectPublicKeyInfo-wrapped form,
      since the IETF WG has not yet settled on that versus the original
      "bare" representation.

JH/39 Fix syslog logging for syslog_timestamp=no and log_selector +millisec.
      Previously the millisecond value corrupted the output.
      Fix also for syslog_pid=no and log_selector +pid, for which the pid
      corrupted the output.


Exim version 4.90
-----------------

JH/01 Rework error string handling in TLS interface so that the caller in
      more cases is responsible for logging.  This permits library-sourced
      string to be attached to addresses during delivery, and collapses
      pairs of long lines into single ones.

PP/01 Allow PKG_CONFIG_PATH to be set in Local/Makefile and use it correctly
      during configuration.  Wildcards are allowed and expanded.

JH/02 Rework error string handling in DKIM to pass more info back to callers.
      This permits better logging.

JH/03 Rework the transport continued-connection mechanism: when TLS is active,
      do not close it down and have the child transport start it up again on
      the passed-on TCP connection.  Instead, proxy the child (and any
      subsequent ones) for TLS via a unix-domain socket channel.  Logging is
      affected: the continued delivery log lines do not have any DNSSEC, TLS
      Certificate or OCSP information.  TLS cipher information is still logged.

JH/04 Shorten the log line for daemon startup by collapsing adjacent sets of
      identical IP addresses on different listening ports.  Will also affect
      "exiwhat" output.

PP/02 Bug 2070: uClibc defines __GLIBC__ without providing glibc headers;
      add noisy ifdef guards to special-case this sillyness.
      Patch from Bernd Kuhls.

JH/05 Tighten up the checking in isip4 (et al): dotted-quad components larger
      than 255 are no longer allowed.

JH/06 Default openssl_options to include +no_ticket, to reduce load on peers.
      Disable the session-cache too, which might reduce our load.  Since we
      currrectly use a new context for every connection, both as server and
      client, there is no benefit for these.
      GnuTLS appears to not support tickets server-side by default (we don't
      call gnutls_session_ticket_enable_server()) but client side is enabled
      by default on recent versions (3.1.3 +) unless the PFS priority string
      is used (3.2.4 +).

PP/03 Add $SOURCE_DATE_EPOCH support for reproducible builds, per spec at
      <https://reproducible-builds.org/specs/source-date-epoch/>.

JH/07 Fix smtp transport use of limited max_rcpt under mua_wrapper. Previously
      the check for any unsuccessful recipients did not notice the limit, and
      erroneously found still-pending ones.

JH/08 Pipeline CHUNKING command and data together, on kernels that support
      MSG_MORE.  Only in-clear (not on TLS connections).

JH/09 Avoid using a temporary file during transport using dkim.  Unless a
      transport-filter is involved we can buffer the headers in memory for
      creating the signature, and read the spool data file once for the
      signature and again for transmission.

JH/10 Enable use of sendfile in Linux builds as default.  It was disabled in
      4.77 as the kernel support then wasn't solid, having issues in 64bit
      mode.  Now, it's been long enough.  Add support for FreeBSD also.

JH/11 Bug 2104: Fix continued use of a transport connection with TLS.  In the
      case where the routing stage had gathered several addresses to send to
      a host before calling the transport for the first, we previously failed
      to close down TLS in the old transport process before passing the TCP
      connection to the new process.  The new one sent a STARTTLS command
      which naturally failed, giving a failed delivery and bloating the retry
      database.  Investigation and fix prototype from Wolfgang Breyha.

JH/12 Fix check on SMTP command input synchronisation.  Previously there were
      false-negatives in the check that the sender had not preempted a response
      or prompt from Exim (running as a server), due to that code's lack of
      awareness of the SMTP input buffering.

PP/04 Add commandline_checks_require_admin option.
      Exim drops privileges sanely, various checks such as -be aren't a
      security problem, as long as you trust local users with access to their
      own account.  When invoked by services which pass untrusted data to
      Exim, this might be an issue.  Set this option in main configuration
      AND make fixes to the calling application, such as using `--` to stop
      processing options.

JH/13 Do pipelining under TLS.  Previously, although safe, no advantage was
      taken.  Now take care to pack both (client) MAIL,RCPT,DATA, and (server)
      responses to those, into a single TLS record each way (this usually means
      a single packet).  As a side issue, smtp_enforce_sync now works on TLS
      connections.

PP/05 OpenSSL/1.1: use DH_bits() for more accurate DH param sizes.  This
      affects you only if you're dancing at the edge of the param size limits.
      If you are, and this message makes sense to you, then: raise the
      configured limit or use OpenSSL 1.1.  Nothing we can do for older
      versions.

JH/14 For the "sock" variant of the malware scanner interface, accept an empty
      cmdline element to get the documented default one.  Previously it was
      inaccessible.

JH/15 Fix a crash in the smtp transport caused when two hosts in succession
      are unsuable for non-message-specific reasons - eg. connection timeout,
      banner-time rejection.

JH/16 Fix logging of delivery remote port, when specified by router, under
      callout/hold.

PP/06 Repair manualroute's ability to take options in any order, even if one
      is the name of a transport.
      Fixes bug 2140.

HS/01 Cleanup, prevent repeated use of -p/-oMr (CVE-2017-1000369)

JH/17 Change the list-building routines interface to use the expanding-string
      triplet model, for better allocation and copying behaviour.

JH/18 Prebuild the data-structure for "builtin" macros, for faster startup.
      Previously it was constructed the first time a possibly-matching string
      was met in the configuration file input during startup; now it is done
      during compilation.

JH/19 Bug 2141: Use the full-complex API for Berkeley DB rather than the legacy-
      compatible one, to avoid the (poorly documented) possibility of a config
      file in the working directory redirecting the DB files, possibly correpting
      some existing file.  CVE-2017-10140 assigned for BDB.

JH/20 Bug 2147: Do not defer for a verify-with-callout-and-random which is not
      cache-hot.  Previously, although the result was properly cached, the
      initial verify call returned a defer.

JH/21 Bug 2151: Avoid using SIZE on the MAIL for a callout verify, on any but
      the main verify for receipient in uncached-mode.

JH/22 Retire historical build files to an "unsupported" subdir.  These are
      defined as "ones for which we have no current evidence of testing".

JH/23 DKIM: enforce the DNS pubkey record "h" permitted-hashes optional field,
      if present.  Previously it was ignored.

JH/24 Start using specified-initialisers in C structure init coding.  This is
      a C99 feature (it's 2017, so now considered safe).

JH/25 Use one-bit bitfields for flags in the "addr" data structure.  Previously
      if was a fixed-sized field and bitmask ops via macros; it is now more
      extensible.

PP/07 GitHub PR 56: Apply MariaDB build fix.
      Patch provided by Jaroslav Škarvada.

PP/08 Bug 2161: Fix regression in sieve quoted-printable handling introduced
      during Coverity cleanups [4.87 JH/47]
      Diagnosis and fix provided by Michael Fischer v. Mollard.

JH/26 Fix DKIM bug: when the pseudoheader generated for signing was exactly
      the right size to place the terminating semicolon on its own folded
      line, the header hash was calculated to an incorrect value thanks to
      the (relaxed) space the fold became.

HS/02 Fix Bug 2130: large writes from the transport subprocess were chunked
      and confused the parent.

JH/27 Fix SOCKS bug: an unitialized pointer was deref'd by the transport process
      which could crash as a result.  This could lead to undeliverable messages.

JH/28 Logging: "next input sent too soon" now shows where input was truncated
      for log purposes.

JH/29 Fix queue_run_in_order to ignore the PID portion of the message ID.  This
      matters on fast-turnover and PID-randomising systems, which were getting
      out-of-order delivery.

JH/30 Fix a logging bug on aarch64: an unsafe routine was previously used for
      a possibly-overlapping copy.  The symptom was that "Remote host closed
      connection in response to HELO" was logged instead of the actual 4xx
      error for the HELO.

JH/31 Fix CHUNKING code to properly flush the unwanted chunk after an error.
      Previously only that bufferd was discarded, resulting in SYMTP command
      desynchronisation.

JH/32 DKIM: when a message has multiple signatures matching an identity given
      in dkim_verify_signers, run the dkim acl once for each.  Previously only
      one run was done.  Bug 2189.

JH/33 Downgrade an unfound-list name (usually a typo in the config file) from
      "panic the current process" to "deliberately defer".  The panic log is
      still written with the problem list name; the mail and reject logs now
      get a temp-reject line for the message that was being handled, saying
      something like "domains check lookup or other defer".  The SMTP 451
      message is still "Temporary local problem".

JH/34 Bug 2199: Fix a use-after-free while reading smtp input for header lines.
      A crafted sequence of BDAT commands could result in in-use memory beeing
      freed.  CVE-2017-16943.

HS/03 Bug 2201: Fix checking for leading-dot on a line during headers reading
      from SMTP input.  Previously it was always done; now only done for DATA
      and not BDAT commands.  CVE-2017-16944.

JH/35 Bug 2201: Flush received data in BDAT mode after detecting an error fatal
      to the message (such as an overlong header line).  Previously this was
      not done and we did not exit BDAT mode.  Followon from the previous item
      though a different problem.


Exim version 4.89
-----------------

JH/01 Bug 1922: Support IDNA2008.  This has slightly different conversion rules
      than -2003 did; needs libidn2 in addition to libidn.

JH/02 The path option on a pipe transport is now expanded before use.

PP/01 GitHub PR 50: Do not call ldap_start_tls_s on ldapi:// connections.
      Patch provided by "Björn", documentation fix added too.

JH/03 Bug 2003: fix Proxy Protocol v2 handling: the address size field was
      missing a wire-to-host endian conversion.

JH/04 Bug 2004: fix CHUNKING in non-PIPELINEING mode.  Chunk data following
      close after a BDAT command line could be taken as a following command,
      giving a synch failure.  Fix by only checking for synch immediately
      before acknowledging the chunk.

PP/02 GitHub PR 52: many spelling fixes, which include fixing parsing of
      no_require_dnssec option and creation of _HAVE_TRANSPORT_APPEND_MAILDIR
      macro.  Patches provided by Josh Soref.

JH/05 Have the EHLO response advertise VRFY, if there is a vrfy ACL defined.
      Previously we did not; the RFC seems ambiguous and VRFY is not listed
      by IANA as a service extension.  However, John Klensin suggests that we
      should.

JH/06 Bug 2017: Fix DKIM verification in -bh test mode.  The data feed into
      the dkim code may be unix-mode line endings rather than smtp wire-format
      CRLF, so prepend a CR to any bare LF.

JH/07 Rationalise the coding for callout smtp conversations and transport ones.
      As a side-benfit, callouts can now use PIPELINING hence fewer round-trips.

JH/08 Bug 2016: Fix DKIM verification vs. CHUNKING.  Any BDAT commands after
      the first were themselves being wrongly included in the feed into dkim
      processing; with most chunk sizes in use this resulted in an incorrect
      body hash calculated value.

JH/09 Bug 2014: permit inclusion of a DKIM-Signature header in a received
      DKIM signature block, for verification.  Although advised against by
      standards it is specifically not ruled illegal.

JH/10 Bug 2025: Fix reception of (quoted) local-parts with embedded spaces.

JH/11 Bug 2029: Fix crash in DKIM verification when a message signature block is
      missing a body hash (the bh= tag).

JH/12 Bug 2018: Re-order Proxy Protocol startup versus TLS-on-connect startup.
      It seems that HAProxy sends the Proxy Protocol information in clear and
      only then does a TLS startup, so do the same.

JH/13 Bug 2027: Avoid attempting to use TCP Fast Open for non-transport client
      TCP connections (such as for Spamd) unless the daemon successfully set
      Fast Open mode on its listening sockets.  This fixes breakage seen on
      too-old kernels or those not configured for Fast Open, at the cost of
      requiring both directions being enabled for TFO, and TFO never being used
      by non-daemon-related Exim processes.

JH/14 Bug 2000: Reject messages recieved with CHUNKING but with malformed line
      endings, at least on the first header line.  Try to canonify any that get
      past that check, despite the cost.

JH/15 Angle-bracket nesting (an error inserted by broken sendmails) levels are
      now limited to an arbitrary five deep, while parsing addresses with the
      strip_excess_angle_brackets option enabled.

PP/03 Bug 2018: For Proxy Protocol and TLS-on-connect, do not over-read and
      instead leave the unprompted TLS handshake in socket buffer for the
      TLS library to consume.

PP/04 Bug 2018: Also handle Proxy Protocol v2 safely.

PP/05 FreeBSD compat: handle that Ports no longer create /usr/bin/perl

JH/16 Drop variables when they go out of scope.  Memory management drops a whole
      region in one operation, for speed, and this leaves assigned pointers
      dangling.  Add checks run only under the testsuite which checks all
      variables at a store-reset and panics on a dangling pointer; add code
      explicitly nulling out all the variables discovered.  Fixes one known
      bug: a transport crash, where a dangling pointer for $sending_ip_address
      originally assigned in a verify callout, is re-used.

PP/06 Drop '.' from @INC in various Perl scripts.

PP/07 Switch FreeBSD iconv to always use the base-system libc functions.

PP/08 Reduce a number of compilation warnings under clang; building with
      CC=clang CFLAGS+=-Wno-dangling-else -Wno-logical-op-parentheses
      should be warning-free.

JH/17 Fix inbound CHUNKING when DKIM disabled at runtime.

HS/01 Fix portability problems introduced by PP/08 for platforms where
      realloc(NULL) is not equivalent to malloc() [SunOS et al].

HS/02 Bug 1974: Fix missing line terminator on the last received BDAT
      chunk. This allows us to accept broken chunked messages. We need a more
      general solution here.

PP/09 Wrote util/chunking_fixqueue_finalnewlines.pl to help recover
      already-broken messages in the queue.

JH/18 Bug 2061: Fix ${extract } corrupting an enclosing ${reduce }  $value.

JH/19 Fix reference counting bug in routing-generated-address tracking.


Exim version 4.88
-----------------

JH/01 Use SIZE on MAIL FROM in a cutthrough connection, if the destination
      supports it and a size is available (ie. the sending peer gave us one).

JH/02 The obsolete acl condition "demime" is removed (finally, after ten
      years of being deprecated). The replacements are the ACLs
      acl_smtp_mime and acl_not_smtp_mime.

JH/03 Upgrade security requirements imposed for hosts_try_dane: previously
      a downgraded non-dane trust-anchor for the TLS connection (CA-style)
      or even an in-clear connection were permitted.  Now, if the host lookup
      was dnssec and dane was requested then the host is only used if the
      TLSA lookup succeeds and is dnssec.  Further hosts (eg. lower priority
      MXs) will be tried (for hosts_try_dane though not for hosts_require_dane)
      if one fails this test.
      This means that a poorly-configured remote DNS will make it incommunicado;
      but it protects against a DNS-interception attack on it.

JH/04 Bug 1810: make continued-use of an open smtp transport connection
      non-noisy when a race steals the message being considered.

JH/05 If main configuration option tls_certificate is unset, generate a
      self-signed certificate for inbound TLS connections.

JH/06 Bug 165: hide more cases of password exposure - this time in expansions
      in rewrites and routers.

JH/07 Retire gnutls_require_mac et.al.  These were nonfunctional since 4.80
      and logged a warning sing 4.83; now they are a configuration file error.

JH/08 Bug 1836: Fix crash in VRFY handling when handed an unqualified name
      (lacking @domain).  Apply the same qualification processing as RCPT.

JH/09 Bug 1804: Avoid writing msglog files when in -bh or -bhc mode.

JH/10 Support ${sha256:} applied to a string (as well as the previous
      certificate).

JH/11 Cutthrough: avoid using the callout hints db on a verify callout when
      a cutthrough deliver is pending, as we always want to make a connection.
      This also avoids re-routing the message when later placing the cutthrough
      connection after a verify cache hit.
      Do not update it with the verify result either.

JH/12 Cutthrough: disable when verify option success_on_redirect is used, and
      when routing results in more than one destination address.

JH/13 Cutthrough: expand transport dkim_domain option when testing for dkim
      signing (which inhibits the cutthrough capability).  Previously only
      the presence of an option was tested; now an expansion evaluating as
      empty is permissible (obviously it should depend only on data available
      when the cutthrough connection is made).

JH/14 Fix logging of errors under PIPELINING.  Previously the log line giving
      the relevant preceding SMTP command did not note the pipelining mode.

JH/15 Fix counting of empty lines in $body_linecount and $message_linecount.
      Previously they were not counted.

JH/16 DANE: treat a TLSA lookup response having all non-TLSA RRs, the same
      as one having no matching records.  Previously we deferred the message
      that needed the lookup.

JH/17 Fakereject: previously logged as a normal message arrival "<="; now
      distinguished as "(=".

JH/18 Bug 1867: make the fail_defer_domains option on a dnslookup router work
      for missing MX records.  Previously it only worked for missing A records.

JH/19 Bug 1850: support Radius libraries that return REJECT_RC.

JH/20 Bug 1872: Ensure that acl_smtp_notquit is run when the connection drops
      after the data-go-ahead and data-ack.  Patch from Jason Betts.

JH/21 Bug 1846: Send DMARC forensic reports for reject and quarantine results,
      even for a "none" policy.  Patch from Tony Meyer.

JH/22 Fix continued use of a connection for further deliveries. If a port was
      specified by a router, it must also match for the delivery to be
      compatible.

JH/23 Bug 1874: fix continued use of a connection for further deliveries.
      When one of the recipients of a message was unsuitable for the connection
      (has no matching addresses), we lost track of needing to mark it
      deferred.  As a result mail would be lost.

JH/24 Bug 1832: Log EHLO response on getting conn-close response for HELO.

JH/25 Decoding ACL controls is now done using a binary search; the source code
      takes up less space and should be simpler to maintain.  Merge the ACL
      condition decode tables also, with similar effect.

JH/26 Fix problem with one_time used on a redirect router which returned the
      parent address unchanged.  A retry would see the parent address marked as
      delivered, so not attempt the (identical) child.  As a result mail would
      be lost.

JH/27 Fix a possible security hole, wherein a process operating with the Exim
      UID can gain a root shell.  Credit to http://www.halfdog.net/ for
      discovery and writeup.  Ubuntu bug 1580454; no bug raised against Exim
      itself :(

JH/28 Enable {spool,log} filesystem space and inode checks as default.
      Main config options check_{log,spool}_{inodes,space} are now
      100 inodes, 10MB unless set otherwise in the configuration.

JH/29 Fix the connection_reject log selector to apply to the connect ACL.
      Previously it only applied to the main-section connection policy
      options.

JH/30 Bug 1897: fix callouts connection fallback from TLS to cleartext.

PP/01 Changed default Diffie-Hellman parameters to be Exim-specific, created
      by me.  Added RFC7919 DH primes as an alternative.

PP/02 Unbreak build via pkg-config with new hash support when crypto headers
      are not in the system include path.

JH/31 Fix longstanding bug with aborted TLS server connection handling.  Under
      GnuTLS, when a session startup failed (eg because the client disconnected)
      Exim did stdio operations after fclose.  This was exposed by a recent
      change which nulled out the file handle after the fclose.

JH/32 Bug 1909: Fix OCSP proof verification for cases where the proof is
      signed directly by the cert-signing cert, rather than an intermediate
      OCSP-signing cert.  This is the model used by LetsEncrypt.

JH/33 Bug 1914: Ensure socket is nonblocking before draining after SMTP QUIT.

HS/01 Fix leak in verify callout under GnuTLS, about 3MB per recipient on
      an incoming connection.

HS/02 Bug 1802: Do not half-close the connection after sending a request
      to rspamd.

HS/03 Use "auto" as the default EC curve parameter. For OpenSSL < 1.0.2
      fallback to "prime256v1".

JH/34 SECURITY: Use proper copy of DATA command in error message.
      Could leak key material.  Remotely exploitable.  CVE-2016-9963.


Exim version 4.87
-----------------

JH/01 Bug 1664: Disable OCSP for GnuTLS library versions at/before 3.3.16
      and 3.4.4 - once the server is enabled to respond to an OCSP request
      it does even when not requested, resulting in a stapling non-aware
      client dropping the TLS connection.

TF/01 Code cleanup: Overhaul the debug_selector and log_selector machinery to
      support variable-length bit vectors. No functional change.

TF/02 Improve the consistency of logging incoming and outgoing interfaces.
      The I= interface field on outgoing lines is now after the H= remote
      host field, same as incoming lines. There is a separate
      outgoing_interface log selector which allows you to disable the
      outgoing I= field.

JH/02 Bug 728: Close logfiles after a daemon-process "exceptional" log write.
      If not running log_selector +smtp_connection the mainlog would be held
      open indefinitely after a "too many connections" event, including to a
      deleted file after a log rotate. Leave the per net connection logging
      leaving it open for efficiency as that will be quickly detected by the
      check on the next write.

HS/01 Bug 1671: Fix post transport crash.
      Processing the wait-<transport> messages could crash the delivery
      process if the message IDs didn't exist for some reason. When
      using 'split_spool_directory=yes' the construction of the spool
      file name failed already, exposing the same netto behaviour.

JH/03 Bug 425: Capture substrings in $regex1, $regex2 etc from regex &
      mime_regex ACL conditions.

JH/04 Bug 1686: When compiled with EXPERIMENTAL_DSN_INFO: Add extra information
      to DSN fail messages (bounces): remote IP, remote greeting, remote response
      to HELO, local diagnostic string.

JH/05 Downgrade message for a TLS-certificate-based authentication fail from
      log line to debug.  Even when configured with a tls authenticator many
      client connections are expected to not authenticate in this way, so
      an authenticate fail is not an error.

HS/02 Add the Exim version string to the process info.  This way exiwhat
      gives some more detail about the running daemon.

JH/06 Bug 1395: time-limit caching of DNS lookups, to the TTL value.  This may
      matter for fast-change records such as DNSBLs.

JH/07 Bug 1678: Always record an interface option value, if set,  as part of a
      retry record, even if constant.  There may be multiple transports with
      different interface settings and the retry behaviour needs to be kept
      distinct.

JH/08 Bug 1586: exiqgrep now refuses to run if there are unexpected arguments.

JH/09 Bug 1700: ignore space & tab embedded in base64 during decode.

JH/10 Bug 840: fix log_defer_output option of pipe transport

JH/11 Bug 830: use same host for all RCPTS of a message, even under
      hosts_randomize.  This matters a lot when combined with mua_wrapper.

JH/12 Bug 1706: percent and underbar characters are no longer escaped by the
      ${quote_pgsql:<string>} operator.

JH/13 Bug 1708: avoid misaligned access in cached lookup.

JH/14 Change header file name for freeradius-client.  Relevant if compiling
      with Radius support; from the Gentoo tree and checked under Fedora.

JH/15 Bug 1712: Introduce $prdr_requested flag variable

JH/16 Bug 1714: Permit an empty string as expansion result for transport
      option transport_filter, meaning no filtering.

JH/17 Bug 1713: Fix non-PDKIM_DEBUG build.  Patch from Jasen Betts.

JH/18 Bug 1709: When built with TLS support, the tls_advertise_hosts option now
      defaults to "*" (all hosts).  The variable is now available when not built
      with TLS, default unset, mainly to enable keeping the testsuite sane.
      If a server certificate is not supplied (via tls_certificate) an error is
      logged, and clients will find TLS connections fail on startup.  Presumably
      they will retry in-clear.
      Packagers of Exim are strongly encouraged to create a server certificate
      at installation time.

HS/03 Add -bP config_file as a synonym for -bP configure_file, for consistency
      with the $config_file variable.

JH/19 Two additional event types: msg:rcpt:defer and msg:rcpt:host:defer. Both
      in transport context, after the attempt, and per-recipient. The latter type
      is per host attempted.  The event data is the error message, and the errno
      information encodes the lookup type (A vs. MX) used for the (first) host,
      and the trailing two digits of the smtp 4xx response.

GF/01 Bug 1715: Fix for race condition in exicyclog, where exim could attempt
      to write to mainlog (or rejectlog, paniclog) in the window between file
      creation and permissions/ownership being changed. Particularly affects
      installations where exicyclog is run as root, rather than exim user;
      result is that the running daemon panics and dies.

JH/20 Bug 1701: For MySQL lookups, support MySQL config file option group names.

JH/21 Bug 1720: Add support for priority groups and weighted-random proxy
      selection for the EXPERIMENTAL_SOCKS feature, via new per-proxy options
      "pri" and "weight".  Note that the previous implicit priority given by the
      list order is no longer honoured.

JH/22 Bugs 963, 1721: Fix some corner cases in message body canonicalization
      for DKIM processing.

JH/23 Move SOCKS5 support from Experimental to mainline, enabled for a build
      by defining SUPPORT_SOCKS.

JH/26 Move PROXY support from Experimental to mainline, enabled for a build
      by defining SUPPORT_PROXY.  Note that the proxy_required_hosts option
      is renamed to hosts_proxy, and the proxy_{host,target}_{address,port}.
      variables are renamed to proxy_{local,external}_{address,port}.

JH/27 Move Internationalisation support from Experimental to mainline, enabled
      for a build by defining SUPPORT_I18N

JH/28 Bug 1745: Fix redis lookups to handle (quoted) spaces embedded in parts
      of the query string, and make ${quote_redis:} do that quoting.

JH/29 Move Events support from Experimental to mainline, enabled by default
      and removable for a build by defining DISABLE_EVENT.

JH/30 Updated DANE implementation code to current from Viktor Dukhovni.

JH/31 Fix bug with hosts_connection_nolog and named-lists which were wrongly
      cached by the daemon.

JH/32 Move Redis support from Experimental to mainline, enabled for a build
      by defining LOOKUP_REDIS. The libhiredis library is required.

JH/33 Bug 1748: Permit ACL dnslists= condition in non-smtp ACLs if explicit
      keys are given for lookup.

JH/34 Bug 1192: replace the embedded copy of PolarSSL RSA routines in the DKIM
      support, by using OpenSSL or GnuTLS library ones.  This means DKIM is
      only supported when built with TLS support.  The PolarSSL SHA routines
      are still used when the TLS library is too old for convenient support.

JH/35 Require SINGLE_DH_USE by default in OpenSSL (main config option
      openssl_options), for security.  OpenSSL forces this from version 1.1.0
      server-side so match that on older versions.

JH/36 Bug 1778: longstanding bug in memory use by the ${run } expansion: A fresh
      allocation for $value could be released as the expansion processing
      concluded, but leaving the global pointer active for it.

JH/37 Bug 1769: Permit a VRFY ACL to override the default 252 response,
      and to use the domains and local_parts ACL conditions.

JH/38 Fix cutthrough bug with body lines having a single dot. The dot was
      incorrectly not doubled on cutthrough transmission, hence seen as a
      body-termination at the receiving system - resulting in truncated mails.
      Commonly the sender saw a TCP-level error, and retransmitted the message
      via the normal store-and-forward channel. This could result in duplicates
      received - but deduplicating mailstores were liable to retain only the
      initial truncated version.

JH/39 Bug 1781: Fix use of DKIM private-keys having trailing '=' in the base-64.

JH/40 Fix crash in queryprogram router when compiled with EXPERIMENTAL_SRS.

JH/41 Bug 1792: Fix selection of headers to sign for DKIM: bottom-up.  While
      we're in there, support oversigning also; bug 1309.

JH/42 Bug 1796: Fix error logged on a malware scanner connection failure.

HS/04 Add support for keep_environment and add_environment options.

JH/43 Tidy coding issues detected by gcc --fsanitize=undefined.  Some remain;
      either intentional arithmetic overflow during PRNG, or testing config-
      induced overflows.

JH/44 Bug 1800: The combination of a -bhc commandline option and cutthrough
      delivery resulted in actual delivery.  Cancel cutthrough before DATA
      stage.

JH/45 Fix cutthrough, when connection not opened by verify and target hard-
      rejects a recipient: pass the reject to the originator.

JH/46 Multiple issues raised by Coverity. Some were obvious or plausible bugs.
      Many were false-positives and ignorable, but it's worth fixing the
      former class.

JH/47 Fix build on HP-UX and older Solaris, which need (un)setenv now also
      for the new environment-manipulation done at startup.  Move the routines
      from being local to tls.c to being global via the os.c file.

JH/48 Bug 1807: Fix ${extract } for the numeric/3-string case. While preparsing
      an extract embedded as result-arg for a map, the first arg for extract
      is unavailable so we cannot tell if this is a numbered or keyed
      extraction.  Accept either.


Exim version 4.86
-----------------

JH/01 Bug 1545: The smtp transport option "retry_include_ip_address" is now
      expanded.

JH/02 The smtp transport option "multi_domain" is now expanded.

JH/03 The smtp transport now requests PRDR by default, if the server offers
      it.

JH/04 Certificate name checking on server certificates, when exim is a client,
      is now done by default.  The transport option tls_verify_cert_hostnames
      can be used to disable this per-host.  The build option
      EXPERIMENTAL_CERTNAMES is withdrawn.

JH/05 The value of the tls_verify_certificates smtp transport and main options
      default to the word "system" to access the system default CA bundle.
      For GnuTLS, only version 3.0.20 or later.

JH/06 Verification of the server certificate for a TLS connection is now tried
      (but not required) by default.  The verification status is now logged by
      default, for both outbound TLS and client-certificate supplying inbound
      TLS connections

JH/07 Changed the default rfc1413 lookup settings to disable calls.  Few
      sites use this now.

JH/08 The EXPERIMENTAL_DSN compile option is no longer needed; all Delivery
      Status Notification (bounce) messages are now MIME format per RFC 3464.
      Support for RFC 3461 DSN options NOTIFY,ENVID,RET,ORCPT can be advertised
      under the control of the dsn_advertise_hosts option, and routers may
      have a dsn_lasthop option.

JH/09 A timeout of 2 minutes is now applied to all malware scanner types by
      default, modifiable by a malware= option.  The list separator for
      the options can now be changed in the usual way.  Bug 68.

JH/10 The smtp_receive_timeout main option is now expanded before use.

JH/11 The incoming_interface log option now also enables logging of the
      local interface on delivery outgoing connections.

JH/12 The cutthrough-routing facility now supports multi-recipient mails,
      if the interface and destination host and port all match.

JH/13 Bug 344: The verify = reverse_host_lookup ACL condition now accepts a
      /defer_ok option.

JH/14 Bug 1573: The spam= ACL condition now additionally supports Rspamd.
      Patch from Andrew Lewis.

JH/15 Bug 670: The spamd_address main option (for the spam= ACL condition)
      now supports optional time-restrictions, weighting, and priority
      modifiers per server.  Patch originally by <rommer@active.by>.

JH/16 The spamd_address main option now supports a mixed list of local
      and remote servers.  Remote servers can be IPv6 addresses, and
      specify a port-range.

JH/17 Bug 68: The spamd_address main option now supports an optional
      timeout value per server.

JH/18 Bug 1581: Router and transport options headers_add/remove can
      now have the list separator specified.

JH/19 Bug 392: spamd_address, and clamd av_scanner, now support retry
      option values.

JH/20 Bug 1571: Ensure that $tls_in_peerdn is set, when verification fails
      under OpenSSL.

JH/21 Support for the A6 type of dns record is withdrawn.

JH/22 Bug 608: The result of a QUIT or not-QUIT toplevel ACL now matters
      rather than the verbs used.

JH/23 Bug 1572: Increase limit on SMTP confirmation message copy size
      from 255 to 1024 chars.

JH/24 Verification callouts now attempt to use TLS by default.

HS/01 DNSSEC options (dnssec_require_domains, dnssec_request_domains)
      are generic router options now. The defaults didn't change.

JH/25 Bug 466: Add RFC2322 support for MIME attachment filenames.
      Original patch from Alexander Shikoff, worked over by JH.

HS/02 Bug 1575: exigrep falls back to autodetection of compressed
      files if ZCAT_COMMAND is not executable.

JH/26 Bug 1539: Add timeout/retry options on dnsdb lookups.

JH/27 Bug 286: Support SOA lookup in dnsdb lookups.

JH/28 Bug 1588: Do not use the A lookup following an AAAA for setting the FQDN.
      Normally benign, it bites when the pair was led to by a CNAME;
      modern usage is to not canonicalize the domain to a CNAME target
      (and we were inconsistent anyway for A-only vs AAAA+A).

JH/29 Bug 1632: Removed the word "rejected" from line logged for ACL discards.

JH/30 Check the forward DNS lookup for DNSSEC, in addition to the reverse,
      when evaluating $sender_host_dnssec.

JH/31 Check the HELO verification lookup for DNSSEC, adding new
      $sender_helo_dnssec variable.

JH/32 Bug 1397: Enable ECDHE on OpenSSL, just the NIST P-256 curve.

JH/33 Bug 1346: Note MAIL cmd seen in -bS batch, to avoid smtp_no_mail log.

JH/34 Bug 1648: Fix a memory leak seen with "mailq" and large queues.

JH/35 Bug 1642: Fix support of $spam_ variables at delivery time.  Was
      documented as working, but never had.  Support all but $spam_report.

JH/36 Bug 1659: Guard checking of input smtp commands again pseudo-command
      added for tls authenticator.

HS/03 Add perl_taintmode main config option


Exim version 4.85
-----------------

TL/01 When running the test suite, the README says that variables such as
      no_msglog_check are global and can be placed anywhere in a specific
      test's script, however it was observed that placement needed to be near
      the beginning for it to behave that way. Changed the runtest perl
      script to read through the entire script once to detect and set these
      variables, reset to the beginning of the script, and then run through
      the script parsing/test process like normal.

TL/02 The BSD's have an arc4random API. One of the functions to induce
      adding randomness was arc4random_stir(), but it has been removed in
      OpenBSD 5.5. Detect this OpenBSD version and skip calling this
      function when detected.

JH/01 Expand the EXPERIMENTAL_TPDA feature.  Several different events now
      cause callback expansion.

TL/03 Bugzilla 1518: Clarify "condition" processing in routers; that
      syntax errors in an expansion can be treated as a string instead of
      logging or causing an error, due to the internal use of bool_lax
      instead of bool when processing it.

JH/02 Add EXPERIMENTAL_DANE, allowing for using the DNS as trust-anchor for
      server certificates when making smtp deliveries.

JH/03 Support secondary-separator specifier for MX, SRV, TLSA lookups.

JH/04 Add ${sort {list}{condition}{extractor}} expansion item.

TL/04 Bugzilla 1216: Add -M (related messages) option to exigrep.

TL/05 GitHub Issue 18: Adjust logic testing for true/false in redis lookups.
      Merged patch from Sebastian Wiedenroth.

JH/05 Fix results-pipe from transport process.  Several recipients, combined
      with certificate use, exposed issues where response data items split
      over buffer boundaries were not parsed properly.  This eventually
      resulted in duplicates being sent.  This issue only became common enough
      to notice due to the introduction of connection certificate information,
      the item size being so much larger.  Found and fixed by Wolfgang Breyha.

JH/06 Bug 1533: Fix truncation of items in headers_remove lists.  A fixed
      size buffer was used, resulting in syntax errors when an expansion
      exceeded it.

JH/07 Add support for directories of certificates when compiled with a GnuTLS
      version 3.3.6 or later.

JH/08 Rename the TPDA experimental facility to Event Actions.  The #ifdef
      is EXPERIMENTAL_EVENT, the main-configuration and transport options
      both become "event_action", the variables become $event_name, $event_data
      and $event_defer_errno.  There is a new variable $verify_mode, usable in
      routers, transports and related events.  The tls:cert event is now also
      raised for inbound connections, if the main configuration event_action
      option is defined.

TL/06 In test suite, disable OCSP for old versions of openssl which contained
      early OCSP support, but no stapling (appears to be less than 1.0.0).

JH/09 When compiled with OpenSSL and EXPERIMENTAL_CERTNAMES, the checks on
      server certificate names available under the smtp transport option
      "tls_verify_cert_hostname" now do not permit multi-component wildcard
      matches.

JH/10 Time-related extraction expansions from certificates now use the main
      option "timezone" setting for output formatting, and are consistent
      between OpenSSL and GnuTLS compilations.  Bug 1541.

JH/11 Fix a crash in mime ACL when meeting a zero-length, quoted or RFC2047-
      encoded parameter in the incoming message.  Bug 1558.

JH/12 Bug 1527: Autogrow buffer used in reading spool files.  Since they now
      include certificate info, eximon was claiming there were spoolfile
      syntax errors.

JH/13 Bug 1521: Fix ldap lookup for single-attr request, multiple-attr return.

JH/14 Log delivery-related information more consistently, using the sequence
      "H=<name> [<ip>]" wherever possible.

TL/07 Bug 1547: Omit RFCs from release. Draft and RFCs have licenses which
      are problematic for Debian distribution, omit them from the release
      tarball.

JH/15 Updates and fixes to the EXPERIMENTAL_DSN feature.

JH/16 Fix string representation of time values on 64bit time_t architectures.
      Bug 1561.

JH/17 Fix a null-indirection in certextract expansions when a nondefault
      output list separator was used.


Exim version 4.84
-----------------
TL/01 Bugzilla 1506: Re-add a 'return NULL' to silence complaints from static
      checkers that were complaining about end of non-void function with no
      return.

JH/01 Bug 1513: Fix parsing of quoted parameter values in MIME headers.
      This was a regression introduced in 4.83 by another bugfix.

JH/02 Fix broken compilation when EXPERIMENTAL_DSN is enabled.

TL/02 Bug 1509: Fix exipick for enhanced spoolfile specification used when
      EXPERIMENTAL_DSN is enabled.  Fix from Wolfgang Breyha.


Exim version 4.83
-----------------

TF/01 Correctly close the server side of TLS when forking for delivery.

      When a message was received over SMTP with TLS, Exim failed to clear up
      the incoming connection properly after forking off the child process to
      deliver the message. In some situations the subsequent outgoing
      delivery connection happened to have the same fd number as the incoming
      connection previously had. Exim would try to use TLS and fail, logging
      a "Bad file descriptor" error.

TF/02 Portability fix for building lookup modules on Solaris when the xpg4
      utilities have not been installed.

JH/01 Fix memory-handling in use of acl as a conditional; avoid free of
      temporary space as the ACL may create new global variables.

TL/01 LDAP support uses per connection or global context settings, depending
      upon the detected version of the libraries at build time.

TL/02 Experimental Proxy Protocol support: allows a proxied SMTP connection
      to extract and use the src ip:port in logging and expansions as if it
      were a direct connection from the outside internet. PPv2 support was
      updated based on HAProxy spec change in May 2014.

JH/02 Add ${listextract {number}{list}{success}{fail}}.

TL/03 Bugzilla 1433: Fix DMARC SEGV with specific From header contents.
      Properly escape header and check for NULL return.

PP/01 Continue incomplete 4.82 PP/19 by fixing docs too: use dns_dnssec_ok
      not dns_use_dnssec.

JH/03 Bugzilla 1157: support log_selector smtp_confirmation for lmtp.

TL/04 Add verify = header_names_ascii check to reject email with non-ASCII
      characters in header names, implemented as a verify condition.
      Contributed by Michael Fischer v. Mollard.

TL/05 Rename SPF condition results err_perm and err_temp to standardized
      results permerror and temperror.  Previous values are deprecated but
      still accepted.  In a future release, err_perm and err_temp will be
      completely removed, which will be a backward incompatibility if the
      ACL tests for either of these two old results. Patch contributed by
      user bes-internal on the mailing list.

JH/04 Add ${utf8clean:} operator. Contributed by Alex Rau.

JH/05 Bugzilla 305: Log incoming-TLS details on rejects, subject to log
      selectors, in both main and reject logs.

JH/06 Log outbound-TLS and port details, subject to log selectors, for a
      failed delivery.

JH/07 Add malware type "sock" for talking to simple daemon.

JH/08 Bugzilla 1371: Add tls_{,try_}verify_hosts to smtp transport.

JH/09 Bugzilla 1431: Support (with limitations) headers_add/headers_remove in
      routers/transports under cutthrough routing.

JH/10 Bugzilla 1005: ACL "condition =" should accept values which are negative
      numbers.  Touch up "bool" conditional to keep the same definition.

TL/06 Remove duplicated language in spec file from 4.82 TL/16.

JH/11 Add dnsdb tlsa lookup.  From Todd Lyons.

JH/12 Expand items in router/transport headers_add or headers_remove lists
      individually rather than the list as a whole.  Bug 1452.

      Required for reasonable handling of multiple headers_ options when
      they may be empty; requires that headers_remove items with embedded
      colons must have them doubled (or the list-separator changed).

TL/07 Add new dmarc expansion variable $dmarc_domain_policy to directly
      view the policy declared in the DMARC record. Currently, $dmarc_status
      is a combined value of both the record presence and the result of the
      analysis.

JH/13 Fix handling of $tls_cipher et.al. in (non-verify) transport.  Bug 1455.

JH/14 New options dnssec_request_domains, dnssec_require_domains on the
      dnslookup router and the smtp transport (applying to the forward
      lookup).

TL/08 Bugzilla 1453: New LDAP "SERVERS=" option allows admin to override list
      of ldap servers used for a specific lookup.  Patch provided by Heiko
      Schlichting.

JH/18 New options dnssec_lax, dnssec_strict on dnsdb lookups.
      New variable $lookup_dnssec_authenticated for observability.

TL/09 Bugzilla 609: Add -C option to exiqgrep, specify which exim.conf to use.
      Patch submitted by Lars Timman.

JH/19 EXPERIMENTAL_OCSP support under GnuTLS.  Bug 1459.

TL/10 Bugzilla 1454: New -oMm option to pass message reference to Exim.
      Requires trusted mode and valid format message id, aborts otherwise.
      Patch contributed by Heiko Schlichting.

JH/20 New expansion variables tls_(in,out)_(our,peer)cert, and expansion item
      certextract with support for various fields.  Bug 1358.

JH/21 Observability of OCSP via variables tls_(in,out)_ocsp.  Stapling
      is requested by default, modifiable by smtp transport option
      hosts_request_ocsp.

JH/22 Expansion operators ${md5:string} and ${sha1:string} can now
      operate on certificate variables to give certificate fingerprints
      Also new ${sha256:cert_variable}.

JH/23 The PRDR feature is moved from being Experimental into the mainline.

TL/11 Bug 1119: fix memory allocation in string_printing2().  Patch from
      Christian Aistleitner.

JH/24 The OCSP stapling feature is moved from Experimental into the mainline.

TL/12 Bug 1444: Fix improper \r\n sequence handling when writing spool
      file.  Patch from Wolfgang Breyha.

JH/25 Expand the coverage of the delivery $host and $host_address to
      client authenticators run in verify callout.  Bug 1476.

JH/26 Port service names are now accepted for tls_on_connect_ports, to
      align with daemon_smtp_ports.  Bug 72.

TF/03 Fix udpsend. The ip_connectedsocket() function's socket type
      support and error reporting did not work properly.

TL/13 Bug 1495: Exiqgrep check if -C config file specified on cli exists
      and is readable.  Patch from Andrew Colin Kissa.

TL/14 Enhance documentation of ${run expansion and how it parses the
      commandline after expansion, particularly in the case when an
      unquoted variable expansion results in an empty value.

JH/27 The TLS SNI feature was broken in 4.82.  Fix it.

PP/02 Fix internal collision of T_APL on systems which support RFC3123
      by renaming away from it.  Addresses GH issue 15, reported by
      Jasper Wallace.

JH/28 Fix parsing of MIME headers for parameters with quoted semicolons.

TL/15 SECURITY: prevent double expansion in math comparison functions
      (can expand unsanitized data). Not remotely exploitable.
      CVE-2014-2972


Exim version 4.82
-----------------

PP/01 Add -bI: framework, and -bI:sieve for querying sieve capabilities.

PP/02 Make -n do something, by making it not do something.
      When combined with -bP, the name of an option is not output.

PP/03 Added tls_dh_min_bits SMTP transport driver option, only honoured
      by GnuTLS.

PP/04 First step towards DNSSEC, provide $sender_host_dnssec for
      $sender_host_name and config options to manage this, and basic check
      routines.

PP/05 DSCP support for outbound connections and control modifier for inbound.

PP/06 Cyrus SASL: set local and remote IP;port properties for driver.
      (Only plugin which currently uses this is kerberos4, which nobody should
      be using, but we should make it available and other future plugins might
      conceivably use it, even though it would break NAT; stuff *should* be
      using channel bindings instead).

PP/07 Handle "exim -L <tag>" to indicate to use syslog with tag as the process
      name; added for Sendmail compatibility; requires admin caller.
      Handle -G as equivalent to "control = suppress_local_fixups" (we used to
      just ignore it); requires trusted caller.
      Also parse but ignore: -Ac -Am -X<logfile>
      Bugzilla 1117.

TL/01 Bugzilla 1258 - Refactor MAIL FROM optional args processing.

TL/02 Add +smtp_confirmation as a default logging option.

TL/03 Bugzilla 198 - Implement remove_header ACL modifier.
      Patch by Magnus Holmgren from 2007-02-20.

TL/04 Bugzilla 1281 - Spec typo.
      Bugzilla 1283 - Spec typo.
      Bugzilla 1290 - Spec grammar fixes.

TL/05 Bugzilla 1285 - Spec omission, fix docbook errors for spec.txt creation.

TL/06 Add Experimental DMARC support using libopendmarc libraries.

TL/07 Fix an out of order global option causing a segfault.  Reported to dev
      mailing list by by Dmitry Isaikin.

JH/01 Bugzilla 1201 & 304 - New cutthrough-delivery feature, with TLS support.

JH/02 Support "G" suffix to numbers in ${if comparisons.

PP/08 Handle smtp transport tls_sni option forced-fail for OpenSSL.

NM/01 Bugzilla 1197 - Spec typo
      Bugzilla 1196 - Spec examples corrections

JH/03 Add expansion operators ${listnamed:name} and ${listcount:string}

PP/09 Add gnutls_allow_auto_pkcs11 option (was originally called
      gnutls_enable_pkcs11, but renamed to more accurately indicate its
      function.

PP/10 Let Linux makefile inherit CFLAGS/CFLAGS_DYNAMIC.
      Pulled from Debian 30_dontoverridecflags.dpatch by Andreas Metzler.

JH/04 Add expansion item ${acl {name}{arg}...}, expansion condition
      "acl {{name}{arg}...}", and optional args on acl condition
      "acl = name arg..."

JH/05 Permit multiple router/transport headers_add/remove lines.

JH/06 Add dnsdb pseudo-lookup "a+" to do an "aaaa" + "a" combination.

JH/07 Avoid using a waiting database for a single-message-only transport.
      Performance patch from Paul Fisher.  Bugzilla 1262.

JH/08 Strip leading/trailing newlines from add_header ACL modifier data.
      Bugzilla 884.

JH/09 Add $headers_added variable, with content from use of ACL modifier
      add_header (but not yet added to the message).  Bugzilla 199.

JH/10 Add 8bitmime log_selector, for 8bitmime status on the received line.
      Pulled from Bugzilla 817 by Wolfgang Breyha.

PP/11 SECURITY: protect DKIM DNS decoding from remote exploit.
      CVE-2012-5671
      (nb: this is the same fix as in Exim 4.80.1)

JH/11 Add A= logging on delivery lines, and a client_set_id option on
      authenticators.

JH/12 Add optional authenticated_sender logging to A= and a log_selector
      for control.

PP/12 Unbreak server_set_id for NTLM/SPA auth, broken by 4.80 PP/29.

PP/13 Dovecot auth: log better reason to rejectlog if Dovecot did not
      advertise SMTP AUTH mechanism to us, instead of a generic
      protocol violation error.  Also, make Exim more robust to bad
      data from the Dovecot auth socket.

TF/01 Fix ultimate retry timeouts for intermittently deliverable recipients.

      When a queue runner is handling a message, Exim first routes the
      recipient addresses, during which it prunes them based on the retry
      hints database. After that it attempts to deliver the message to
      any remaining recipients. It then updates the hints database using
      the retry rules.

      So if a recipient address works intermittently, it can get repeatedly
      deferred at routing time. The retry hints record remains fresh so the
      address never reaches the final cutoff time.

      This is a fairly common occurrence when a user is bumping up against
      their storage quota. Exim had some logic in its local delivery code
      to deal with this. However it did not apply to per-recipient defers
      in remote deliveries, e.g. over LMTP to a separate IMAP message store.

      This change adds a proper retry rule check during routing so that the
      final cutoff time is checked against the message's age. We only do
      this check if there is an address retry record and there is not a
      domain retry record; this implies that previous attempts to handle
      the address had the retry_use_local_parts option turned on. We use
      this as an approximation for the destination being like a local
      delivery, as in LMTP.

      I suspect this new check makes the old local delivery cutoff check
      redundant, but I have not verified this so I left the code in place.

TF/02 Correct gecos expansion when From: is a prefix of the username.

      Test 0254 submits a message to Exim with the header

        Resent-From: f

      When I ran the test suite under the user fanf2, Exim expanded
      the header to contain my full name, whereas it should have added
      a Resent-Sender: header. It erroneously treats any prefix of the
      username as equal to the username.

      This change corrects that bug.

GF/01 DCC debug and logging tidyup
      Error conditions log to paniclog rather than rejectlog.
      Debug lines prefixed by "DCC: " to remove any ambiguity.

TF/03 Avoid unnecessary rebuilds of lookup-related code.

PP/14 Fix OCSP reinitialisation in SNI handling for Exim/TLS as server.
      Bug spotted by Jeremy Harris; was flawed since initial commit.
      Would have resulted in OCSP responses post-SNI triggering an Exim
      NULL dereference and crash.

JH/13 Add $router_name and $transport_name variables.  Bugzilla 308.

PP/15 Define SIOCGIFCONF_GIVES_ADDR for GNU Hurd.
      Bug detection, analysis and fix by Samuel Thibault.
      Bugzilla 1331, Debian bug #698092.

SC/01 Update eximstats to watch out for senders sending 'HELO [IpAddr]'

JH/14 SMTP PRDR (http://www.eric-a-hall.com/specs/draft-hall-prdr-00.txt).
      Server implementation by Todd Lyons, client by JH.
      Only enabled when compiled with EXPERIMENTAL_PRDR.  A new
      config variable "prdr_enable" controls whether the server
      advertises the facility.  If the client requests PRDR a new
      acl_data_smtp_prdr ACL is called once for each recipient, after
      the body content is received and before the acl_smtp_data ACL.
      The client is controlled by both of: a hosts_try_prdr option
      on the smtp transport, and the server advertisement.
      Default client logging of deliveries and rejections involving
      PRDR are flagged with the string "PRDR".

PP/16 Fix problems caused by timeouts during quit ACLs trying to double
      fclose().  Diagnosis by Todd Lyons.

PP/17 Update configure.default to handle IPv6 localhost better.
      Patch by Alain Williams (plus minor tweaks).
      Bugzilla 880.

PP/18 OpenSSL made graceful with empty tls_verify_certificates setting.
      This is now consistent with GnuTLS, and is now documented: the
      previous undocumented portable approach to treating the option as
      unset was to force an expansion failure.  That still works, and
      an empty string is now equivalent.

PP/19 Renamed DNSSEC-enabling option to "dns_dnssec_ok", to make it
      clearer that Exim is using the DO (DNSSEC OK) EDNS0 resolver flag,
      not performing validation itself.

PP/20 Added force_command boolean option to pipe transport.
      Patch from Nick Koston, of cPanel Inc.

JH/15 AUTH support on callouts (and hence cutthrough-deliveries).
      Bugzilla 321, 823.

TF/04 Added udpsend ACL modifier and hexquote expansion operator

PP/21 Fix eximon continuous updating with timestamped log-files.
      Broken in a format-string cleanup in 4.80, missed when I repaired the
      other false fix of the same issue.
      Report and fix from Heiko Schlichting.
      Bugzilla 1363.

PP/22 Guard LDAP TLS usage against Solaris LDAP variant.
      Report from Prashanth Katuri.

PP/23 Support safari_ecdhe_ecdsa_bug for openssl_options.
      It's SecureTransport, so affects any MacOS clients which use the
      system-integrated TLS libraries, including email clients.

PP/24 Fix segfault from trying to fprintf() to a NULL stdio FILE* if
      using a MIME ACL for non-SMTP local injection.
      Report and assistance in diagnosis by Warren Baker.

TL/08 Adjust exiqgrep to be case-insensitive for sender/receiver.

JH/16 Fix comparisons for 64b.  Bugzilla 1385.

TL/09 Add expansion variable $authenticated_fail_id to keep track of
      last id that failed so it may be referenced in subsequent ACL's.

TL/10 Bugzilla 1375 - Prevent TLS rebinding in ldap. Patch provided by
      Alexander Miroch.

TL/11 Bugzilla 1382 - Option ldap_require_cert overrides start_tls
      ldap library initialization, allowing self-signed CA's to be
      used. Also properly sets require_cert option later in code by
      using NULL (global ldap config) instead of ldap handle (per
      session). Bug diagnosis and testing by alxgomz.

TL/12 Enhanced documentation in the ratelimit.pl script provided in
      the src/util/ subdirectory.

TL/13 Bug 1031 - Imported transport SQL logging patch from Axel Rau
      renamed to Transport Post Delivery Action by Jeremy Harris, as
      EXPERIMENTAL_TPDA.

TL/14 Bugzilla 1217 - Redis lookup support has been added. It is only enabled
      when Exim is compiled with EXPERIMENTAL_REDIS. A new config variable
      redis_servers = needs to be configured which will be used by the redis
      lookup.  Patch from Warren Baker, of The Packet Hub.

TL/15 Fix exiqsumm summary for corner case. Patch provided by Richard Hall.

TL/16 Bugzilla 1289 - Clarify host/ip processing when have errors looking up a
      hostname or reverse DNS when processing a host list. Used suggestions
      from multiple comments on this bug.

TL/17 Bugzilla 1057 - Multiple clamd TCP targets patch from Mark Zealey.

TL/18 Had previously added a -CONTINUE option to runtest in the test suite.
      Missed a few lines, added it to make the runtest require no keyboard
      interaction.

TL/19 Bugzilla 1402 - Test 533 fails if any part of the path to the test suite
      contains upper case chars. Make router use caseful_local_part.

TL/20 Bugzilla 1400 - Add AVOID_GNUTLS_PKCS11 build option. Allows GnuTLS
      support when GnuTLS has been built with p11-kit.


Exim version 4.80.1
-------------------

PP/01 SECURITY: protect DKIM DNS decoding from remote exploit.
      CVE-2012-5671
      This, or similar/improved, will also be change PP/11 of 4.82.


Exim version 4.80
-----------------

PP/01 Handle short writes when writing local log-files.
      In practice, only affects FreeBSD (8 onwards).
      Bugzilla 1053, with thanks to Dmitry Isaikin.

NM/01 Bugzilla 949 - Documentation tweak

NM/02 Bugzilla 1093 - eximstats DATA reject detection regexps
      improved.

NM/03 Bugzilla 1169 - primary_hostname spelling was incorrect in docs.

PP/02 Implemented gsasl authenticator.

PP/03 Implemented heimdal_gssapi authenticator with "server_keytab" option.

PP/04 Local/Makefile support for (AUTH|LOOKUP)_*_PC=foo to use
      `pkg-config foo` for cflags/libs.

PP/05 Swapped $auth1/$auth2 for gsasl GSSAPI mechanism, to be more consistent
      with rest of GSASL and with heimdal_gssapi.

PP/06 Local/Makefile support for USE_(GNUTLS|OPENSSL)_PC=foo to use
      `pkg-config foo` for cflags/libs for the TLS implementation.

PP/07 New expansion variable $tls_bits; Cyrus SASL server connection
      properties get this fed in as external SSF.  A number of robustness
      and debugging improvements to the cyrus_sasl authenticator.

PP/08 cyrus_sasl server now expands the server_realm option.

PP/09 Bugzilla 1214 - Log authentication information in reject log.
      Patch by Jeremy Harris.

PP/10 Added dbmjz lookup type.

PP/11 Let heimdal_gssapi authenticator take a SASL message without an authzid.

PP/12 MAIL args handles TAB as well as SP, for better interop with
      non-compliant senders.
      Analysis and variant patch by Todd Lyons.

NM/04 Bugzilla 1237 - fix cases where printf format usage not indicated
      Bug report from Lars Müller <lars@samba.org> (via SUSE),
      Patch from Dirk Mueller <dmueller@suse.com>

PP/13 tls_peerdn now print-escaped for spool files.
      Observed some $tls_peerdn in wild which contained \n, which resulted
      in spool file corruption.

PP/14 TLS fixes for OpenSSL: support TLS 1.1 & 1.2; new "openssl_options"
      values; set SSL_MODE_AUTO_RETRY so that OpenSSL will retry a read
      or write after TLS renegotiation, which otherwise led to messages
      "Got SSL error 2".

TK/01 Bugzilla 1239 - fix DKIM verification when signature was not inserted
      as a tracking header (ie: a signed header comes before the signature).
      Patch from Wolfgang Breyha.

JH/01 Bugzilla 660 - Multi-valued attributes from ldap now parseable as a
      comma-sep list; embedded commas doubled.

JH/02 Refactored ACL "verify =" logic to table-driven dispatch.

PP/15 LDAP: Check for errors of TLS initialisation, to give correct
      diagnostics.
      Report and patch from Dmitry Banschikov.

PP/16 Removed "dont_insert_empty_fragments" from "openssl_options".
      Removed SSL_clear() after SSL_new() which led to protocol negotiation
      failures.  We appear to now support TLS1.1+ with Exim.

PP/17 OpenSSL: new expansion var $tls_sni, which if used in tls_certificate
      lets Exim select keys and certificates based upon TLS SNI from client.
      Also option tls_sni on SMTP Transports.  Also clear $tls_bits correctly
      before an outbound SMTP session.  New log_selector, +tls_sni.

PP/18 Bugzilla 1122 - check localhost_number expansion for failure, avoid
      NULL dereference.  Report and patch from Alun Jones.

PP/19 DNS resolver init changes for NetBSD compatibility.  (Risk of breakage
      on less well tested platforms).  Obviates NetBSD pkgsrc patch-ac.
      Not seeing resolver debug output on NetBSD, but suspect this is a
      resolver implementation change.

PP/20 Revert part of NM/04, it broke log_path containing %D expansions.
      Left warnings.  Added "eximon gdb" invocation mode.

PP/21 Defaulting "accept_8bitmime" to true, not false.

PP/22 Added -bw for inetd wait mode support.

PP/23 Added PCRE_CONFIG=yes support to Makefile for using pcre-config to
      locate the relevant includes and libraries.  Made this the default.

PP/24 Fixed headers_only on smtp transports (was not sending trailing dot).
      Bugzilla 1246, report and most of solution from Tomasz Kusy.

JH/03 ${eval } now uses 64-bit and supports a "g" suffix (like to "k" and "m").
      This may cause build issues on older platforms.

PP/25 Revamped GnuTLS support, passing tls_require_ciphers to
      gnutls_priority_init, ignoring Exim options gnutls_require_kx,
      gnutls_require_mac & gnutls_require_protocols (no longer supported).
      Added SNI support via GnuTLS too.
      Made ${randint:..} supplier available, if using not-too-old GnuTLS.

PP/26 Added EXPERIMENTAL_OCSP for OpenSSL.

PP/27 Applied dnsdb SPF support patch from Janne Snabb.
      Applied second patch from Janne, implementing suggestion to default
      multiple-strings-in-record handling to match SPF spec.

JH/04 Added expansion variable $tod_epoch_l for a higher-precision time.

PP/28 Fix DCC dcc_header content corruption (stack memory referenced,
      read-only, out of scope).
      Patch from Wolfgang Breyha, report from Stuart Northfield.

PP/29 Fix three issues highlighted by clang analyser static analysis.
      Only crash-plausible issue would require the Cambridge-specific
      iplookup router and a misconfiguration.
      Report from Marcin Mirosław.

PP/30 Another attempt to deal with PCRE_PRERELEASE, this one less buggy.

PP/31 %D in printf continues to cause issues (-Wformat=security), so for
      now guard some of the printf checks behind WANT_DEEPER_PRINTF_CHECKS.
      As part of this, removing so much warning spew let me fix some minor
      real issues in debug logging.

PP/32 GnuTLS was always using default tls_require_ciphers, due to a missing
      assignment on my part.  Fixed.

PP/33 Added tls_dh_max_bits option, defaulting to current hard-coded limit
      of NSS, for GnuTLS/NSS interop.  Problem root cause diagnosis by
      Janne Snabb (who went above and beyond: thank you).

PP/34 Validate tls_require_ciphers on startup, since debugging an invalid
      string otherwise requires a connection and a bunch more work and it's
      relatively easy to get wrong.  Should also expose TLS library linkage
      problems.

PP/35 Pull in <features.h> on Linux, for some portability edge-cases of
      64-bit ${eval} (JH/03).

PP/36 Define _GNU_SOURCE in exim.h; it's needed for some releases of
      GNU libc to support some of the 64-bit stuff, should not lead to
      conflicts.  Defined before os.h is pulled in, so if a given platform
      needs to override this, it can.

PP/37 Unbreak Cyrus SASL auth: SSF retrieval was incorrect, Exim thought
      protection layer was required, which is not implemented.
      Bugzilla 1254, patch from Wolfgang Breyha.

PP/38 Overhaul DH prime handling, supply RFC-specified DH primes as built
      into Exim, default to IKE id 23 from RFC 5114 (2048 bit).  Make
      tls_dhparam take prime identifiers.  Also unbreak combination of
      OpenSSL+DH_params+TLSSNI.

PP/39 Disable SSLv2 by default in OpenSSL support.


Exim version 4.77
-----------------

PP/01 Solaris build fix for Oracle's LDAP libraries.
      Bugzilla 1109, patch from Stephen Usher.

TF/01 HP/UX build fix: avoid arithmetic on a void pointer.

TK/01 DKIM Verification: Fix relaxed canon for empty headers w/o
      whitespace trailer

TF/02 Fix a couple more cases where we did not log the error message
      when unlink() failed. See also change 4.74-TF/03.

TF/03 Make the exiwhat support code safe for signals. Previously Exim might
      lock up or crash if it happened to be inside a call to libc when it
      got a SIGUSR1 from exiwhat.

      The SIGUSR1 handler appends the current process status to the process
      log which is later printed by exiwhat. It used to use the general
      purpose logging code to do this, but several functions it calls are
      not safe for signals.

      The new output code in the SIGUSR1 handler is specific to the process
      log, and simple enough that it's easy to inspect for signal safety.
      Removing some special cases also simplifies the general logging code.
      Removing the spurious timestamps from the process log simplifies
      exiwhat.

TF/04 Improved ratelimit ACL condition.

      The /noupdate option has been deprecated in favour of /readonly which
      has clearer semantics. The /leaky, /strict, and /readonly update modes
      are mutually exclusive. The update mode is no longer included in the
      database key; it just determines when the database is updated. (This
      means that when you upgrade Exim will forget old rate measurements.)

      Exim now checks that the per_* options are used with an update mode that
      makes sense for the current ACL. For example, when Exim is processing a
      message (e.g. acl_smtp_rcpt or acl_smtp_data, etc.) you can specify
      per_mail/leaky or per_mail/strict; otherwise (e.g. in acl_smtp_helo) you
      must specify per_mail/readonly. If you omit the update mode it defaults to
      /leaky where that makes sense (as before) or /readonly where required.

      The /noupdate option is now undocumented but still supported for
      backwards compatibility. It is equivalent to /readonly except that in
      ACLs where /readonly is required you may specify /leaky/noupdate or
      /strict/noupdate which are treated the same as /readonly.

      A useful new feature is the /count= option. This is a generalization
      of the per_byte option, so that you can measure the throughput of other
      aggregate values. For example, the per_byte option is now equivalent
      to per_mail/count=${if >{0}{$message_size} {0} {$message_size} }.

      The per_rcpt option has been generalized using the /count= mechanism
      (though it's more complicated than the per_byte equivalence). When it is
      used in acl_smtp_rcpt, the per_rcpt option adds recipients to the
      measured rate one at a time; if it is used later (e.g. in acl_smtp_data)
      or in a non-SMTP ACL it adds all the recipients in one go. (The latter
      /count=$recipients_count behaviour used to work only in non-SMTP ACLs.)
      Note that using per_rcpt with a non-readonly update mode in more than
      one ACL will cause the recipients to be double-counted. (The per_mail
      and per_byte options don't have this problem.)

      The handling of very low rates has changed slightly. If the computed rate
      is less than the event's count (usually one) then this event is the first
      after a long gap. In this case the rate is set to the same as this event's
      count, so that the first message of a spam run is counted properly.

      The major new feature is a mechanism for counting the rate of unique
      events. The new per_addr option counts the number of different
      recipients that someone has sent messages to in the last time period. It
      behaves like per_rcpt if all the recipient addresses are different, but
      duplicate recipient addresses do not increase the measured rate. Like
      the /count= option this is a general mechanism, so the per_addr option
      is equivalent to per_rcpt/unique=$local_part@$domain. You can, for
      example, measure the rate that a client uses different sender addresses
      with the options per_mail/unique=$sender_address. There are further
      details in the main documentation.

TF/05 Removed obsolete $Cambridge$ CVS revision strings.

TF/06 Removed a few PCRE remnants.

TF/07 Automatically extract Exim's version number from tags in the git
      repository when doing development or release builds.

PP/02 Raise smtp_cmd_buffer_size to 16kB.
      Bugzilla 879.  Patch from Paul Fisher.

PP/03 Implement SSL-on-connect outbound with protocol=smtps on smtp transport.
      Heavily based on revision 40f9a89a from Simon Arlott's tree.
      Bugzilla 97.

PP/04 Use .dylib instead of .so for dynamic library loading on MacOS.

PP/05 Variable $av_failed, true if the AV scanner deferred.
      Bugzilla 1078.  Patch from John Horne.

PP/06 Stop make process more reliably on build failure.
      Bugzilla 1087.  Patch from Heiko Schlittermann.

PP/07 Make maildir_use_size_file an _expandable_ boolean.
      Bugzilla 1089.  Patch from Heiko Schlittermann.

PP/08 Handle ${run} returning more data than OS pipe buffer size.
      Bugzilla 1131.  Patch from Holger Weiß.

PP/09 Handle IPv6 addresses with SPF.
      Bugzilla 860.  Patch from Wolfgang Breyha.

PP/10 GnuTLS: support TLS 1.2 & 1.1.
      Bugzilla 1156.
      Use gnutls_certificate_verify_peers2() [patch from Andreas Metzler].
      Bugzilla 1095.

PP/11 match_* no longer expand right-hand-side by default.
      New compile-time build option, EXPAND_LISTMATCH_RHS.
      New expansion conditions, "inlist", "inlisti".

PP/12 fix uninitialised greeting string from PP/03 (smtps client support).

PP/13 shell and compiler warnings fixes for RC1-RC4 changes.

PP/14 fix log_write() format string regression from TF/03.
      Bugzilla 1152.  Patch from Dmitry Isaikin.


Exim version 4.76
-----------------

PP/01 The new ldap_require_cert option would segfault if used.  Fixed.

PP/02 Harmonised TLS library version reporting; only show if debugging.
      Layout now matches that introduced for other libraries in 4.74 PP/03.

PP/03 New openssl_options items: no_sslv2 no_sslv3 no_ticket no_tlsv1

PP/04 New "dns_use_edns0" global option.

PP/05 Don't segfault on misconfiguration of ref:name exim-user as uid.
      Bugzilla 1098.

PP/06 Extra paranoia around buffer usage at the STARTTLS transition.
      nb: Exim is not vulnerable to http://www.kb.cert.org/vuls/id/555316

TK/01 Updated PolarSSL code to 0.14.2.
      Bugzilla 1097. Patch from Andreas Metzler.

PP/07 Catch divide-by-zero in ${eval:...}.
      Fixes bugzilla 1102.

PP/08 Condition negation of bool{}/bool_lax{} did not negate.  Fixed.
      Bugzilla 1104.

TK/02 Bugzilla 1106: CVE-2011-1764 - DKIM log line was subject to a
      format-string attack -- SECURITY: remote arbitrary code execution.

TK/03 SECURITY - DKIM signature header parsing was double-expanded, second
      time unintentionally subject to list matching rules, letting the header
      cause arbitrary Exim lookups (of items which can occur in lists, *not*
      arbitrary string expansion). This allowed for information disclosure.

PP/09 Fix another SIGFPE (x86) in ${eval:...} expansion, this time related to
      INT_MIN/-1 -- value coerced to INT_MAX.


Exim version 4.75
-----------------

NM/01 Workaround for PCRE version dependency in version reporting
      Bugzilla 1073

TF/01 Update valgrind.h and memcheck.h to copies from valgrind-3.6.0.
      This fixes portability to compilers other than gcc, notably
      Solaris CC and HP-UX CC. Fixes Bugzilla 1050.

TF/02 Bugzilla 139: Avoid using the += operator in the modular lookup
      makefiles for portability to HP-UX and POSIX correctness.

PP/01 Permit LOOKUP_foo enabling on the make command-line.
      Also via indented variable definition in the Makefile.
      (Debugging by Oliver Heesakkers).

PP/02 Restore caching of spamd results with expanded spamd_address.
      Patch from author of expandable spamd_address patch, Wolfgang Breyha.

PP/03 Build issue: lookups-Makefile now exports LC_ALL=C
      Improves build reliability.  Fix from: Frank Elsner

NM/02 Fix wide character breakage in the rfc2047 coding
      Fixes bug 1064. Patch from Andrey N. Oktyabrski

NM/03 Allow underscore in dnslist lookups
      Fixes bug 1026. Patch from Graeme Fowler

PP/04 Bugzilla 230: Support TLS-enabled LDAP (in addition to ldaps).
      Code patches from Adam Ciarcinski of NetBSD.

NM/04 Fixed exiqgrep to cope with mailq missing size issue
      Fixes bug 943.

PP/05 Bugzilla 1083: when lookup expansion defers, escape the output which
      is logged, to avoid truncation. Patch from John Horne.

PP/06 Bugzilla 1042: implement freeze_signal on pipe transports.
      Patch from Jakob Hirsch.

PP/07 Bugzilla 1061: restrict error messages sent over SMTP to not reveal
      SQL string expansion failure details.
      Patch from Andrey Oktyabrski.

PP/08 Bugzilla 486: implement %M datestamping in log filenames.
      Patch from Simon Arlott.

PP/09 New lookups functionality failed to compile on old gcc which rejects
      extern declarations in function scope.
      Patch from Oliver Fleischmann

PP/10 Use sig_atomic_t for flags set from signal handlers.
      Check getgroups() return and improve debugging.
      Fixed developed for diagnosis in bug 927 (which turned out to be
      a kernel bug).

PP/11 Bugzilla 1055: Update $message_linecount for maildir_tag.
      Patch from Mark Zealey.

PP/12 Bugzilla 1056: Improved spamd server selection.
      Patch from Mark Zealey.

PP/13 Bugzilla 1086: Deal with maildir quota file races.
      Based on patch from Heiko Schlittermann.

PP/14 Bugzilla 1019: DKIM multiple signature generation fix.
      Patch from Uwe Doering, sign-off by Michael Haardt.

NM/05 Fix to spam.c to accommodate older gcc versions which dislike
      variable declaration deep within a block.  Bug and patch from
      Dennis Davis.

PP/15 lookups-Makefile IRIX compatibility coercion.

PP/16 Make DISABLE_DKIM build knob functional.

NM/06 Bugzilla 968: child_open_uid: restore default SIGPIPE handler
      Patch by Simon Arlott

TF/03 Fix valgrind.h portability to C89 compilers that do not support
      variable argument macros. Our copy now differs from upstream.


Exim version 4.74
-----------------

TF/01 Failure to get a lock on a hints database can have serious
      consequences so log it to the panic log.

TF/02 Log LMTP confirmation messages in the same way as SMTP,
      controlled using the smtp_confirmation log selector.

TF/03 Include the error message when we fail to unlink a spool file.

DW/01 Bugzilla 139: Support dynamically loaded lookups as modules.
      With thanks to Steve Haslam, Johannes Berg & Serge Demonchaux
      for maintaining out-of-tree patches for some time.

PP/01 Bugzilla 139: Documentation and portability issues.
      Avoid GNU Makefile-isms, let Exim continue to build on BSD.
      Handle per-OS dynamic-module compilation flags.

PP/02 Let /dev/null have normal permissions.
      The 4.73 fixes were a little too stringent and complained about the
      permissions on /dev/null.  Exempt it from some checks.
      Reported by Andreas M. Kirchwitz.

PP/03 Report version information for many libraries, including
      Exim version information for dynamically loaded libraries.  Created
      version.h, now support a version extension string for distributors
      who patch heavily. Dynamic module ABI change.

PP/04 CVE-2011-0017 - check return value of setuid/setgid. This is a
      privilege escalation vulnerability whereby the Exim run-time user
      can cause root to append content of the attacker's choosing to
      arbitrary files.

PP/05 Bugzilla 1041: merged DCC maintainer's fixes for return code.
      (Wolfgang Breyha)

PP/06 Bugzilla 1071: fix delivery logging with untrusted macros.
      If dropping privileges for untrusted macros, we disabled normal logging
      on the basis that it would fail; for the Exim run-time user, this is not
      the case, and it resulted in successful deliveries going unlogged.
      Fixed.  Reported by Andreas Metzler.


Exim version 4.73
-----------------

PP/01 Date: & Message-Id: revert to normally being appended to a message,
      only prepend for the Resent-* case.  Fixes regression introduced in
      Exim 4.70 by NM/22 for Bugzilla 607.

PP/02 Include check_rfc2047_length in configure.default because we're seeing
      increasing numbers of administrators be bitten by this.

JJ/01 Added DISABLE_DKIM and comment to src/EDITME

PP/03 Bugzilla 994: added openssl_options main configuration option.

PP/04 Bugzilla 995: provide better SSL diagnostics on failed reads.

PP/05 Bugzilla 834: provide a permit_coredump option for pipe transports.

PP/06 Adjust NTLM authentication to handle SASL Initial Response.

PP/07 If TLS negotiated an anonymous cipher, we could end up with SSL but
      without a peer certificate, leading to a segfault because of an
      assumption that peers always have certificates.  Be a little more
      paranoid.  Problem reported by Martin Tscholak.

PP/08 Bugzilla 926: switch ClamAV to use the new zINSTREAM API for content
      filtering; old API available if built with WITH_OLD_CLAMAV_STREAM=yes
      NB: ClamAV planning to remove STREAM in "middle of 2010".
      CL also introduces -bmalware, various -d+acl logging additions and
      more caution in buffer sizes.

PP/09 Implemented reverse_ip expansion operator.

PP/10 Bugzilla 937: provide a "debug" ACL control.

PP/11 Bugzilla 922: Documentation dusting, patch provided by John Horne.

PP/12 Bugzilla 973: Implement --version.

PP/13 Bugzilla 752: Refuse to build/run if Exim user is root/0.

PP/14 Build without WITH_CONTENT_SCAN. Path from Andreas Metzler.

PP/15 Bugzilla 816: support multiple condition rules on Routers.

PP/16 Add bool_lax{} expansion operator and use that for combining multiple
      condition rules, instead of bool{}.  Make both bool{} and bool_lax{}
      ignore trailing whitespace.

JJ/02 prevent non-panic DKIM error from being sent to paniclog

JJ/03 added tcp_wrappers_daemon_name to allow host entries other than
      "exim" to be used

PP/17 Fix malware regression for cmdline scanner introduced in PP/08.
      Notification from Dr Andrew Aitchison.

PP/18 Change ClamAV response parsing to be more robust and to handle ClamAV's
      ExtendedDetectionInfo response format.
      Notification from John Horne.

PP/19 OpenSSL 1.0.0a compatibility const-ness change, should be backwards
      compatible.

PP/20 Added a CONTRIBUTING file.  Fixed the documentation build to use http:
      XSL and documented dependency on system catalogs, with examples of how
      it normally works.

DW/21 Added Valgrind hooks in store.c to help it capture out-of-bounds store
      access.

DW/22 Bugzilla 1044: CVE-2010-4345 - partial fix: restrict default behaviour
      of CONFIGURE_OWNER and CONFIGURE_GROUP options to no longer allow a
      configuration file which is writeable by the Exim user or group.

DW/23 Bugzilla 1044: CVE-2010-4345 - part two: extend checks for writeability
      of configuration files to cover files specified with the -C option if
      they are going to be used with root privileges, not just the default
      configuration file.

DW/24 Bugzilla 1044: CVE-2010-4345 - part three: remove ALT_CONFIG_ROOT_ONLY
      option (effectively making it always true).

DW/25 Add TRUSTED_CONFIG_PREFIX_FILE option to allow alternative configuration
      files to be used while preserving root privileges.

DW/26 Set FD_CLOEXEC on SMTP sockets after forking in the daemon, to ensure
      that rogue child processes cannot use them.

PP/27 Bugzilla 1047: change the default for system_filter_user to be the Exim
      run-time user, instead of root.

PP/28 Add WHITELIST_D_MACROS option to let some macros be overridden by the
      Exim run-time user without dropping privileges.

DW/29 Remove use of va_copy() which breaks pre-C99 systems. Duplicate the
      result string, instead of calling string_vformat() twice with the same
      arguments.

DW/30 Allow TRUSTED_CONFIG_PREFIX_FILE only for Exim or CONFIGURE_OWNER, not
      for other users. Others should always drop root privileges if they use
      -C on the command line, even for a whitelisted configure file.

DW/31 Turn TRUSTED_CONFIG_PREFIX_FILE into TRUSTED_CONFIG_FILE. No prefixes.

NM/01 Fixed bug #1002 - Message loss when using multiple deliveries


Exim version 4.72
-----------------

JJ/01 installed exipick 20100104.1, adding $max_received_linelength,
      $data_path, and $header_path variables; fixed documentation bugs and
      typos

JJ/02 installed exipick 20100222.0, added --input-dir and --finput to allow
      exipick to access non-standard spools, including the "frozen" queue
      (Finput)

NM/01 Bugzilla 965: Support mysql stored procedures.
      Patch from Alain Williams

NM/02 Bugzilla 961: Spacing fix (syntax error) on Makefile directives for NetBSD

NM/03 Bugzilla 955: Documentation fix for max_rcpts.
      Patch from Andreas Metzler

NM/04 Bugzilla 954: Fix for unknown responses from Dovecot authenticator.
      Patch from Kirill Miazine

NM/05 Bugzilla 671: Added umask to procmail example.

JJ/03 installed exipick 20100323.0, fixing doc bug

NM/06 Bugzilla 988: CVE-2010-2023 - prevent hardlink attack on sticky mail
      directory.  Notification and patch from Dan Rosenberg.

TK/01 PDKIM: Upgrade PolarSSL files to upstream version 0.12.1.

TK/02 Improve log output when DKIM signing operation fails.

MH/01 Treat the transport option dkim_domain as a colon separated
      list, not as a single string, and sign the message with each element,
      omitting multiple occurences of the same signer.

NM/07 Null terminate DKIM strings, Null initialise DKIM variable
      Bugzilla 985, 986.  Patch by Simon Arlott

NM/08 Bugzilla 967. dnsdb DNS TXT record bug fix (DKIM-related)
      Patch by Simon Arlott

PP/01 Bugzilla 989: CVE-2010-2024 - work round race condition on
      MBX locking.  Notification from Dan Rosenberg.


Exim version 4.71
-----------------

TK/01 Bugzilla 912: Fix DKIM segfault on empty headers/body.

NM/01 Bugzilla 913: Documentation fix for gnutls_* options.

NM/02 Bugzilla 722: Documentation for randint.  Better randomness defaults.

NM/03 Bugzilla 847: Enable DNSDB lookup by default.

NM/04 Bugzilla 915: Flag broken perl installation during build.


Exim version 4.70
-----------------

TK/01 Added patch by Johannes Berg that expands the main option
      "spamd_address" if it starts with a dollar sign.

TK/02 Write list of recipients to X-Envelope-Sender header when building
      the mbox-format spool file for content scanning (suggested by Jakob
      Hirsch).

TK/03 Added patch by Wolfgang Breyha that adds experimental DCC
      (http://www.dcc-servers.net/) support via dccifd. Activated by
      setting EXPERIMENTAL_DCC=yes in Local/Makefile.

TK/04 Bugzilla 673: Add f-protd malware scanner support. Patch submitted
      by Mark Daniel Reidel <mr@df.eu>.

NM/01 Bugzilla 657: Embedded PCRE removed from the exim source tree.
      When building exim an external PCRE library is now needed -
      PCRE is a system library on the majority of modern systems.
      See entry on PCRE_LIBS in EDITME file.

NM/02 Bugzilla 646: Removed unwanted C/R in Dovecot authenticator
      conversation.  Added nologin parameter to request.
      Patch contributed by Kirill Miazine.

TF/01 Do not log submission mode rewrites if they do not change the address.

TF/02 Bugzilla 662: Fix stack corruption before exec() in daemon.c.

NM/03 Bugzilla 602: exicyclog now handles panic log, and creates empty
      log files in place.  Contributed by Roberto Lima.

NM/04 Bugzilla 667: Close socket used by dovecot authenticator.

TF/03 Bugzilla 615: When checking the local_parts router precondition
      after a local_part_suffix or local_part_prefix option, Exim now
      does not use the address's named list lookup cache, since this
      contains cached lookups for the whole local part.

NM/05 Bugzilla 521: Integrated SPF Best Guess support contributed by
      Robert Millan.  Documentation is in experimental-spec.txt.

TF/04 Bugzilla 668: Fix parallel build (make -j).

NM/05.2 Bugzilla 437: Prevent Maildir aux files being created with mode 000.

NM/05.3 Bugzilla 598: Improvement to Dovecot authenticator handling.
      Patch provided by Jan Srzednicki.

TF/05 Leading white space used to be stripped from $spam_report which
      wrecked the formatting. Now it is preserved.

TF/06 Save $spam_score, $spam_bar, and $spam_report in spool files, so
      that they are available at delivery time.

TF/07 Fix the way ${extract is skipped in the untaken branch of a conditional.

TF/08 TLS error reporting now respects the incoming_interface and
      incoming_port log selectors.

TF/09 Produce a more useful error message if an SMTP transport's hosts
      setting expands to an empty string.

NM/06 Bugzilla 744: EXPN did not work under TLS.
      Patch provided by Phil Pennock.

NM/07 Bugzilla 769: Extraneous comma in usage fprintf
      Patch provided by Richard Godbee.

NM/08 Fixed erroneous documentation references to smtp_notquit_acl to be
      acl_smtp_notquit, added index entry.

NM/09 Bugzilla 787: Potential buffer overflow in string_format.
      Patch provided by Eugene Bujak.

NM/10 Bugzilla 770: Problem on some platforms modifying the len parameter to
      accept(). Patch provided by Maxim Dounin.

NM/11 Bugzilla 749: Preserve old behaviour of blanks comparing equal to zero.
      Patch provided by Phil Pennock.

NM/12 Bugzilla 497: Correct behaviour of exiwhat when no config exists.

NM/13 Bugzilla 590: Correct handling of Resent-Date headers.
      Patch provided by Brad "anomie" Jorsch.

NM/14 Bugzilla 622: Added timeout setting to transport filter.
      Patch provided by Dean Brooks.

TK/05 Add native DKIM support (does not depend on external libraries).

NM/15 Bugzilla 854: Removed code that symlinks to pcre as its no longer useful.
      Patch provided by Graeme Fowler.

NM/16 Bugzilla 851: Documentation example syntax fix.

NM/17 Changed NOTICE file to remove references to embedded PCRE.

NM/18 Bugzilla 894: Fix issue with very long lines including comments in
      lsearch.

NM/19 Bugzilla 745: TLS version reporting.
      Patch provided by Phil Pennock.

NM/20 Bugzilla 167: bool: condition support.
      Patch provided by Phil Pennock.

NM/21 Bugzilla 665: gnutls_compat_mode to allow compatibility with broken
      clients. Patch provided by Phil Pennock.

NM/22 Bugzilla 607: prepend (not append) Resent-Message-ID and Resent-Date.
      Patch provided by Brad "anomie" Jorsch.

NM/23 Bugzilla 687: Fix misparses in eximstats.
      Patch provided by Heiko Schlittermann.

NM/24 Bugzilla 688: Fix exiwhat to handle log_selector = +pid.
      Patch provided by Heiko Schlittermann.

NM/25 Bugzilla 727: Use transport mode as default mode for maildirsize file.
      plus update to original patch.

NM/26 Bugzilla 799: Documentation correction for ratelimit.

NM/27 Bugzilla 802: Improvements to local interface IP addr detection.
      Patch provided by David Brownlee.

NM/28 Bugzilla 807: Improvements to LMTP delivery logging.

NM/29 Bugzilla 862, 866, 875: Documentation bugfixes.

NM/30 Bugzilla 888: TLS documentation bugfixes.

NM/31 Bugzilla 896: Dovecot buffer overrun fix.

NM/32 Bugzilla 889: Change all instances of "expr" in shell scripts to "expr --"
      Unlike the original bugzilla I have changed all shell scripts in src tree.

NM/33 Bugzilla 898: Transport filter timeout fix.
      Patch by Todd Rinaldo.

NM/34 Bugzilla 901: Fix sign/unsigned and UTF mismatches.
      Patch by Serge Demonchaux.

NM/35 Bugzilla 39: Base64 decode bug fixes.
      Patch by Jakob Hirsch.

NM/36 Bugzilla 909: Correct connect() call in dcc code.

NM/37 Bugzilla 910: Correct issue with relaxed/simple handling.

NM/38 Bugzilla 908: Removed NetBSD3 support as no longer needed.

NM/39 Bugzilla 911: Fixed MakeLinks build script.


Exim version 4.69
-----------------

TK/01 Add preliminary DKIM support. Currently requires a forked version of
      ALT-N's libdkim that I have put here:
      http://duncanthrax.net/exim-experimental/

      Note to Michael Haardt: I had to rename some vars in sieve.c. They
      were called 'true' and it seems that C99 defines that as a reserved
      keyword to be used with 'bool' variable types. That means you could
      not include C99-style headers which use bools without triggering
      build errors in sieve.c.

NM/01 Bugzilla 592: --help option is handled incorrectly if exim is invoked
      as mailq or other aliases.  Changed the --help handling significantly
      to do whats expected.  exim_usage() emits usage/help information.

SC/01 Added the -bylocaldomain option to eximstats.

NM/02 Bugzilla 619: Defended against bad data coming back from gethostbyaddr.

NM/03 Bugzilla 613: Documentation fix for acl_not_smtp.

NM/04 Bugzilla 628: PCRE update to 7.4 (work done by John Hall).


Exim version 4.68
-----------------

PH/01 Another patch from the Sieve maintainer.

PH/02 When an IPv6 address is converted to a string for single-key lookup
      in an address list (e.g. for an item such as "net24-dbm;/net/works"),
      dots are used instead of colons so that keys in lsearch files need not
      contain colons. This was done some time before quoting was made available
      in lsearch files. However, iplsearch files do require colons in IPv6 keys
      (notated using the quote facility) so as to distinguish them from IPv4
      keys. This meant that lookups for IP addresses in host lists did not work
      for iplsearch lookups.

      This has been fixed by arranging for IPv6 addresses to be expressed with
      colons if the lookup type is iplsearch. This is not incompatible, because
      previously such lookups could never work.

      The situation is now rather anomalous, since one *can* have colons in
      ordinary lsearch keys. However, making the change in all cases is
      incompatible and would probably break a number of configurations.

TK/01 Change PRVS address formatting scheme to reflect latests BATV draft
      version.

MH/01 The "spam" ACL condition code contained a sscanf() call with a %s
      conversion specification without a maximum field width, thereby enabling
      a rogue spamd server to cause a buffer overflow. While nobody in their
      right mind would setup Exim to query an untrusted spamd server, an
      attacker that gains access to a server running spamd could potentially
      exploit this vulnerability to run arbitrary code as the Exim user.

TK/02 Bugzilla 502: Apply patch to make the SPF-Received: header use
      $primary_hostname instead of what libspf2 thinks the hosts name is.

MH/02 The dsearch lookup now uses lstat(2) instead of stat(2) to look for
      a directory entry by the name of the lookup key. Previously, if a
      symlink pointed to a non-existing file or a file in a directory that
      Exim lacked permissions to read, a lookup for a key matching that
      symlink would fail. Now it is enough that a matching directory entry
      exists, symlink or not. (Bugzilla 503.)

PH/03 The body_linecount and body_zerocount variables are now exported in the
      local_scan API.

PH/04 Added the $dnslist_matched variable.

PH/05 Unset $tls_cipher and $tls_peerdn before making a connection as a client.
      This means they are set thereafter only if the connection becomes
      encrypted.

PH/06 Added the client_condition to authenticators so that some can be skipped
      by clients under certain conditions.

PH/07 The error message for a badly-placed control=no_multiline_responses left
      "_responses" off the end of the name.

PH/08 Added -Mvc to output a copy of a message in RFC 2822 format.

PH/09 Tidied the code for creating ratelimiting keys, creating them explicitly
      (without spaces) instead of just copying the configuration text.

PH/10 Added the /noupdate option to the ratelimit ACL condition.

PH/11 Added $max_received_linelength.

PH/12 Added +ignore_defer and +include_defer to host lists.

PH/13 Installed PCRE version 7.2. This needed some changes because of the new
      way in which PCRE > 7.0 is built.

PH/14 Implemented queue_only_load_latch.

PH/15 Removed an incorrect (int) cast when reading the value of SIZE in a
      MAIL command. The effect was to mangle the value on 64-bit systems.

PH/16 Another patch from the Sieve maintainer.

PH/17 Added the NOTQUIT ACL, based on a patch from Ted Cooper.

PH/18 If a system quota error occurred while trying to create the file for
      a maildir delivery, the message "Mailbox is full" was not appended to the
      bounce if the delivery eventually timed out. Change 4.67/27 below applied
      only to a quota excession during the actual writing of the file.

PH/19 It seems that peer DN values may contain newlines (and other non-printing
      characters?) which causes problems in log lines. The DN values are now
      passed through string_printing() before being added to log lines.

PH/20 Added the "servers=" facility to MySQL and PostgreSQL lookups. (Oracle
      and InterBase are left for another time.)

PH/21 Added message_body_newlines option.

PH/22 Guard against possible overflow in moan_check_errorcopy().

PH/23 POSIX allows open() to be a macro; guard against that.

PH/24 If the recipient of an error message contained an @ in the local part
      (suitably quoted, of course), incorrect values were put in $domain and
      $local_part during the evaluation of errors_copy.


Exim version 4.67
-----------------

MH/01 Fix for bug #448, segfault in Dovecot authenticator when interface_address
      is unset (happens when testing with -bh and -oMi isn't used). Thanks to
      Jan Srzednicki.

PH/01 Added a new log selector smtp_no_mail, to log SMTP sessions that do not
      issue a MAIL command.

PH/02 In an ACL statement such as

        deny dnslists = X!=127.0.0.2 : X=127.0.0.2

      if a client was not listed at all, or was listed with a value other than
      127.0.0.2, in the X list, but was listed with 127.0.0.2 in the Y list,
      the condition was not true (as it should be), so access was not denied.
      The bug was that the ! inversion was incorrectly passed on to the second
      item. This has been fixed.

PH/03 Added additional dnslists conditions == and =& which are different from
      = and & when the dns lookup returns more than one IP address.

PH/04 Added gnutls_require_{kx,mac,protocols} to give more control over the
      cipher suites used by GnuTLS. These options are ignored by OpenSSL.

PH/05 After discussion on the list, added a compile time option ENABLE_DISABLE_
      FSYNC, which compiles an option called disable_fsync that allows for
      bypassing fsync(). The documentation is heavily laced with warnings.

SC/01 Updated eximstats to collate all SpamAssassin rejects into one bucket.

PH/06 Some tidies to the infrastructure of the Test Suite that is concerned
      with the auxiliary C programs that it uses: (1) Arrange for BIND_8_COMPAT
      to be defined when compiling on OSX (Darwin); (2) Tidies to the Makefile,
      including adding "make clean"; (3) Added -fPIC when compiling the test
      dynamically loaded module, to get rid of a warning.

MH/02 Fix for bug #451, causing paniclog entries to be written if a bounce
      message fails, move_frozen_messages = true and ignore_bounce_errors_after
      = 0s. The bug is otherwise harmless.

PH/07 There was a bug in the dovecot authenticator such that the value of
      $auth1 could be overwritten, and so not correctly preserved, after a
      successful authentication. This usually meant that the value preserved by
      the server_setid option was incorrect.

PH/08 Added $smtp_count_at_connection_start, deliberately with a long name.

PH/09 Installed PCRE release 7.0.

PH/10 The acl_not_smtp_start ACL was, contrary to the documentation, not being
      run for batched SMTP input. It is now run at the start of every message
      in the batch. While fixing this I discovered that the process information
      (output by running exiwhat) was not always getting set for -bs and -bS
      input. This is fixed, and it now also says "batched" for BSMTP.

PH/11 Added control=no_pipelining.

PH/12 Added $sending_ip_address and $sending_port (mostly Magnus Holmgren's
      patch, slightly modified), and move the expansion of helo_data till after
      the connection is made in the smtp transport (so it can use these
      values).

PH/13 Added ${rfc2047d: to decoded RFC 2047 strings.

PH/14 Added log_selector = +pid.

PH/15 Flush SMTP output before delaying, unless control=no_delay_flush is set.

PH/16 Add ${if forany and ${if forall.

PH/17 Added dsn_from option to vary the From: line in DSNs.

PH/18 Flush SMTP output before performing a callout, unless control =
      no_callout_flush is set.

PH/19 Change 4.64/PH/36 introduced a bug: when address_retry_include_sender
      was true (the default) a successful delivery failed to delete the retry
      item, thus causing premature timeout of the address. The bug is now
      fixed.

PH/20 Added hosts_avoid_pipelining to the smtp transport.

PH/21 Long custom messages for fakedefer and fakereject are now split up
      into multiline responses in the same way that messages for "deny" and
      other ACL rejections are.

PH/22 Applied Jori Hamalainen's speed-up changes and typo fixes to exigrep,
      with slight modification.

PH/23 Applied sieve patches from the maintainer "tracking the latest notify
      draft, changing the syntax and factoring some duplicate code".

PH/24 When the log selector "outgoing_port" was set, the port was shown as -1
      for deliveries of the second and subsequent messages over the same SMTP
      connection.

PH/25 Applied Magnus Holmgren's patch for ${addresses, ${map, ${filter, and
      ${reduce, with only minor "tidies".

SC/02 Applied Daniel Tiefnig's patch to improve the '($parent) =' pattern match.

PH/26 Added a "continue" ACL modifier that does nothing, for the benefit of its
      expansion side effects.

PH/27 When a message times out after an over-quota error from an Exim-imposed
      quota, the bounce message says "mailbox is full". This message was not
      being given when it was a system quota that was exceeded. It now should
      be the same.

MH/03 Made $recipients available in local_scan(). local_scan() already has
      better access to the recipient list through recipients_list[], but
      $recipients can be useful in postmaster-provided expansion strings.

PH/28 The $smtp_command and $smtp_command_argument variables were not correct
      in the case of a MAIL command with additional options following the
      address, for example: MAIL FROM:<foo@bar> SIZE=1234. The option settings
      were accidentally chopped off.

PH/29 SMTP synchronization checks are implemented when a command is read -
      there is a check that no more input is waiting when there shouldn't be
      any. However, for some commands, a delay in an ACL can mean that it is
      some time before the response is written. In this time, more input might
      arrive, invalidly. So now there are extra checks after an ACL has run for
      HELO/EHLO and after the predata ACL, and likewise for MAIL and RCPT when
      pipelining has not been advertised.

PH/30 MH's patch to allow iscntrl() characters to be list separators.

PH/31 Unlike :fail:, a custom message specified with :defer: was not being
      returned in the SMTP response when smtp_return_error_details was false.
      This has been fixed.

PH/32 Change the Dovecot authenticator to use read() and write() on the socket
      instead of the C I/O that was originally supplied, because problems were
      reported on Solaris.

PH/33 Compile failed with OpenSSL 0.9.8e. This was due to a coding error in
      Exim which did not show up earlier: it was assuming that a call to
      SSL_CTX_set_info_callback() might give an error value. In fact, there is
      no error. In previous releases of OpenSSL, SSL_CTX_set_info_callback()
      was a macro that became an assignment, so it seemed to work. This has
      changed to a proper function call with a void return, hence the compile
      error. Exim's code has been fixed.

PH/34 Change HDA_SIZE in oracle.c from 256 to 512. This is needed for 64-bit
      cpus.

PH/35 Applied a patch from the Sieve maintainer which fixes a bug in "notify".

PH/36 Applied John Jetmore's patch to add -v functionality to exigrep.

PH/37 If a message is not accepted after it has had an id assigned (e.g.
      because it turns out to be too big or there is a timeout) there is no
      "Completed" line in the log. When some messages of this type were
      selected by exigrep, they were listed as "not completed". Others were
      picked up by some special patterns. I have improved the selection
      criteria to be more general.

PH/38 The host_find_failed option in the manualroute router can now be set
      to "ignore", to completely ignore a host whose IP address cannot be
      found. If all hosts are ignored, the behaviour is controlled by the new
      host_all_ignored option.

PH/39 In a list of hosts for manualroute, if one item (either because of multi-
      homing or because of multiple MX records with /mx) generated more than
      one IP address, and the following item turned out to be the local host,
      all the secondary addresses of the first item were incorrectly removed
      from the list, along with the local host and any following hosts (which
      is what is supposed to happen).

PH/40 When Exim receives a message, it writes the login name, uid, and gid of
      whoever called Exim into the -H file. In the case of the daemon it was
      behaving confusingly. When first started, it used values for whoever
      started the daemon, but after a SIGHUP it used the Exim user (because it
      calls itself on a restart). I have changed the code so that it now always
      uses the Exim user.

PH/41 (Following a suggestion from Tony Finch) If all the RCPT commands in a
      message are rejected with the same error (e.g. no authentication or bad
      sender address), and a DATA command is nevertheless sent (as can happen
      with PIPELINING or a stupid MUA), the error message that was given to the
      RCPT commands is included in the rejection of the DATA command. This is
      intended to be helpful for MUAs that show only the final error to their
      users.

PH/42 Another patch from the Sieve maintainer.

SC/02 Eximstats - Differentiate between permanent and temporary rejects.
      Eximstats - Fixed some broken HTML links and added missing column headers
                  (Jez Hancock).
      Eximstats - Fixed Grand Total Summary Domains, Edomains, and Email
                  columns for Rejects, Temp Rejects, Ham, and Spam rows.

SC/03 Eximstats - V1.58 Fix to get <> and blackhole to show in edomain tables.

PH/43 Yet another patch from the Sieve maintainer.

PH/44 I found a way to check for a TCP/IP connection going away before sending
      the response to the final '.' that terminates a message, but only in the
      case where the client has not sent further data following the '.'
      (unfortunately, this is allowed). However, in many cases there won't be
      any further data because there won't be any more messages to send. A call
      to select() can be used: if it shows that the input is "ready", there is
      either input waiting, or the socket has been closed. An attempt to read
      the next input character can distinguish the two cases. Previously, Exim
      would have sent an OK response which the client would never have see.
      This could lead to message repetition. This fix should cure that, at
      least in a lot of common cases.

PH/45 Do not advertise STARTTLS in response to HELP unless it would be
      advertised in response to EHLO.


Exim version 4.66
-----------------

PH/01 Two more bugs that were introduced by 4.64/PH/07, in addition to the one
      fixed by 4.65/MH/01 (is this a record?) are fixed:

      (i)  An empty string was always treated as zero by the numeric comparison
           operators. This behaviour has been restored.

      (ii) It is documented that the numeric comparison operators always treat
           their arguments as decimal numbers. This was broken in that numbers
           starting with 0 were being interpreted as octal.

      While fixing these problems I realized that there was another issue that
      hadn't been noticed. Values of message_size_limit (both the global option
      and the transport option) were treated as octal if they started with 0.
      The documentation was vague. These values are now always treated as
      decimal, and I will make that clear in the documentation.


Exim version 4.65
-----------------

TK/01 Disable default definition of HAVE_LINUX_SENDFILE. Clashes with
      Linux large file support (_FILE_OFFSET_BITS=64) on older glibc
      versions. (#438)

MH/01 Don't check that the operands of numeric comparison operators are
      integers when their expansion is in "skipping" mode (fixes bug
      introduced by 4.64-PH/07).

PH/01 If a system filter or a router generates more than SHRT_MAX (32767)
      child addresses, Exim now panics and dies. Previously, because the count
      is held in a short int, deliveries were likely to be lost. As such a
      large number of recipients for a single message is ridiculous
      (performance will be very, very poor), I have chosen to impose a limit
      rather than extend the field.


Exim version 4.64
-----------------

TK/01 Bugzilla #401. Fix DK spooling code so that it can overwrite a
      leftover -K file (the existence of which was triggered by #402).
      While we were at it, introduced process PID as part of the -K
      filename. This should rule out race conditions when creating
      these files.

TK/02 Bugzilla #402. Apply patch from Simon Arlott, speeding up DK signing
      processing considerably. Previous code took too long for large mails,
      triggering a timeout which in turn triggers #401.

TK/03 Introduced HAVE_LINUX_SENDFILE to os.h-Linux. Currently only used
      in the DK code in transports.c. sendfile() is not really portable,
      hence the _LINUX specificness.

TF/01 In the add_headers option to the mail command in an Exim filter,
      there was a bug that Exim would claim a syntax error in any
      header after the first one which had an odd number of characters
      in the field name.

PH/01 If a server that rejects MAIL FROM:<> was the target of a sender
      callout verification, Exim cached a "reject" for the entire domain. This
      is correct for most verifications, but it is not correct for a recipient
      verification with use_sender or use_postmaster set, because in that case
      the callout does not use MAIL FROM:<>. Exim now distinguishes the special
      case of MAIL FROM:<> rejection from other early rejections (e.g.
      rejection of HELO). When verifying a recipient using a non-null MAIL
      address, the cache is ignored if it shows MAIL FROM:<> rejection.
      Whatever the result of the callout, the value of the domain cache is
      left unchanged (for any other kind of callout, getting as far as trying
      RCPT means that the domain itself is ok).

PH/02 Tidied a number of unused variable and signed/unsigned warnings that
      gcc 4.1.1 threw up.

PH/03 On Solaris, an unexpectedly close socket (dropped connection) can
      manifest itself as EPIPE rather than ECONNECT. When tidying away a
      session, the daemon ignores ECONNECT errors and logs others; it now
      ignores EPIPE as well.

PH/04 Applied Nico Erfurth's refactoring patch to tidy up mime.c
      (quoted-printable decoding).

PH/05 Applied Nico Erfurth's refactoring patch to tidy up spool_mbox.c, and
      later the small subsequent patch to fix an introduced bug.

PH/06 Installed the latest Cygwin Makefile from the Cygwin maintainer.

PH/07 There was no check for overflow in expansions such as ${if >{1}{4096M}}.

PH/08 An error is now given if message_size_limit is specified negative.

PH/09 Applied and tidied up Jakob Hirsch's patch for allowing ACL variables
      to be given (somewhat) arbitrary names.

JJ/01 exipick 20060919.0, allow for arbitrary acl_ variables introduced
      in 4.64-PH/09.

JJ/02 exipick 20060919.0, --show-vars args can now be regular expressions,
      miscellaneous code fixes

PH/10 Added the log_reject_target ACL modifier to specify where to log
      rejections.

PH/11 Callouts were setting the name used for EHLO/HELO from $smtp_active_
      hostname. This is wrong, because it relates to the incoming message (and
      probably the interface on which it is arriving) and not to the outgoing
      callout (which could be using a different interface). This has been
      changed to use the value of the helo_data option from the smtp transport
      instead - this is what is used when a message is actually being sent. If
      there is no remote transport (possible with a router that sets up host
      addresses), $smtp_active_hostname is used.

PH/12 Installed Andrey Panin's patch to add a dovecot authenticator. Various
      tweaks were necessary in order to get it to work (see also 21 below):
      (a) The code assumed that strncpy() returns a negative number on buffer
          overflow, which isn't the case. Replaced with Exim's string_format()
          function.
      (b) There were several signed/unsigned issues. I just did the minimum
          hacking in of casts. There is scope for a larger refactoring.
      (c) The code used strcasecmp() which is not a standard C function.
          Replaced with Exim's strcmpic() function.
      (d) The code set only $1; it now sets $auth1 as well.
      (e) A simple test gave the error "authentication client didn't specify
          service in request". It would seem that Dovecot has changed its
          interface. Fortunately there's a specification; I followed it and
          changed what the client sends and it appears to be working now.

PH/13 Added $message_headers_raw to provide the headers without RFC 2047
      decoding.

PH/14 Corrected misleading output from -bv when -v was also used. Suppose the
      address A is aliased to B and C, where B exists and C does not. Without
      -v the output is "A verified" because verification stops after a
      successful redirection if more than one address is generated. However,
      with -v the child addresses are also verified. Exim was outputting "A
      failed to verify" and then showing the successful verification for C,
      with its parentage. It now outputs "B failed to verify", showing B's
      parentage before showing the successful verification of C.

PH/15 Applied Michael Deutschmann's patch to allow DNS black list processing to
      look up a TXT record in a specific list after matching in a combined
      list.

PH/16 It seems that the options setting for the resolver (RES_DEFNAMES and
      RES_DNSRCH) can affect the behaviour of gethostbyname() and friends when
      they consult the DNS. I had assumed they would set it the way they
      wanted; and indeed my experiments on Linux seem to show that in some
      cases they do (I could influence IPv6 lookups but not IPv4 lookups).
      To be on the safe side, however, I have now made the interface to
      host_find_byname() similar to host_find_bydns(), with an argument
      containing the DNS resolver options. The host_find_byname() function now
      sets these options at its start, just as host_find_bydns() does. The smtp
      transport options dns_qualify_single and dns_search_parents are passed to
      host_find_byname() when gethostbyname=TRUE in this transport. Other uses
      of host_find_byname() use the default settings of RES_DEFNAMES
      (qualify_single) but not RES_DNSRCH (search_parents).

PH/17 Applied (a modified version of) Nico Erfurth's patch to make
      spool_read_header() do less string testing, by means of a preliminary
      switch on the second character of optional "-foo" lines. (This is
      overdue, caused by the large number of possibilities that now exist.
      Originally there were few.) While I was there, I also converted the
      str(n)cmp tests so they don't re-test the leading "-" and the first
      character, in the hope this might squeeze out yet more improvement.

PH/18 Two problems with "group" syntax in header lines when verifying: (1) The
      flag allowing group syntax was set by the header_syntax check but not
      turned off, possible causing trouble later; (2) The flag was not being
      set at all for the header_verify test, causing "group"-style headers to
      be rejected. I have now set it in this case, and also caused header_
      verify to ignore an empty address taken from a group. While doing this, I
      came across some other cases where the code for allowing group syntax
      while scanning a header line wasn't quite right (mostly, not resetting
      the flag correctly in the right place). These bugs could have caused
      trouble for malformed header lines. I hope it is now all correct.

PH/19 The functions {pwcheck,saslauthd}_verify_password() are always called
      with the "reply" argument non-NULL. The code, however (which originally
      came from elsewhere) had *some* tests for NULL when it wrote to *reply,
      but it didn't always do it. This confused somebody who was copying the
      code for some other use. I have removed all the tests.

PH/20 It was discovered that the GnuTLS code had support for RSA_EXPORT, a
      feature that was used to support insecure browsers during the U.S. crypto
      embargo. It requires special client support, and Exim is probably the
      only MTA that supported it -- and would never use it because real RSA is
      always available. This code has been removed, because it had the bad
      effect of slowing Exim down by computing (never used) parameters for the
      RSA_EXPORT functionality.

PH/21 On the advice of Timo Sirainen, added a check to the dovecot
      authenticator to fail if there's a tab character in the incoming data
      (there should never be unless someone is messing about, as it's supposed
      to be base64-encoded). Also added, on Timo's advice, the "secured" option
      if the connection is using TLS or if the remote IP is the same as the
      local IP, and the "valid-client-cert option" if a client certificate has
      been verified.

PH/22 As suggested by Dennis Davis, added a server_condition option to *all*
      authenticators. This can be used for authorization after authentication
      succeeds. (In the case of plaintext, it servers for both authentication
      and authorization.)

PH/23 Testing for tls_required and lost_connection in a retry rule didn't work
      if any retry times were supplied.

PH/24 Exim crashed if verify=helo was activated during an incoming -bs
      connection, where there is no client IP address to check. In this
      situation, the verify now always succeeds.

PH/25 Applied John Jetmore's -Mset patch.

PH/26 Added -bem to be like -Mset, but loading a message from a file.

PH/27 In a string expansion for a processed (not raw) header when multiple
      headers of the same name were present, leading whitespace was being
      removed from all of them, but trailing whitespace was being removed only
      from the last one. Now trailing whitespace is removed from each header
      before concatenation. Completely empty headers in a concatenation (as
      before) are ignored.

PH/28 Fixed bug in backwards-compatibility feature of PH/09 (thanks to John
      Jetmore). It would have mis-read ACL variables from pre-4.61 spool files.

PH/29 [Removed. This was a change that I later backed out, and forgot to
      correct the ChangeLog entry (that I had efficiently created) before
      committing the later change.]

PH/30 Exim was sometimes attempting to deliver messages that had suffered
      address errors (4xx response to RCPT) over the same connection as other
      messages routed to the same hosts. Such deliveries are always "forced",
      so retry times are not inspected. This resulted in far too many retries
      for the affected addresses. The effect occurred only when there were more
      hosts than the hosts_max_try setting in the smtp transport when it had
      the 4xx errors. Those hosts that it had tried were not added to the list
      of hosts for which the message was waiting, so if all were tried, there
      was no problem. Two fixes have been applied:

      (i)  If there are any address or message errors in an SMTP delivery, none
           of the hosts (tried or untried) are now added to the list of hosts
           for which the message is waiting, so the message should not be a
           candidate for sending over the same connection that was used for a
           successful delivery of some other message. This seems entirely
           reasonable: after all the message is NOT "waiting for some host".
           This is so "obvious" that I'm not sure why it wasn't done
           previously. Hope I haven't missed anything, but it can't do any
           harm, as the worst effect is to miss an optimization.

      (ii) If, despite (i), such a delivery is accidentally attempted, the
           routing retry time is respected, so at least it doesn't keep
           hammering the server.

PH/31 Installed Andrew Findlay's patch to close the writing end of the socket
      in ${readsocket because some servers need this prod.

PH/32 Added some extra debug output when updating a wait-xxx database.

PH/33 The hint "could be header name not terminated by colon", which has been
      given for certain expansion errors for a long time, was not being given
      for the ${if def:h_colon_omitted{...  case.

PH/34 The spec says: "With one important exception, whenever a domain list is
      being scanned, $domain contains the subject domain." There was at least
      one case where this was not true.

PH/35 The error "getsockname() failed: connection reset by peer" was being
      written to the panic log as well as the main log, but it isn't really
      panic-worthy as it just means the connection died rather early on. I have
      removed the panic log writing for the ECONNRESET error when getsockname()
      fails.

PH/36 After a 4xx response to a RCPT error, that address was delayed (in queue
      runs only) independently of the message's sender address. This meant
      that, if the 4xx error was in fact related to the sender, a different
      message to the same recipient with a different sender could confuse
      things. In particular, this can happen when sending to a greylisting
      server, but other circumstances could also provoke similar problems.
      I have changed the default so that the retry time for these errors is now
      based a combination of the sender and recipient addresses. This change
      can be overridden by setting address_retry_include_sender=false in the
      smtp transport.

PH/37 For LMTP over TCP/IP (the smtp transport), error responses from the
      remote server are returned as part of bounce messages. This was not
      happening for LMTP over a pipe (the lmtp transport), but now it is the
      same for both kinds of LMTP.

PH/38 Despite being documented as not happening, Exim was rewriting addresses
      in header lines that were in fact CNAMEs. This is no longer the case.

PH/39 If -R or -S was given with -q<time>, the effect of -R or -S was ignored,
      and queue runs started by the daemon processed all messages. This has
      been fixed so that -R and -S can now usefully be given with -q<time>.

PH/40 Import PCRE release 6.7 (fixes some bugs).

PH/41 Add bitwise logical operations to eval (courtesy Brad Jorsch).

PH/42 Give an error if -q is specified more than once.

PH/43 Renamed the variables $interface_address and $interface_port as
      $received_ip_address and $received_port, to make it clear that these
      values apply to message reception, and not to the outgoing interface when
      a message is delivered. (The old names remain recognized, of course.)

PH/44 There was no timeout on the connect() call when using a Unix domain
      socket in the ${readsocket expansion. There now is.

PH/45 Applied a modified version of Brad Jorsch's patch to allow "message" to
      be meaningful with "accept".

SC/01 Eximstats V1.43
     Bug fix for V1.42 with -h0 specified. Spotted by Chris Lear.

SC/02 Eximstats V1.44
      Use a glob alias rather than an array ref in the generated
      parser. This improves both readability and performance.

SC/03 Eximstats V1.45 (Marco Gaiarin / Steve Campbell)
      Collect SpamAssassin and rejection statistics.
      Don't display local sender or destination tables unless
      there is data to show.
      Added average volumes into the top table text output.

SC/04 Eximstats V1.46
      Collect data on the number of addresses (recipients)
      as well as the number of messages.

SC/05 Eximstats V1.47
      Added 'Message too big' to the list of mail rejection
      reasons (thanks to Marco Gaiarin).

SC/06 Eximstats V1.48
      Mainlog lines which have GMT offsets and are too short to
      have a flag are now skipped.

SC/07 Eximstats V1.49 (Alain Williams)
      Added the -emptyok flag.

SC/08 Eximstats V1.50
      Fixes for obtaining the IP address from reject messages.

JJ/03 exipick.20061117.2, made header handling as similar to exim as possible
      (added [br]h_ prefixes, implemented RFC2047 decoding.  Fixed
      whitespace changes from 4.64-PH/27

JJ/04 exipick.20061117.2, fixed format and added $message_headers_raw to
      match 4.64-PH/13

JJ/05 exipick.20061117.2, bug fixes (error out sooner when invalid criteria
      are found, allow negative numbers in numeric criteria)

JJ/06 exipick.20061117.2, added new $message_body_missing variable

JJ/07 exipick.20061117.2, added $received_ip_address and $received_port
      to match changes made in 4.64-PH/43

PH/46 Applied Jori Hamalainen's patch to add features to exiqsumm.

PH/47 Put in an explicit test for a DNS lookup of an address record where the
      "domain" is actually an IP address, and force a failure. This locks out
      those revolvers/nameservers that support "A-for-A" lookups, in
      contravention of the specifications.

PH/48 When a host name was looked up from an IP address, and the subsequent
      forward lookup of the name timed out, the host name was left in
      $sender_host_name, contrary to the specification.

PH/49 Although default lookup types such as lsearch* or cdb*@ have always been
      restricted to single-key lookups, Exim was not diagnosing an error if
      * or *@ was used with a query-style lookup.

PH/50 Increased the value of DH_BITS in tls-gnu.c from 768 to 1024.

MH/01 local_scan ABI version incremented to 1.1. It should have been updated
      long ago, but noone interested enough thought of it. Let's just say that
      the "1.1" means that there are some new functions that weren't there at
      some point in the past.

PH/51 Error processing for expansion failure of helo_data from an smtp
      transport during callout processing was broken.

PH/52 Applied John Jetmore's patch to allow tls-on-connect and STARTTLS to be
      tested/used via the -bh/-bhc/-bs options.

PH/53 Added missing "#include <time.h>" to pcre/pcretest.c (this was a PCRE
      bug, fixed in subsequent PCRE releases).

PH/54 Applied Robert Bannocks' patch to avoid a problem with references that
      arises when using the Solaris LDAP libraries (but not with OpenLDAP).

PH/55 Check for a ridiculously long file name in exim_dbmbuild.


Exim version 4.63
-----------------

SC/01 Use a glob alias rather than an array ref in eximstats generated
      parser. This improves both readability and performance.

SC/02 Collect SpamAssassin and rejection statistics in eximstats.
      Don't display local sender or destination tables in eximstats unless
      there is data to show.
      Added average volumes into the eximstats top table text output.

SC/03 Collect data on the number of addresses (recipients) as well
      as the number of messages in eximstats.

TF/01 Correct an error in the documentation for the redirect router. Exim
      does (usually) call initgroups() when daemonizing.

TF/02 Call initgroups() when dropping privilege in exim.c, so that Exim runs
      with consistent privilege compared to when running as a daemon.

TF/03 Note in the spec that $authenticated_id is not set for local
      submissions from trusted users.

TF/04 The ratelimit per_rcpt option now works correctly in acl_not_smtp.
      Thanks to Dean Brooks <dean@iglou.com> for the patch.

TF/05 Make it easier to get SMTP authentication and TLS/SSL support working
      by adding some example configuration directives to the default
      configuration file. A little bit of work is required to uncomment the
      directives and define how usernames and passwords are checked, but
      there is now a framework to start from.

PH/01 Added #define LDAP_DEPRECATED 1 to ldap.c because some of the "old"
      functions that Exim currently uses aren't defined in ldap.h for OpenLDAP
      without this. I don't know how relevant this is to other LDAP libraries.

PH/02 Add the verb name to the "unknown ACL verb" error.

PH/03 Magnus Holmgren's patch for filter_prepend_home.

PH/03 Fixed Bugzilla #101: macro definition between ACLs doesn't work.

PH/04 Applied Magnus Holmgren's patch to fix Bugzilla #98: transport's home
      directory not expanded when it should be if an expanded home directory
      was set for the address (which is overridden by the transport).

PH/05 Applied Alex Kiernan's patch to fix Bugzilla #99: a problem with
      libradius.

PH/06 Added acl_not_smtp_start, based on Johannes Berg's patch, and set the
      bit to forbid control=suppress_local_fixups in the acl_not_smtp ACL,
      because it is too late at that time, and has no effect.

PH/07 Changed ${quote_pgsql to quote ' as '' instead of \' because of a
      security issue with \' (bugzilla #107). I could not use the
      PQescapeStringConn() function, because it needs a PGconn value as one of
      its arguments.

PH/08 When testing addresses using -bt, indicate those final addresses that
      are duplicates that would not cause an additional delivery. At least one
      person was confused, thinking that -bt output corresponded to deliveries.
      (Suppressing duplicates isn't a good idea as you lose the information
      about possibly different redirections that led to the duplicates.)

PH/09 Applied patch from Erik to use select() instead of poll() in spam.c on
      systems where poll() doesn't work, in particular OS X.

PH/10 Added more information to debugging output for retry time not reached.

PH/11 Applied patch from Arkadiusz Miskiewicz to apply a timeout to read
      operations in malware.c.

PH/12 Applied patch from Magnus Holmgren to include the "h" tag in Domain Keys
      signatures.

PH/13 If write_rejectlog was set false when logging was sent to syslog with
      syslog_duplication set false, log lines that would normally be written
      both the the main log and to the reject log were not written to syslog at
      all.

PH/14 In the default configuration, change the use of "message" in ACL warn
      statements to "add_header".

PH/15 Diagnose a filter syntax error for "seen", "unseen", or "noerror" if not
      not followed by a command (e.g. "seen endif").

PH/16 Recognize SMTP codes at the start of "message" in ACLs and after :fail:
      and :defer: in a redirect router. Add forbid_smtp_code to suppress the
      latter.

PH/17 Added extra conditions to the default value of delay_warning_condition
      so that it is now:

        ${if or { \
            { !eq{$h_list-id:$h_list-post:$h_list-subscribe:}{} } \
            { match{$h_precedence:}{(?i)bulk|list|junk} } \
            { match{$h_auto-submitted:}{(?i)auto-generated|auto-replied} } \
            }{no}{yes}}

      The Auto-Submitted: and various List- headers are standardised, whereas I
      don't think Precedence: ever was.

PH/18 Refactored debugging code in route_finduser() to show more information,
      in particular, the error code if getpwnam() issues one.

PH/19 Added PQsetClientEncoding(conn, "SQL_ASCII") to the pgsql code module.
      This is apparently needed in addition to the PH/07 change above to avoid
      any possible encoding problems.

PH/20 Perl can change the locale. Exim was resetting it after a ${perl call,
      but not after initializing Perl.

PH/21 Added a call to PQsetNoticeProcessor() to catch pgsql "notices" and
      output them only if debugging. By default they are written stderr,
      apparently, which is not desirable.

PH/22 Added Alain Williams' LDAP patch to support setting REFERRALS=off on
      queries.

JJ/01 exipick: added --reverse (and -R synonym), --random, --size, --sort and
      --not options

JJ/02 exipick: rewrote --help documentation to hopefully make more clear.

PH/23 Made -oMaa and -oMt work with -bh and -bs to pretend the connection is
      authenticated or an ident call has been made. Suppress the default
      values for $authenticated_id and $authenticated_sender (but permit -oMai
      and -oMas) when testing with -bh.

PH/24 Re-jigged the order of the tests in the default configuration so that the
      tests for valid domains and recipients precede the DNS black list and CSA
      tests, on the grounds that those ones are more expensive.

PH/25 Exim was not testing for a space following SMTP commands such as EHLO
      that require one. Thus, EHLORHUBARB was interpreted as a valid command.
      This bug exists in every version of Exim that I still have, right back to
      0.12.

PH/26 (n)wildlsearch lookups are documented as being done case-insensitively.
      However, an attempt to turn on case-sensitivity in a regex key by
      including (?-i) didn't work because the subject string was already
      lowercased, and the effects were non-intuitive. It turns out that a
      one-line patch can be used to allow (?-i) to work as expected.


Exim version 4.62
-----------------

TF/01 Fix the add_header change below (4.61 PH/55) which had a bug that (amongst
      other effects) broke the use of negated acl sub-conditions.

PH/01 ${readsocket now supports Internet domain sockets (modified John Jetmore
      patch).

PH/02 When tcp-wrappers is called from Exim, it returns only "deny" or "allow".
      "Deny" causes Exim to reject the incoming connection with a 554 error.
      Unfortunately, if there is a major crisis, such as a disk failure,
      tcp-wrappers gives "deny", whereas what one would like would be some
      kind of temporary error. A kludge has been added to help with this.
      Before calling hosts_ctl(), errno is set zero. If the result is "deny", a
      554 error is used if errno is still zero or contains ENOENT (which occurs
      if either of the /etc/hosts.{allow,deny} files is missing). Otherwise, a
      451 error is used.

PH/03 Add -lutil to the default FreeBSD LIBS setting.

PH/04 Change PH/19 for 4.61 was too wide. It should not be applied to host
      errors. Otherwise a message that provokes a temporary error (when other
      messages do not) can cause a whole host to time out.

PH/05 Batch deliveries by appendfile and pipe transports did not work when the
      addresses were routed directly to files or pipes from a redirect router.
      File deliveries just didn't batch; pipe deliveries might have suffered
      odd errors.

PH/06 A failure to get a lock for a hints database would erroneously always say
      "Failed to get write lock", even when it was really a read lock.

PH/07 The appendfile transport was creating MBX lock files with a fixed mode
      of 0600. This has been changed to use the value of the lockfile_mode
      option (which defaults to 0600).

PH/08 Applied small patch from the Sieve maintainer.

PH/09 If maildir_quota_directory_regex was set to exclude (say) the .Trash
      folder from quota calculations, a direct delivery into this folder messed
      up the contents of the maildirsize file. This was because the regex was
      used only to exclude .Trash (or whatever) when the size of the mailbox
      was calculated. There was no check that a delivery was happening into an
      excluded directory. This bug has been fixed by ignoring all quota
      processing for deliveries into excluded directories.

PH/10 Added the maildirfolder_create_regex option to appendfile.


Exim version 4.61
-----------------

PH/01 The code for finding all the local interface addresses on a FreeBSD
      system running IPv6 was broken. This may well have applied to all BSD
      systems, as well as to others that have similar system calls. The broken
      code found IPv4 interfaces correctly, but gave incorrect values for the
      IPv6 interfaces. In particular, ::1 was not found. The effect in Exim was
      that it would not match correctly against @[] and not recognize the IPv6
      addresses as local.

PH/02 The ipliteral router was not recognizing addresses of the form user@
      [ipv6:....] because it didn't know about the "ipv6:" prefix.

PH/03 Added disable_ipv6.

PH/04 Changed $reply_address to use the raw form of the headers instead of the
      decoded form, because it is most often used to construct To: headers
      lines in autoreplies, and the decoded form may well be syntactically
      invalid. However, $reply_address has leading white space removed, and all
      newlines turned into spaces so that the autoreply transport does not
      grumble.

PH/05 If group was specified without a user on a router, and no group or user
      was specified on a transport, the group from the router was ignored.

PH/06 Increased the number of ACL variables to 20 of each type, and arranged
      for visible compile-time settings that can be used to change these
      numbers, for those that want even more. Backwards compatibility with old
      spool files has been maintained. However, going back to a previous Exim
      release will lost any variables that are in spool files.

PH/07 Two small changes when running in the test harness: increase delay when
      passing a TCP/IP connection to a new process, in case the original
      process has to generate a bounce, and remove special handling of
      127.0.0.2 (sic), which is no longer necessary.

PH/08 Changed debug output of dbfn_open() flags from numbers to names, so as to
      be the same on different OS.

PH/09 Moved a debug statement in filter processing to avoid a race problem when
      testing.

JJ/01 exipick: fixed bug where -b (brief) output option showed "Vars:"
      whether --show-vars was specified or not

JJ/02 exipick: Added support for new ACL variable spool format introduced
      in 4.61-PH/06

PH/10 Fixed another bug related to PH/04 above: if an incoming message had a
      syntactically invalid From: or Reply-to: line, and a filter used this to
      generate an autoreply, and therefore failed to obtain an address for the
      autoreply, Exim could try to deliver to a non-existent relative file
      name, causing unrelated and misleading errors. What now happens is that
      it logs this as a hard delivery error, but does not attempt to create a
      bounce message.

PH/11 The exinext utility has a -C option for testing purposes, but although
      the given file was scanned by exinext itself; it wasn't being passed on
      when Exim was called.

PH/12 In the smtp transport, treat an explicit ECONNRESET error the same as
      an end-of-file indication when reading a command response.

PH/13 Domain literals for IPv6 were not recognized unless IPv6 support was
      compiled. In many other places in Exim, IPv6 addresses are always
      recognized, so I have changed this. It also means that IPv4 domain
      literals of the form [IPV4:n.n.n.n] are now always recognized.

PH/14 When a uid/gid is specified for the queryprogram router, it cannot be
      used if the router is not running as root, for example, when verifying at
      ACL time, or when using -bh. The debugging output from this situation was
      non-existent - all you got was a failure to exec. I have made two
      changes:

      (a) Failures to set uid/gid, the current directory, or a process leader
          in a subprocess such as that created by queryprogram now generate
          suitable debugging output when -d is set.

      (b) The queryprogram router detects when it is not running as root,
          outputs suitable debugging information if -d is set, and then runs
          the subprocess without attempting to change uid/gid.

PH/15 Minor change to Makefile for building test_host (undocumented testing
      feature).

PH/16 As discussed on the list in Nov/Dec: Exim no longer looks at the
      additional section of a DNS packet that returns MX or SRV records.
      Instead, it always explicitly searches for A/AAAA records. This avoids
      major problems that occur when a DNS server includes only records of one
      type (A or AAAA) in an MX/SRV packet. A byproduct of this change has
      fixed another bug: if SRV records were looked up and the corresponding
      address records were *not* found in the additional section, the port
      values from the SRV records were lost.

PH/17 If a delivery to a pipe, file, or autoreply was deferred, Exim was not
      using the correct key (the original address) when searching the retry
      rules in order to find which one to use for generating the retry hint.

PH/18 If quota_warn_message contains a From: header, Exim now refrains from
      adding the default one. Similarly, if it contains a Reply-To: header, the
      errors_reply_to option, if set, is not used.

PH/19 When calculating a retry time, Exim used to measure the "time since
      failure" by looking at the "first failed" field in the retry record. Now
      it does not use this if it is later than than the arrival time of the
      message. Instead it uses the arrival time. This makes for better
      behaviour in cases where some deliveries succeed, thus re-setting the
      "first failed" field. An example is a quota failure for a huge message
      when small messages continue to be delivered. Without this change, the
      "time since failure" will always be short, possible causing more frequent
      delivery attempts for the huge message than are intended.
      [Note: This change was subsequently modified - see PH/04 for 4.62.]

PH/20 Added $auth1, $auth2, $auth3 to contain authentication data (as well as
      $1, $2, $3) because the numerical variables can be reset during some
      expansion items (e.g. "match"), thereby losing the authentication data.

PH/21 Make -bV show the size of off_t variables so that the test suite can
      decide whether to run tests for quotas > 2G.

PH/22 Test the values given for quota, quota_filecount, quota_warn_threshold,
      mailbox_size, and mailbox_filecount in the appendfile transport. If a
      filecount value is greater than 2G or if a quota value is greater than 2G
      on a system where the size of off_t is not greater than 4, a panic error
      is given.

PH/23 When a malformed item such as 1.2.3/24 appears in a host list, it can
      never match. The debug and -bh output now contains an explicit error
      message indicating a malformed IPv4 address or mask.

PH/24 An host item such as 1.2.3.4/abc was being treated as the IP address
      1.2.3.4 without a mask. Now it is not recognized as an IP address, and
      PH/23 above applies.

PH/25 Do not write to syslog when running in the test harness. The only
      occasion when this arises is a failure to open the main or panic logs
      (for which there is an explicit test).

PH/26 Added the /no_tell option to "control=freeze".

PH/27 If a host name lookup failed very early in a connection, for example, if
      the IP address matched host_lookup and the reverse lookup yielded a name
      that did not have a forward lookup, an error message of the form "no IP
      address found for host xxx.xxx.xxx (during SMTP connection from NULL)"
      could be logged. Now it outputs the IP address instead of "NULL".

PH/28 An enabling patch from MH: add new function child_open_exim2() which
      allows the sender and the authenticated sender to be set when
      submitting a message from within Exim. Since child_open_exim() is
      documented for local_scan(), the new function should be too.

PH/29 In GnuTLS, a forced expansion failure for tls_privatekey was not being
      ignored. In both GnuTLS and OpenSSL, an expansion of tls_privatekey that
      results in an empty string is now treated as unset.

PH/30 Fix eximon buffer overflow bug (Bugzilla #73).

PH/31 Added sender_verify_fail logging option.

PH/32 In November 2003, the code in Exim that added an empty Bcc: header when
      needed by RFC 822 but not by RFC 2822 was commented out. I have now
      tidied the source and removed it altogether.

PH/33 When a queue run was abandoned because the load average was too high, a
      log line was always written; now it is written only if the queue_run log
      selector is set. In addition, the log line for abandonment now contains
      information about the queue run such as the pid. This is always present
      in "start" and "stop" lines but was omitted from the "abandon" line.

PH/34 Omit spaces between a header name and the colon in the error message that
      is given when verify = headers_syntax fails (if there are lots of them,
      the message gets confusing).

PH/35 Change the default for dns_check_names_pattern to allow slashes within
      names, as there are now some PTR records that contain slashes. This check
      is only to protect against broken name servers that fall over on strange
      characters, so the fact that it applies to all lookups doesn't matter.

PH/36 Now that the new test suite is complete, we can remove some of the
      special code in Exim that was needed for the old test suite. For example,
      sorting DNS records because real resolvers return them in an arbitrary
      order. The new test suite's fake resolver always returns records in the
      same order.

PH/37 When running in the test harness, use -odi for submitted messages (e.g.
      bounces) except when queue_only is set, to avoid logging races between
      the different processes.

PH/38 Panic-die if .include specifies a non-absolute path.

PH/39 A tweak to the "H" retry rule from its user.

JJ/03 exipick: Removed parentheses from 'next' and 'last' calls that specified
      a label.  They prevented compilation on older perls.

JJ/04 exipick: Refactored code to prevent implicit split to @_ which caused
      a warning to be raised on newish perls.

JJ/05 exipick: Fixed bug where -bpc always showed a count of all messages
      on queue.  Changes to match documented behaviour of showing count of
      messages matching specified criteria.

PH/40 Changed the default ident timeout from 30s to 5s.

PH/41 Added support for the use of login_cap features, on those BSD systems
      that have them, for controlling the resources used by pipe deliveries.

PH/42 The content-scanning code uses fopen() to create files in which to put
      message data. Previously it was not paying any attention to the mode of
      the files. Exim runs with umask(0) because the rest of the code creates
      files with open(), and sets the required mode explicitly. Thus, these
      files were ending up world-writeable. This was not a big issue, because,
      being within the spool directory, they were not world-accessible. I have
      created a function called modefopen, which takes an additional mode
      argument. It sets umask(777), creates the file, chmods it to the required
      mode, then resets the umask. All the relevant calls to fopen() in the
      content scanning code have been changed to use this function.

PH/43 If retry_interval_max is set greater than 24 hours, it is quietly reset
      to 24 hours. This avoids potential overflow problems when processing G
      and H retry rules. I suspect nobody ever tinkers with this value.

PH/44 Added STRIP_COMMAND=/usr/bin/strip to the FreeBSD Makefile.

PH/45 When the plaintext authenticator is running as a client, the server's
      challenges are checked to ensure they are valid base64 strings. By
      default, the authentication attempt is cancelled if an invalid string is
      received. Setting client_ignore_invalid_base64 true ignores these errors.
      The decoded challenge strings are now placed in $auth1, $auth2, etc. as
      they are received. Thus, the responses can be made to depend on the
      challenges. If an invalid string is ignored, an empty string is placed in
      the variable.

PH/46 Messages that are created by the autoreply transport now contains a
      References: header, in accordance with RFCs 2822 and 3834.

PH/47 Added authenticated_sender_force to the smtp transport.

PH/48 The ${prvs expansion was broken on systems where time_t was long long.

PH/49 Installed latest patch from the Sieve maintainer.

PH/50 When an Exim quota was set without a file count quota, and mailbox_size
      was also set, the appendfile transport was unnecessarily scanning a
      directory of message files (e.g. for maildir delivery) to find the count
      of files (along with the size), even though it did not need this
      information. It now does the scan only if it needs to find either the
      size of the count of files.

PH/51 Added ${time_eval: to convert Exim time strings into seconds.

PH/52 Two bugs concerned with error handling when the smtp transport is
      used in LMTP mode:

      (i) Exim was not creating retry information for temporary errors given
      for individual recipients after the DATA command when the smtp transport
      was used in LMTP mode. This meant that they could be retried too
      frequently, and not timed out correctly.

      (ii) Exim was setting the flag that allows error details to be returned
      for LMTP errors on RCPT commands, but not for LMTP errors for individual
      recipients that were returned after the DATA command.

PH/53 This is related to PH/52, but is more general: for any failing address,
      when detailed error information was permitted to be returned to the
      sender, but the error was temporary, then after the final timeout, only
      "retry timeout exceeded" was returned. Now it returns the full error as
      well as "retry timeout exceeded".

PH/54 Added control=allow_auth_unadvertised, as it seems there are clients that
      do this, and (what is worse) MTAs that accept it.

PH/55 Added the add_header modified to ACLs. The use of "message" with "warn"
      will now be deprecated.

PH/56 New os.c-cygwin from the Cygwin maintainer.

JJ/06 exipick: added --unsorted option to allow unsorted output in all output
      formats (previously only available in exim formats via -bpr, -bpru,
      and -bpra.  Now also available in native and exiqgrep formats)

JJ/07 exipick: added --freeze and --thaw options to allow faster interaction
      with very large, slow to parse queues

JJ/08 exipick: added ! as generic prefix to negate any criteria format

JJ/09 exipick: miscellaneous performance enhancements (~24% improvements)

PH/57 Tidies in SMTP dialogue display in debug output: (i) It was not showing
      responses to authentication challenges, though it was showing the
      challenges; (ii) I've removed the CR characters from the debug output for
      SMTP output lines.

PH/58 Allow for the insertion of a newline as well as a space when a string
      is turned into more than one encoded-word during RFC 2047 encoding. The
      Sieve code now uses this.

PH/59 Added the following errors that can be detected in retry rules: mail_4xx,
      data_4xx, lost_connection, tls_required.

PH/60 When a VRFY deferred or FAILED, the log message rather than the user
      message was being sent as an SMTP response.

PH/61 Add -l and -k options to exicyclog.

PH/62 When verifying, if an address was redirected to one new address, so that
      verification continued, and the new address failed or deferred after
      having set something in $address_data, the value of $address_data was not
      passed back to the ACL. This was different to the case when no
      redirection occurred. The value is now passed back in both cases.

PH/63 Changed the macro HAVE_LOGIN_CAP (see PH/41 for this release above) to
      HAVE_SETCLASSRESOURCES because there are different APIs in use that all
      use login_cap.h, so on its own it isn't the distinguishing feature. The
      new name refers directly to the setclassresources() function.

PH/65 Added configuration files for NetBSD3.

PH/66 Updated OS/Makefile-HP-UX for gcc 4.1.0 with HP-UX 11.

PH/67 Fixed minor infelicity in the sorting of addresses to ensure that IPv6
      is preferred over IPv4.

PH/68 The bounce_return_message and bounce_return_body options were not being
      honoured for bounces generated during the reception of non-SMTP messages.
      In particular, this applied to messages rejected by the ACL. This bug has
      been fixed. However, if bounce_return_message is true and bounce_return_
      body is false, the headers that are returned for a non-SMTP message
      include only those that have been read before the error was detected.
      (In the case of an ACL rejection, they have all been read.)

PH/69 The HTML version of the specification is now built in a directory called
      spec_html instead of spec.html, because the latter looks like a path with
      a MIME-type, and this confuses some software.

PH/70 Catch two compiler warnings in sieve.c.

PH/71 Fixed an obscure and subtle bug (thanks Alexander & Matthias). The
      function verify_get_ident() calls ip_connect() to connect a socket, but
      if the "connect()" function timed out, ip_connect() used to close the
      socket. However, verify_get_ident() also closes the socket later, and in
      between Exim writes to the log, which may get opened at this point. When
      the socket was closed in ip_connect(), the log could get the same file
      descriptor number as the socket. This naturally causes chaos. The fix is
      not to close the socket in ip_connect(); the socket should be closed by
      the function that creates it. There was only one place in the code where
      this was missing, in the iplookup router, which I don't think anybody now
      uses, but I've fixed it anyway.

PH/72 Make dns_again_means_nonexist apply to lookups using gethostbyname() as
      well as to direct DNS lookups. Otherwise the handling of names in host
      lists is inconsistent and therefore confusing.


Exim version 4.60
-----------------

PH/01 Two changes to the default runtime configuration:

      (1) Move the checks for relay_from_hosts and authenticated clients from
          after to before the (commented out) DNS black list checks.

      (2) Add control=submission to the relay_from_hosts and authenticated
          clients checks, on the grounds that messages accepted by these
          statements are most likely to be submissions.

PH/02 Several tidies to the handling of ${prvs and ${prvscheck:

      (1) Generate an error if the third argument for the ${prvs expansion is
          not a single digit.

      (2) Treat a missing third argument of ${prvscheck as if it were an empty
          string.

      (3) Reset the variables that are obtained from the first argument of
          ${prvscheck and used in the second argument before leaving the code,
          because their memory is reclaimed, so using them afterwards may do
          silly things.

      (4) Tidy up the code for expanding the arguments of ${prvscheck one by
          one (it's much easier than Tom thought :-).

      (5) Because of (4), we can now allow for the use of $prvscheck_result
          inside the third argument.

PH/03 For some reason, the default setting of PATH when running a command from
      a pipe transport was just "/usr/bin". I have changed it to
      "/bin:/usr/bin".

PH/04 SUPPORT_TRANSLATE_IP_ADDRESS and MOVE_FROZEN_MESSAGES did not cause
      anything to be listed in the output from -bV.

PH/05 When a filter generated an autoreply, the entire To: header line was
      quoted in the delivery log line, like this:

        => >A.N.Other <ano@some.domain> <original@ddress> ...

      This has been changed so that it extracts the operative address. There
      may be more than one such address. If so, they are comma-separated, like
      this:

        => >ano@some.domain,ona@other.domain <original@ddress> ...

PH/06 When a client host used a correct literal IP address in a HELO or EHLO
      command, (for example, EHLO [1.2.3.4]) and the client's IP address was
      not being looked up in the rDNS to get a host name, Exim was showing the
      IP address twice in Received: lines, even though the IP addresses were
      identical. For example:

        Received: from [1.2.3.4] (helo=[1.2.3.4])

      However, if the real host name was known, it was omitting the HELO data
      if it matched the actual IP address. This has been tidied up so that it
      doesn't show the same IP address twice.

PH/07 When both +timestamp and +memory debugging was on, the value given by
      $tod_xxx expansions could be wrong, because the tod_stamp() function was
      called by the debug printing, thereby overwriting the timestamp buffer.
      Debugging no longer uses the tod_stamp() function when +timestamp is set.

PH/08 When the original message was included in an autoreply transport, it
      always said "this is a copy of the message, including all the headers",
      even if body_only or headers_only was set. It now gives an appropriate
      message.

PH/09 Applied a patch from the Sieve maintainer which:

      o  fixes some comments
      o  adds the (disabled) notify extension core
      o  adds some debug output for the result of if/elsif tests
      o  points to the current vacation draft in the documentation
         and documents the missing references header update

      and most important:

      o  fixes a bug in processing the envelope test (when testing
         multiple envelope elements, the last element determined the
         result)

PH/10 Exim was violating RFC 3834 ("Recommendations for Automatic Responses to
      Electronic Mail") by including:

        Auto-submitted: auto-generated

      in the messages that it generates (bounce messages and others, such as
      warnings). In the case of bounce messages for non-SMTP messages, there was
      also a typo: it was using "Auto_submitted" (underscore instead of
      hyphen). Since every message generated by Exim is necessarily in response
      to another message, thes have all been changed to:

        Auto-Submitted: auto-replied

      in accordance with these statements in the RFC:

        The auto-replied keyword:

        -  SHOULD be used on messages sent in direct response to another
           message by an automatic process,

        -  MUST NOT be used on manually-generated messages,

        -  MAY be used on Delivery Status Notifications (DSNs) and Message
           Disposition Notifications (MDNs),

        -  MUST NOT be used on messages generated by automatic or periodic
           processes, except for messages which are automatic responses to
           other messages.

PH/11 Added "${if def:sender_address {(envelope-from <$sender_address>)\n\t}}"
      to the default Received: header definition.

PH/12 Added log selector acl_warn_skipped (default on).

PH/13 After a successful wildlsearch lookup, discard the values of numeric
      variables because (a) they are in the wrong storage pool and (b) even if
      they were copied, it wouldn't work properly because of the caching.

PH/14 Add check_rfc2047_length to disable enforcement of RFC 2047 length
      checking when decoding. Apparently there are clients that generate
      overlong encoded strings. Why am I not surprised?

PH/15 If the first argument of "${if match_address" was not empty, but did not
      contain an "@" character, Exim crashed. Now it writes a panic log message
      and treats the condition as false.

PH/16 In autoreply, treat an empty string for "once" the same as unset.

PH/17 A further patch from the Sieve maintainer: "Introduce the new Sieve
      extension "envelope-auth".  The code is finished and in agreement with
      other implementations, but there is no documentation so far and in fact,
      nobody wrote the draft yet.  This extension is currently #undef'ed, thus
      not changing the active code.

      Print executed "if" and "elsif" statements when debugging is used. This
      helps a great deal to understand what a filter does.

      Document more things not specified clearly in RFC3028.  I had all this
      sorted out, when out of a sudden new issues came to my mind.  Oops."

PH/18 Exim was not recognizing the "net-" search type prefix in match_ip lists
      (Bugzilla #53).

PH/19 Exim expands the IPv6 address given to -bh to its full non-abbreviated
      canonical form (as documented). However, after a host name lookup from
      the IP address, check_host() was doing a simple string comparison with
      addresses acquired from the DNS when checking that the found name did
      have the original IP as one of its addresses. Since any found IPv6
      addresses are likely to be in abbreviated form, the comparison could
      fail. Luckily, there already exists a function for doing the comparison
      by converting both addresses to binary, so now that is used instead of
      the text comparison.

PH/20 There was another similar case to PH/19, when a complete host name was
      given in a host list; looking up its IP address could give an abbreviated
      form, whereas the current host's name might or might not be abbreviated.
      The same fix has been applied.


Exim version 4.54
-----------------

PH/01 The ${base62: operator adjusted itself to base 36 when BASE_62 was
      set to 36 (for Darwin and Cygwin), but the ${base62d: operator did not.
      It now does.

PH/02 Two minor problems detected in Cygwin: the os.{c,h} files had lost */ on
      the CVS lines, and there was a missing #if HAVE_IPV6 in host.c.

PH/03 Typo: missing ".o" in src/pcre/Makefile.

PH/04 Tighten up "personal" tests: Instead of testing for any "List-"
      header line, restrict the check to what is listed in RFCs 2369 and 2929.
      Also, for "Auto-Submitted", treat anything other than "no" as
      non-personal, in accordance with RFC 3834. (Previously it treated
      anything starting "auto-" as non-personal.)

TF/01 The control=submission/name=... option had a problem with syntax
      errors if the name included a slash character. The /name= option
      now slurps the rest of the string, so it can include any characters
      but it must come last in the list of options (after /sender_retain
      or /domain=).

PH/05 Some modifications to the interface to the fake nameserver for the new
      testing suite.



Exim version 4.53
-----------------

TK/01 Added the "success_on_redirect" address verification option. See
      NewStuff for rationale and an example.

PH/01 Added support for SQLite, basic code supplied by David Woodhouse.

PH/02 Patch to exigrep to allow it to work on syslog lines.

PH/03 When creating an mbox file for a virus/spam scan, use fseek() instead of
      fread() to skip over the body file's header line, because in Cygwin the
      header line is locked and is inaccessible.

PH/04 Added $message_exim_id, ultimately to replace $message_id (they will both
      co-exist for some time) to make it clear that it is the Exim ID that is
      referenced, not the Message-ID: header line.

PH/05 Replaced all Tom's calls to snprintf() with calls to the internal
      string_format() function, because snprintf() does not exist on all
      operating systems.

PH/06 The use of forbid_filter_existstest now also locks out the use of the
      ${stat: expansion item.

PH/07 Changed "SMTP protocol violation: synchronization error" into "SMTP
      protocol synchronization error", to keep the pedants happy.

PH/08 Arrange for USE_INET_NTOA_FIX to be set in config.h for AIX systems as
      well as for IRIX systems, when gcc is being used. See the host.c source
      file for comments.

PH/09 Installed latest Cygwin configuration files from the Cygwin maintainer.

PH/10 Named domain lists were not working if used in a queue_smtp_domains
      setting.

PH/11 Added support for the IGNOREQUOTA extension to LMTP, both to the lmtp
      transport and to the smtp transport in LMTP mode.

TK/02 Remove one case of BASE64 error detection FTTB (undocumented anyway).

PH/12 There was a missing call to search_tidyup() before the fork() in rda.c to
      run a filter in a subprocess. This could lead to confusion in subsequent
      lookups in the parent process. There should also be a search_tidyup() at
      the end of the subprocess.

PH/13 Previously, if "verify = helo" was set in an ACL, the condition was true
      only if the host matched helo_try_verify_hosts, which caused the
      verification to occur when the EHLO/HELO command was issued. The ACL just
      tested the remembered result. Now, if a previous verification attempt has
      not happened, "verify = helo" does it there and then.

JJ/01 exipick: added $message_exim_id variable (see 4.53-PH/04)

TK/03 Fix log output including CR from clamd.

PH/14 A reference to $reply_address when Reply-to: was empty and From: did not
      exist provoked a memory error which could cause a segfault.

PH/15 Installed PCRE 6.2

PH/17 Defined BIND_8_COMPAT in the Darwin os.h file.

PH/18 Reversed 4.52/PH/17 because the HP-UX user found it wasn't the cause
      of the problem. Specifically, suggested +O2 rather than +O1 for the
      HP-UX compiler.

PH/19 Added sqlite_lock_timeout option (David Woodhouse's patch).

PH/20 If a delivery was routed to a non-standard port by means of an SRV
      record, the port was not correctly logged when the outgoing_port log
      selector was set (it logged the transort's default port).

PH/21 Added support for host-specific ports to manualroute, queryprogram,
      fallback_hosts, and "hosts" in the smtp transport.

PH/22 If the log selector "outgoing_port" is set, the port is now also given on
      host errors such as "Connection refused".

PH/23 Applied a patch to fix problems with exim-4.52 while doing radius
      authentication with radiusclient 0.4.9:

      - Error returned from rc_read_config was caught wrongly
      - Username/password not passed on to radius server due to wrong length.

      The presumption is that some radiusclient API changes for 4.51/PH/17
      were not taken care of correctly. The code is still untested by me (my
      Linux distribution still has 0.3.2 of radiusclient), but it was
      contributed by a Radius user.

PH/24 When doing a callout, the value of $domain wasn't set correctly when
      expanding the "port" option of the smtp transport.

TK/04 MIME ACL: Fix buffer underrun that occurs when EOF condition is met
      while reading a MIME header. Thanks to Tom Hughes for a patch.

PH/24 Include config.h inside local_scan.h so that configuration settings are
      available.

PH/25 Make $smtp_command_argument available after all SMTP commands. This means
      that in an ACL for RCPT (for example), you can examine exactly what was
      received.

PH/26 Exim was recognizing IPv6 addresses of the form [IPv6:....] in EHLO
      commands, but it was not correctly comparing the address with the actual
      client host address. Thus, it would show the EHLO address in Received:
      header lines when this was not necessary.

PH/27 Added the % operator to ${eval:}.

PH/28 Exim tries to create and chdir to its spool directory when it starts;
      it should be ignoring failures (because with -C, for example, it has lost
      privilege). It wasn't ignoring creation failures other than "already
      exists".

PH/29 Added "crypteq" to the list of supported features that Exim outputs when
      -bV or -d is used.

PH/30 Fixed (presumably very longstanding) bug in exim_dbmbuild: if it failed
      because an input line was too long, either on its own, or by virtue of
      too many continuations, the temporary file was not being removed, and the
      return code was incorrect.

PH/31 Missing "BOOL" in function definition in filtertest.c.

PH/32 Applied Sieve patches from the maintainer.

TK/05 Domainkeys: Accomodate for a minor API change in libdomainkeys 0.67.

PH/33 Added "verify = not_blind".

PH/34 There are settings for CHOWN_COMMAND and MV_COMMAND that can be used in
      Local/Makefile (with some defaults set). These are used in built scripts
      such as exicyclog, but they have never been used in the exim_install
      script (though there are many overriding facilities there). I have
      arranged that the exim_install script now takes note of these two
      settings.

PH/35 Installed configuration files for Dragonfly.

PH/36 When a locally submitted message by a trusted user did not contain a
      From: header, and the sender address was obtained from -f or from an SMTP
      MAIL command, and the trusted user did not use -F to supply a sender
      name, $originator_name was incorrectly used when constructing a From:
      header. Furthermore, $originator_name was used for submission mode
      messages from external hosts without From: headers in a similar way,
      which is clearly wrong.

PH/37 Added control=suppress_local_fixups.

PH/38 When log_selector = +received_sender was set, and the addition of the
      sender made the log line's construction buffer exactly full, or one byte
      less than full, an overflow happened when the terminating "\n" was
      subsequently added.

PH/39 Added a new log selector, "unknown_in_list", which provokes a log entry
      when the result of a list match is failure because a DNS lookup failed.

PH/40 RM_COMMAND is now used in the building process.

PH/41 Added a "distclean" target to the top-level Makefile; it deletes all
      the "build-* directories that it finds.

PH/42 (But a TF fix): In a domain list, Exim incorrectly matched @[] if the IP
      address in a domain literal was a prefix of an interface address.

PH/43 (Again a TF fix): In the dnslookup router, do not apply widen_domains
      when verifying a sender address, unless rewrite_headers is false.

PH/44 Wrote a long comment about why errors_to addresses are verified as
      recipients, not senders.

TF/01 Add missing LIBS=-lm to OS/Makefile-OpenBSD which was overlooked when
      the ratelimit ACL was added.

PH/45 Added $smtp_command for the full command (cf $smtp_command_argument).

PH/46 Added extra information about PostgreSQL errors to the error string.

PH/47 Added an interface to a fake DNS resolver for use by the new test suite,
      avoiding the need to install special zones in a real server. This is
      backwards compatible; if it can't find the fake resolver, it drops back.
      Thus, both old and new test suites can be run.

TF/02 Added util/ratelimit.pl

TF/03 Minor fix to the ratelimit code to improve its behaviour in case the
      clock is set back in time.

TF/04 Fix the ratelimit support in exim_fixdb. Patch provided by Brian
      Candler <B.Candler@pobox.com>.

TF/05 The fix for PH/43 was not completely correct; widen_domains is always
      OK for addresses that are the result of redirections.

PH/48 A number of further additions for the benefit of the new test suite,
      including a fake gethostbyname() that interfaces to the fake DNS resolver
      (see PH/47 above).

TF/06 The fix for widen_domains has also been applied to qualify_single and
      search_parents which are the other dnslookup options that can cause
      header rewrites.

PH/49 Michael Haardt's randomized retrying, but as a separate retry parameter
      type ("H").

PH/50 Make never_users, trusted_users, admin_groups, trusted_groups expandable.

TF/07 Exim produced the error message "an SRV record indicated no SMTP
      service" if it encountered an MX record with an empty target hostname.
      The message is now "an MX or SRV record indicated no SMTP service".

TF/08 Change PH/13 introduced the possibility that verify=helo may defer,
      if the DNS of the sending site is misconfigured. This is quite a
      common situation. This change restores the behaviour of treating a
      helo verification defer as a failure.

PH/51 If self=fail was set on a router, the bounce message did not include the
      actual error message.


Exim version 4.52
-----------------

TF/01 Added support for Client SMTP Authorization. See NewStuff for details.

PH/01 When a transport filter timed out in a pipe delivery, and the pipe
      command itself ended in error, the underlying message about the transport
      filter timeout was being overwritten with the pipe command error. Now the
      underlying error message should be appended to the second error message.

TK/01 Fix poll() being unavailable on Mac OSX 10.2.

PH/02 Reduce the amount of output that "make" produces by default. Full output
      can still be requested.

PH/03 The warning log line about a condition test deferring for a "warn" verb
      was being output only once per connection, rather than after each
      occurrence (because it was using the same function as for successful
      "warn" verbs). This seems wrong, so I have changed it.

TF/02 Two buglets in acl.c which caused Exim to read a few bytes of memory that
      it should not have, which might have caused a crash in the right
      circumstances, but probably never did.

PH/04 Installed a modified version of Tony Finch's patch to make submission
      mode fix the return path as well as the Sender: header line, and to
      add a /name= option so that you can make the user's friendly name appear
      in the header line.

TF/03 Added the control = fakedefer ACL modifier.

TF/04 Added the ratelimit ACL condition. See NewStuff for details. Thanks to
      Mark Lowes for thorough testing.

TK/02 Rewrote SPF support to work with libspf2 versions >1.2.0.

TK/03 Merged latest SRS patch from Miles Wilton.

PH/05 There's a shambles in IRIX6 - it defines EX_OK in unistd.h which conflicts
      with the definition in sysexits.h (which is #included earlier).
      Fortunately, Exim does not actually use EX_OK. The code used to try to
      preserve the sysexits.h value, by assuming that macro definitions were
      scanned for macro replacements. I have been disabused of this notion,
      so now the code just undefines EX_OK before #including unistd.h.

PH/06 There is a timeout for writing blocks of data, set by, e.g. data_timeout
      in the smtp transport. When a block could not be written in a single
      write() function, the timeout was being re-applied to each part-write.
      This seems wrong - if the receiver was accepting one byte at a time it
      would take for ever. The timeout is now adjusted when this happens. It
      doesn't have to be particularly precise.

TK/04 Added simple SPF lookup method in EXPERIMENTAL_SPF. See NewStuff for
      details. Thanks to Chris Webb <chris@arachsys.com> for the patch!

PH/07 Added "fullpostmaster" verify option, which does a check to <postmaster>
      without a domain if the check to <postmaster@domain> fails.

SC/01 Eximstats: added -xls and the ability to specify output files
     (patch written by Frank Heydlauf).

SC/02 Eximstats: use FileHandles for outputting results.

SC/03 Eximstats: allow any combination of xls, txt, and html output.

SC/04 Eximstats: fixed display of large numbers with -nvr option

SC/05 Eximstats: fixed merging of reports with empty tables.

SC/06 Eximstats: added the -include_original_destination flag

SC/07 Eximstats: removed tabs and trailing whitespace.

TK/05 Malware: Improve on aveserver error handling. Patch from Alex Miller.

TK/06 MBOX spool code: Add real "From " MBOX separator line
      so the .eml file is really in mbox format (even though
      most programs do not really care). Patch from Alex Miller.

TK/07 MBOX spool code: Add X-Envelope-From: and X-Envelope-To: headers.
      The latter is generated from $received_to and is only set if the
      message has one envelope recipient. SA can use these headers,
      obviously out-of-the-box. Patch from Alex Miller.

PH/08 The ${def test on a variable was returning false if the variable's
      value was "0", contrary to what the specification has always said!
      The result should be true unless the variable is empty.

PH/09 The syntax error of a character other than { following "${if
      def:variable_name" (after optional whitespace) was not being diagnosed.
      An expansion such as ${if def:sender_ident:{xxx}{yyy}} in which an
      accidental colon was present, for example, could give incorrect results.

PH/10 Tidied the code in a number of places where the st_size field of a stat()
      result is used (not including appendfile, where other changes are about
      to be made).

PH/11 Upgraded appendfile so that quotas larger than 2G are now supported.
      This involved changing a lot of size variables from int to off_t. It
      should work with maildirs and everything.

TK/08 Apply fix provided by Michael Haardt to prevent deadlock in case of
      spamd dying while we are connected to it.

TF/05 Fixed a ${extract error message typo reported by Jeremy Harris
      <jgh@wizmail.org>

PH/12 Applied Alex Kiernan's patch for the API change for the error callback
      function for BDB 4.3.

PH/13 Changed auto_thaw such that it does not apply to bounce messages.

PH/14 Imported PCRE 6.0; this was more than just a trivial operation because
      the sources for PCRE have been re-arranged and more files are now
      involved.

PH/15 The code I had for printing potentially long long variables in PH/11
      above was not the best (it lost precision). The length of off_t variables
      is now inspected at build time, and an appropriate printing format (%ld
      or %lld) is chosen and #defined by OFF_T_FMT. We also define LONGLONG_T
      to be "long long int" or "long int". This is needed for the internal
      formatting function string_vformat().

PH/16 Applied Matthew Newton's patch to exicyclog: "If log_file_path is set in
      the configuration file to be ":syslog", then the script "guesses" where
      the logs files are, rather than using the compiled in default. In our
      case the guess is not the same as the compiled default, so the script
      suddenly stopped working when I started to use syslog. The patch checks
      to see if log_file_path is "". If so, it attempts to read it from exim
      with no configuration file to get the compiled in version, before it
      falls back to the previous guessing code."

TK/09 Added "prvs" and "prvscheck" expansion items. These help a lot with
      implementing BATV in an Exim configuration. See NewStuff for the gory
      details.

PH/17 Applied Michael Haardt's patch for HP-UX, affecting only the os.h and
      Makefile that are specific to HP-UX.

PH/18 If the "use_postmaster" option was set for a recipient callout together
      with the "random" option, the postmaster address was used as the MAIL
      FROM address for the random test, but not for the subsequent recipient
      test. It is now used for both.

PH/19 Applied Michael Haardt's patch to update Sieve to RFC3028bis. "The
      patch removes a few documentation additions to RFC 3028, because the
      latest draft now contains them. It adds the new en;ascii-case comparator
      and a new error check for 8bit text in MIME parts. Comparator and
      require names are now matched exactly. I enabled the subaddress
      extension, but it is not well tested yet (read: it works for me)."

PH/20 Added macros for time_t as for off_t (see PH/15 above) and used them to
      rework some of the code of TK/09 above to avoid the hardwired use of
      "%lld" and "long long". Replaced the call to snprintf() with a call to
      string_vformat().

PH/21 Added some other messages to those in 4.51/PH/42, namely "All relevant MX
      records point to non-existent hosts", "retry timeout exceeded", and
      "retry time not reached for any host after a long failure period".

PH/22 Fixed some oversights/typos causing bugs when Exim is compiled with
      experimental DomainKeys support:

      (1) The filter variables $n0-$n9 and $sn0-$sn9 were broken.
      (2) On an error such as an illegally used "control", the wrong name for
          the control was given.

      These problems did NOT occur unless DomainKeys support was compiled.

PH/23 Added daemon_startup_retries and daemon_startup_sleep.

PH/24 Added ${if match_ip condition.

PH/25 Put debug statements on either side of calls to EXIM_DBOPEN() for hints
      databases so that it will be absolutely obvious if a crash occurs in the
      DB library. This is a regular occurrence (often caused by mis-matched
      db.h files).

PH/26 Insert a lot of missing (void) casts for functions such as chown(),
      chmod(), fcntl(), sscanf(), and other functions from stdio.h. These were
      picked up on a user's system that detects such things. There doesn't seem
      to be a gcc warning option for this - only an attribute that has to be
      put on the function's prototype. It seems that in Fedora Core 4 they have
      set this on a number of new functions. No doubt there will be more in due
      course.

PH/27 If a dnslookup or manualroute router is set with verify=only, it need not
      specify a transport. However, if an address that was verified by such a
      router was the subject of a callout, Exim crashed because it tried to
      read the rcpt_include_affixes from the non-existent transport. Now it
      just assumes that the setting of that option is false. This bug was
      introduced by 4.51/PH/31.

PH/28 Changed -d+all to exclude +memory, because that information is very
      rarely of interest, but it makes the output a lot bigger. People tend to
      do -d+all out of habit.

PH/29 Removed support for the Linux-libc5 build, as it is obsolete and the
      code in os-type was giving problems when libc.so lives in lib64, like on
      x86_64 Fedora Core.

PH/30 Exim's DNS code uses the original T_xxx names for DNS record times. These
      aren't the modern standard, and it seems that some systems' include files
      don't always have them. Exim was already checking for some of the newer
      ones like T_AAAA, and defining it itself. I've added checks for all the
      record types that Exim uses.

PH/31 When using GnuTLS, if the parameters cache file did not exist, Exim was
      not automatically generating a new one, as it is supposed to. This
      prevented TLS from working. If the file did exist, but contained invalid
      data, a new version was generated, as expected. It was only the case of a
      non-existent file that was broken.

TK/10 Domainkeys: Fix a bug in verification that caused a crash in conjunction
      with a change in libdomainkeys > 0.64.

TK/11 Domainkeys: Change the logic how the "testing" policy flag is retrieved
      from DNS. If the selector record carries the flag, it now has
      precedence over the domain-wide flag.

TK/12 Cleared some compiler warnings related to SPF, SRS and DK code.

PH/32 In mua_wrapper mode, if an smtp transport configuration error (such as
      the use of a port name that isn't defined in /etc/services) occurred, the
      message was deferred as in a normal delivery, and thus remained on the
      spool, instead of being failed because of the mua_wrapper setting. This
      is now fixed, and I tidied up some of the mua_wrapper messages at the
      same time.

SC/08 Eximstats: whilst parsing the mainlog(s), store information about
      the messages in a hash of arrays rather than using individual hashes.
      This is a bit cleaner and results in dramatic memory savings, albeit
      at a slight CPU cost.

SC/09 Eximstats: added the -show_rt<list> and the -show_dt<list> flags
      as requested by Marc Sherman.

SC/10 Eximstats: added histograms for user specified patterns as requested
      by Marc Sherman.

SC/11 Eximstats: v1.43 - bugfix for pattern histograms with -h0 specified.

PH/33 Patch from the Cygwin maintainer to add "b" to all occurences of
      fopen() in the content-scanning modules that did not already have it.


Exim version 4.51
-----------------

TK/01 Added Yahoo DomainKeys support via libdomainkeys. See
      doc/experimental-spec.txt for details. (http://domainkeys.sf.net)

TK/02 Fix ACL "control" statement not being available in MIME ACL.

TK/03 Fix ACL "regex" condition not being available in MIME ACL.

PH/01 Installed a patch from the Sieve maintainer that allows -bf to be used
      to test Sieve filters that use "vacation".

PH/02 Installed a slightly modified version of Nikos Mavrogiannopoulos' patch
      that changes the way the GnuTLS parameters are stored in the cache file.
      The new format can be generated externally. For backward compatibility,
      if the data in the cache doesn't make sense, Exim assumes it has read an
      old-format file, and it generates new data and writes a new file. This
      means that you can't go back to an older release without removing the
      file.

PH/03 A redirect router that has both "unseen" and "one_time" set does not
      work if there are any delivery delays because "one_time" forces the
      parent to be marked "delivered", so its unseen clone is never tried
      again. For this reason, Exim now forbids the simultaneous setting of
      these two options.

PH/04 Change 4.11/85 fixed an obscure bug concerned with addresses that are
      redirected to themselves ("homonym" addresses). Read the long ChangeLog
      entry if you want to know the details. The fix, however, neglected to
      consider the case when local delivery batching is involved. The test for
      "previously delivered" was not happening when checking to see if an
      address could be batched with a previous (undelivered) one; under
      certain circumstances this could lead to multiple deliveries to the same
      address.

PH/05 Renamed the macro SOCKLEN_T as EXIM_SOCKLEN_T because AIX uses SOCKLEN_T
      in its include files, and this causes problems building Exim.

PH/06 A number of "verify =" ACL conditions have no options (e.g. verify =
      header_syntax) but Exim was just ignoring anything given after a slash.
      In particular, this caused confusion with an attempt to use "verify =
      reverse_host_lookup/defer_ok". An error is now given when options are
      supplied for verify items that do not have them. (Maybe reverse_host_
      lookup should have a defer_ok option, but that's a different point.)

PH/07 Increase the size of the buffer for incoming SMTP commands from 512 (as
      defined by RFC 821) to 2048, because there were problems with some AUTH
      commands, and RFC 1869 says the size should be increased for extended
      SMTP commands that take arguments.

PH/08 Added ${dlfunc dynamically loaded function for expansion (code from Tony
      Finch).

PH/09 Previously, an attempt to use ${perl when it wasn't compiled gave an
      "unknown" error; now it says that the functionality isn't in the binary.

PH/10 Added a nasty fudge to try to recognize and flatten LDAP passwords in
      an address' error message when a string expansion fails (syntax or
      whatever). Otherwise the password may appear in the log. Following change
      PH/42 below, there is no longer a chance of it appearing in a bounce
      message.

PH/11 Installed exipick version 20050225.0 from John Jetmore.

PH/12 If the last host in a fallback_hosts list was multihomed, only the first
      of its addresses was ever tried. (Bugzilla bug #2.)

PH/13 If "headers_add" in a transport didn't end in a newline, Exim printed
      the result incorrectly in the debug output. (It correctly added a newline
      to what was transported.)

TF/01 Added $received_time.

PH/14 Modified the default configuration to add an acl_smtp_data ACL, with
      commented out examples of how to interface to a virus scanner and to
      SpamAssassin. Also added commented examples of av_scanner and
      spamd_address settings.

PH/15 Further to TK/02 and TK/03 above, tidied up the tables of what conditions
      and controls are allowed in which ACLs. There were a couple of minor
      errors. Some of the entries in the conditions table (which is a table of
      where they are NOT allowed) were getting very unwieldy; rewrote them as a
      negation of where the condition IS allowed.

PH/16 Installed updated OS/os.c-cygwin from the Cygwin maintainer.

PH/17 The API for radiusclient changed at release 0.4.0. Unfortunately, the
      header file does not have a version number, so I've had to invent a new
      value for RADIUS_LIB_TYPE, namely "RADIUSCLIENTNEW" to request the new
      API. The code is untested by me (my Linux distribution still has 0.3.2 of
      radiusclient), but it was contributed by a Radius user.

PH/18 Installed Lars Mainka's patch for the support of CRL collections in
      files or directories, for OpenSSL.

PH/19 When an Exim process that is running as root has to create an Exim log
      file, it does so in a subprocess that runs as exim:exim so as to get the
      ownership right at creation (otherwise, other Exim processes might see
      the file with the wrong ownership). There was no test for failure of this
      fork() call, which would lead to the process getting stuck as it waited
      for a non-existent subprocess. Forks do occasionally fail when resources
      run out. I reviewed all the other calls to fork(); they all seem to check
      for failure.

PH/20 When checking for unexpected SMTP input at connect time (before writing
      the banner), Exim was not dealing correctly with a non-positive return
      from the read() function. If the client had disconnected by this time,
      the result was a log entry for a synchronization error with an empty
      string after "input=" when read() returned zero. If read() returned -1
      (an event I could not check), uninitialized data bytes were printed.
      There were reports of junk text (parts of files, etc) appearing after
      "input=".

PH/21 Added acl_not_smtp_mime to allow for MIME scanning for non-SMTP messages.

PH/22 Added support for macro redefinition, and (re)definition in between
      driver and ACL definitions.

PH/23 The cyrus_sasl authenticator was expanding server_hostname, but then
      forgetting to use the resulting value; it was using the unexpanded value.

PH/24 The cyrus_sasl authenticator was advertising mechanisms for which it
      hadn't been configured. The fix is from Juergen Kreileder, who
      understands it better than I do:

      "Here's what I see happening with three configured cyrus_sasl
      authenticators configured (plain, login, cram-md5):

      On startup auth_cyrus_sasl_init() gets called for each of these.
      This means three calls to sasl_listmech() without a specified mech_list.
      => SASL tests which mechs of all available mechs actually work
      => three warnings about OTP not working
      => the returned list contains: plain, login, cram-md5, digest-md5, ...

      With the patch, sasl_listmech() also gets called three times.  But now
      SASL's mech_list option is set to the server_mech specified in the the
      authenticator.  Or in other words, the answer from sasl_listmech()
      gets limited to just the mech you're testing for (which is different
      for each call.)
      => the return list contains just 'plain' or 'login', 'cram-md5' or
      nothing depending on the value of ob->server_mech.

      I've just tested the patch: Authentication still works fine,
      unavailable mechs specified in the exim configuration are still
      caught, and the auth.log warnings about OTP are gone."

PH/25 When debugging is enabled, the contents of the command line are added
      to the debugging output, even when log_selector=+arguments is not
      specified.

PH/26 Change scripts/os-type so that when "uname -s" returns just "GNU", the
      answer is "GNU", and only if the return is "GNU/something" is the answer
      "Linux".

PH/27 $acl_verify_message is now set immediately after the failure of a
      verification in an ACL, and so is available in subsequent modifiers. In
      particular, the message can be preserved by coding like this:

         warn  !verify = sender
               set acl_m0 = $acl_verify_message

      Previously, $acl_verify_message was set only while expanding "message"
      and "log_message" when a very denied access.

PH/28 Modified OS/os.c-Linux with

        -#ifndef OS_LOAD_AVERAGE
        +#if !defined(OS_LOAD_AVERAGE) && defined(__linux__)

      to make Exim compile on kfreebsd-gnu. (I'm totally confused about the
      nomenclature these days.)

PH/29 Installed patch from the Sieve maintainer that adds the options
      sieve_useraddress and sieve_subaddress to the redirect router.

PH/30 In these circumstances:
        . Two addresses routed to the same list of hosts;
        . First host does not offer TLS;
        . First host accepts first address;
        . First host gives temporary error to second address;
        . Second host offers TLS and a TLS session is established;
        . Second host accepts second address.
      Exim incorrectly logged both deliveries with the TLS parameters (cipher
      and peerdn, if requested) that were in fact used only for the second
      address.

PH/31 When doing a callout as part of verifying an address, Exim was not paying
      attention to any local part prefix or suffix that was matched by the
      router that accepted the address. It now behaves in the same way as it
      does for delivery: the affixes are removed from the local part unless
      rcpt_include_affixes is set on the transport.

PH/32 Add the sender address, as F=<...>, to the log line when logging a
      timeout during the DATA phase of an incoming message.

PH/33 Sieve envelope tests were broken for match types other than :is. I have
      applied a patch sanctioned by the Sieve maintainer.

PH/34 Change 4.50/80 broke Exim in that it could no longer handle cases where
      the uid or gid is negative. A case of a negative gid caused this to be
      noticed. The fix allows for either to be negative.

PH/35 ACL_WHERE_MIME is now declared unconditionally, to avoid too much code
      clutter, but the tables that are indexed by ACL_WHERE_xxx values had been
      overlooked.

PH/36 The change PH/12 above was broken. Fixed it.

PH/37 Exim used to check for duplicate addresses in the middle of routing, on
      the grounds that routing the same address twice would always produce the
      same answer. This might have been true once, but it is certainly no
      longer true now. Routing a child address may depend on the previous
      routing that produced that child. Some complicated redirection strategies
      went wrong when messages had multiple recipients, and made Exim's
      behaviour dependent on the order in which the addresses were given.

      I have moved the duplicate checking until after the routing is complete.
      Exim scans the addresses that are assigned to local and remote
      transports, and removes any duplicates. This means that more work will be
      done, as duplicates will always all be routed, but duplicates are
      presumably rare, so I don't expect this is of any significance.

      For deliveries to pipes, files, and autoreplies, the duplicate checking
      still happens during the routing process, since they are not going to be
      routed further.

PH/38 Installed a patch from Ian Freislich, with the agreement of Tom Kistner.
      It corrects a timeout issue with spamd. This is Ian's comment: "The
      background is that sometimes spamd either never reads data from a
      connection it has accepted, or it never writes response data. The exiscan
      spam.[ch] uses a 3600 second timeout on spamd socket reads, further, it
      blindly assumes that writes won't block so it may never time out."

PH/39 Allow G after quota size as well as K and M.

PH/40 The value set for $authenticated_id in an authenticator may not contain
      binary zeroes or newlines because the value is written to log lines and
      to spool files. There was no check on this. Now the value is run through
      the string_printing() function so that such characters are converted to
      printable escape sequences.

PH/41 $message_linecount is a new variable that contains the total number of
      lines in the message. Compare $body_linecount, which is the count for the
      body only.

PH/42 Exim no longer gives details of delivery errors for specific addresses in
      bounce and delay warning messages, except in certain special cases, which
      are as follows:

      (a) An SMTP error message from a remote host;
      (b) A message specified in a :fail: redirection;
      (c) A message specified in a "fail" command in a system filter;
      (d) A message specified in a FAIL return from the queryprogram router;
      (e) A message specified by the cannot_route_message router option.

      In these cases only, Exim does include the error details in bounce and
      warning messages. There are also a few cases where bland messages such
      as "unrouteable address" or "local delivery error" are given.

PH/43 $value is now also set for the "else" part of a ${run expansion.

PH/44 Applied patch from the Sieve maintainer: "The vacation draft is still
      being worked on, but at least Exim now implements the latest version to
      play with."

PH/45 In a pipe transport, although a timeout while waiting for the pipe
      process to complete was treated as a delivery failure, a timeout while
      writing the message to the pipe was logged, but erroneously treated as a
      successful delivery. Such timeouts include transport filter timeouts. For
      consistency with the overall process timeout, these timeouts are now
      treated as errors, giving rise to delivery failures by default. However,
      there is now a new Boolean option for the pipe transport called
      timeout_defer, which, if set TRUE, converts the failures into defers for
      both kinds of timeout. A transport filter timeout is now identified in
      the log output.

PH/46 The "scripts/Configure-config.h" script calls "make" at one point. On
      systems where "make" and "gmake" are different, calling "gmake" at top
      level broke things. I've arranged for the value of $(MAKE) to be passed
      from the Makefile to this script so that it can call the same version of
      "make".


A note about Exim versions 4.44 and 4.50
----------------------------------------

Exim 4.50 was meant to be the next release after 4.43. It contains a lot of
changes of various kinds. As a consequence, a big documentation update was
needed. This delayed the release for rather longer than seemed good, especially
in the light of a couple of (minor) security issues. Therefore, the changes
that fixed bugs were backported into 4.43, to create a 4.44 maintenance
release. So 4.44 and 4.50 are in effect two different branches that both start
from 4.43.

I have left the 4.50 change log unchanged; it contains all the changes since
4.43. The change log for 4.44 is below; many of its items are identical to
those for 4.50. This seems to be the most sensible way to preserve the
historical information.


Exim version 4.50
-----------------

 1. Minor wording change to the doc/README.SIEVE file.

 2. Change 4.43/35 introduced a bug: if quota_filecount was set, the
    computation of the current number of files was incorrect.

 3. Closing a stable door: arrange to panic-die if setitimer() ever fails. The
    bug fixed in 4.43/37 would have been diagnosed quickly if this had been in
    place.

 4. Give more explanation in the error message when the command for a transport
    filter fails to execute.

 5. There are several places where Exim runs a non-Exim command in a
    subprocess. The SIGUSR1 signal should be disabled for these processes. This
    was being done only for the command run by the queryprogram router. It is
    now done for all such subprocesses. The other cases are: ${run, transport
    filters, and the commands run by the lmtp and pipe transports.

 6. Added CONFIGURE_GROUP build-time option.

 7. Some older OS have a limit of 256 on the maximum number of file
    descriptors. Exim was using setrlimit() to set 1000 as a large value
    unlikely to be exceeded. Change 4.43/17 caused a lot of logging on these
    systems. I've change it so that if it can't get 1000, it tries for 256.

 8. "control=submission" was allowed, but had no effect, in a DATA ACL. This
    was an oversight, and furthermore, ever since the addition of extra
    controls (e.g. 4.43/32), the checks on when to allow different forms of
    "control" were broken. There should now be diagnostics for all cases when a
    control that does not make sense is encountered.

 9. Added the /retain_sender option to "control=submission".

10. $recipients is now available in the predata ACL (oversight).

11. Tidy the search cache before the fork to do a delivery from a message
    received from the command line. Otherwise the child will trigger a lookup
    failure and thereby defer the delivery if it tries to use (for example) a
    cached ldap connection that the parent has called unbind on.

12. If verify=recipient was followed by verify=sender in a RCPT ACL, the value
    of $address_data from the recipient verification was clobbered by the
    sender verification.

13. The value of address_data from a sender verification is now available in
    $sender_address_data in subsequent conditions in the ACL statement.

14. Added forbid_sieve_filter and forbid_exim_filter to the redirect router.

15. Added a new option "connect=<time>" to callout options, to set a different
    connection timeout.

16. If FIXED_NEVER_USERS was defined, but empty, Exim was assuming the uid 0
    was its contents. (It was OK if the option was not defined at all.)

17. A "Completed" log line is now written for messages that are removed from
    the spool by the -Mrm option.

18. New variables $sender_verify_failure and $recipient_verify_failure contain
    information about exactly what failed.

19. Added -dd to debug only the daemon process.

20. Incorporated Michael Haardt's patch to ldap.c for improving the way it
    handles timeouts, both on the server side and network timeouts. Renamed the
    CONNECT parameter as NETTIMEOUT (but kept the old name for compatibility).

21. The rare case of EHLO->STARTTLS->HELO was setting the protocol to "smtp".
    It is now set to "smtps".

22. $host_address is now set to the target address during the checking of
    ignore_target_hosts.

23. When checking ignore_target_hosts for an ipliteral router, no host name was
    being passed; this would have caused $sender_host_name to have been used if
    matching the list had actually called for a host name (not very likely,
    since this list is usually IP addresses). A host name is now passed as
    "[x.x.x.x]".

24. Changed the calls that set up the SIGCHLD handler in the daemon to use the
    code that specifies a non-restarting handler (typically sigaction() in
    modern systems) in an attempt to fix a rare and obscure crash bug.

25. Narrowed the window for a race in the daemon that could cause it to ignore
    SIGCHLD signals. This is not a major problem, because they are used only to
    wake it up if nothing else does.

26. A malformed maildirsize file could cause Exim to calculate negative values
    for the mailbox size or file count. Odd effects could occur as a result.
    The maildirsize information is now recalculated if the size or filecount
    end up negative.

27. Added HAVE_SYS_STATVFS_H to the os.h file for Linux, as it has had this
    support for a long time. Removed HAVE_SYS_VFS_H.

28. Installed the latest version of exipick from John Jetmore.

29. In an address list, if the pattern was not a regular expression, an empty
    subject address (from a bounce message) matched only if the pattern was an
    empty string. Non-empty patterns were not even tested. This was the wrong
    because it is perfectly reasonable to use an empty address as part of a
    database query. An empty address is now tested by patterns that are
    lookups. However, all the other forms of pattern expect the subject to
    contain a local part and a domain, and therefore, for them, an empty
    address still always fails if the pattern is not itself empty.

30. Exim went into a mad DNS loop when attempting to do a callout where the
    host was specified on an smtp transport, and looking it up yielded more
    than one IP address.

31. Re-factored the code for checking spool and log partition space into a
    function that finds that data and another that does the check. The former
    is then used to implement four new variables: $spool_space, $log_space,
    $spool_inodes, and $log_inodes.

32. The RFC2047 encoding function was originally intended for short strings
    such as real names; it was not keeping to the 75-character limit for
    encoded words that the RFC imposes. It now respects the limit, and
    generates multiple encoded words if necessary. To be on the safe side, I
    have increased the buffer size for the ${rfc2047: expansion operator from
    1024 to 2048 bytes.

33. It is now permitted to omit both strings after an "if" condition; if the
    condition is true, the result is "true". As before, when the second string
    is omitted, a false condition yields an empty string. This makes it less
    cumbersome to write custom ACL and router conditions.

34. Failure to deliver a bounce message always caused it to be frozen, even if
    there was an errors_to setting on the router. The errors_to setting is now
    respected.

35. If an IPv6 address is given for -bh or -bhc, it is now converted to the
    canonical form (fully expanded) before being placed in
    $sender_host_address.

36. The table in the code that translates DNS record types into text (T_A to
    "A" for instance) was missing entries for NS and CNAME. It is just possible
    that this could have caused confusion if both these types were looked up
    for the same domain, because the text type is used as part of Exim's
    per-process caching. But the chance of anyone hitting this buglet seems
    very small.

37. The dnsdb lookup has been extended in a number of ways.

    (1) There is a new type, "zns", which walks up the domain tree until it
        finds some nameserver records. It should be used with care.

    (2) There is a new type, "mxh", which is like "mx" except that it returns
        just the host names, not the priorities.

    (3) It is now possible to give a list of domains (or IP addresses) to be
        looked up. The behaviour when one of the lookups defers can be
        controlled by a keyword.

    (4) It is now possible to specify the separator character for use when
        multiple records are returned.

38. The dnslists ACL condition has been extended: it is now possible to supply
    a list of IP addresses and/or domains to be looked up in a particular DNS
    domain.

39. Added log_selector=+queue_time_overall.

40. When running the queue in the test harness, wait just a tad after forking a
    delivery process, to get repeatability of debugging output.

41. Include certificate and key file names in error message when GnuTLS fails
    to set them up, because the GnuTLS error message doesn't include the name
    of the failing file when there is a problem reading it.

42. Allow both -bf and -bF in the same test run.

43. Did the same fix as 41 above for OpenSSL, which had the same infelicity.

44. The "Exiscan patch" is now merged into the mainline Exim source.

45. Sometimes the final signoff response after QUIT could fail to get
    transmitted in the non-TLS case. Testing !tls_active instead of tls_active
    < 0 before doing a fflush(). This bug looks as though it goes back to the
    introduction of TLS in release 3.20, but "sometimes" must have been rare
    because the tests only now provoked it.

46. Reset the locale to "C" after calling embedded Perl, in case it was changed
    (this can affect the format of dates).

47. exim_tidydb, when checking for the continued existence of a message for
    which it has found a message-specific retry record, was not finding
    messages that were in split spool directories. Consequently, it was
    deleting retry records that should have stayed in existence.

48. Steve fixed some bugs in eximstats.

49. The SPA authentication driver was not abandoning authentication and moving
    on to the next authenticator when an expansion was forced to fail,
    contradicting the general specification for all authenticators. Instead it
    was generating a temporary error. It now behaves as specified.

50. The default ordering of permitted cipher suites for GnuTLS was pessimal
    (the order specifies the preference for clients). The order is now AES256,
    AES128, 3DES, ARCFOUR128.

51. Small patch to Sieve code - explicitly set From: when generating an
    autoreply.

52. Exim crashed if a remote delivery caused a very long error message to be
    recorded - for instance if somebody sent an entire SpamAssassin report back
    as a large number of 550 error lines. This bug was coincidentally fixed by
    increasing the size of one of Exim's internal buffers (big_buffer) that
    happened as part of the Exiscan merge. However, to be on the safe side, I
    have made the code more robust (and fixed the comments that describe what
    is going on).

53. Now that there can be additional text after "Completed" in log lines (if
    the queue_time_overall log selector is set), a one-byte patch to exigrep
    was needed to allow it to recognize "Completed" as not the last thing in
    the line.

54. The LDAP lookup was not handling a return of LDAP_RES_SEARCH_REFERENCE. A
    patch that reportedly fixes this has been added. I am not expert enough to
    create a test for it. This is what the patch creator wrote:

      "I found a little strange behaviour of ldap code when working with
      Windows 2003 AD Domain, where users was placed in more than one
      Organization Units. When I tried to give exim partial DN, the exit code
      of ldap_search was unknown to exim because of LDAP_RES_SEARCH_REFERENCE.
      But simultaneously result of request was absolutely normal ldap result,
      so I produce this patch..."

    Later: it seems that not all versions of LDAP support LDAP_RES_SEARCH_
    REFERENCE, so I have modified the code to exclude the patch when that macro
    is not defined.

55. Some experimental protocols are using DNS PTR records for new purposes. The
    keys for these records are domain names, not reversed IP addresses. The
    dnsdb PTR lookup now tests whether its key is an IP address. If not, it
    leaves it alone. Component reversal etc. now happens only for IP addresses.
    CAN-2005-0021

56. Improve error message when ldap_search() fails in OpenLDAP or Solaris LDAP.

57. Double the size of the debug message buffer (to 2048) so that more of very
    long debug lines gets shown.

58. The exicyclog utility now does better if the number of log files to keep
    exceeds 99. In this case, it numbers them 001, 002 ... instead of 01, 02...

59. Two changes related to the smtp_active_hostname option:

      (1) $smtp_active_hostname is now available as a variable.
      (2) The default for smtp_banner uses $smtp_active_hostname instead
          of $primary_hostname.

60. The host_aton() function is supposed to be passed a string that is known
    to be a valid IP address. However, in the case of IPv6 addresses, it was
    not checking this. This is a hostage to fortune. Exim now panics and dies
    if the condition is not met. A case was found where this could be provoked
    from a dnsdb PTR lookup with an IPv6 address that had more than 8
    components; fortuitously, this particular loophole had already been fixed
    by change 4.50/55 above.

    If there are any other similar loopholes, the new check in host_aton()
    itself should stop them being exploited. The report I received stated that
    data on the command line could provoke the exploit when Exim was running as
    exim, but did not say which command line option was involved. All I could
    find was the use of -be with a bad dnsdb PTR lookup, and in that case it is
    running as the user.
    CAN-2005-0021

61. There was a buffer overflow vulnerability in the SPA authentication code
    (which came originally from the Samba project). I have added a test to the
    spa_base64_to_bits() function which I hope fixes it.
    CAN-2005-0022

62. Configuration update for GNU/Hurd and variations. Updated Makefile-GNU and
    os.h-GNU, and added configuration files for GNUkFreeBSD and GNUkNetBSD.

63. The daemon start-up calls getloadavg() while still root for those OS that
    need the first call to be done as root, but it missed one case: when
    deliver_queue_load_max is set with deliver_drop_privilege. This is
    necessary for the benefit of the queue runner, because there is no re-exec
    when deliver_drop_privilege is set.

64. A call to exiwhat cut short delays set up by "delay" modifiers in ACLs.
    This has been fixed.

65. Caching of lookup data for "hosts =" ACL conditions, when a named host list
    was in use, was not putting the data itself into the right store pool;
    consequently, it could be overwritten for a subsequent message in the same
    SMTP connection. (Fix 4.40/11 dealt with the non-cache case, but overlooked
    the caching.)

66. Added hosts_max_try_hardlimit to the smtp transport, default 50.

67. The string_is_ip_address() function returns 0, 4, or 6, for "no an IP
    address", "IPv4 address", and "IPv6 address", respectively. Some calls of
    the function were treating the return as a boolean value, which happened to
    work because 0=false and not-0=true, but is not correct code.

68. The host_aton() function was not handling scoped IPv6 addresses (those
    with, for example, "%eth0" on the end) correctly.

69. Fixed some compiler warnings in acl.c for the bitmaps specified with
    negated items (that is, ~something) in unsigned ints. Some compilers
    apparently mutter when there is no cast.

70. If an address verification called from an ACL failed, and did not produce a
    user-specific message (i.e. there was only a "system" message), nothing was
    put in $acl_verify_message. In this situation, it now puts the system
    message there.

71. Change 4.23/11 added synchronization checking at the start of an SMTP
    session; change 4.31/43 added the unwanted input to the log line - except
    that it did not do this in the start of session case. It now does.

72. After a timeout in a callout SMTP session, Exim still sent a QUIT command.
    This is wrong and can cause the other end to generate a synchronization
    error if it is another Exim or anything else that does the synchronization
    check. A QUIT command is no longer sent after a timeout.

73. $host_lookup_deferred has been added, to make it easier to detect DEFERs
    during host lookups.

74. The defer_ok option of callout verification was not working if it was used
    when verifying addresses in header lines, that is, for this case:

      verify = header_sender/callout=defer_ok

75. A backgrounded daemon closed stdin/stdout/stderr on entry; this meant that
    those file descriptors could be used for SMTP connections. If anything
    wrote to stderr (the example that came up was "warn" in embedded Perl), it
    could be sent to the SMTP client, causing chaos. The daemon now opens
    stdin, stdout, and stderr to /dev/null when it puts itself into the
    background.

76. Arrange for output from Perl's "warn" command to be written to Exim's main
    log by default. The user can override this with suitable Perl magic.

77. The use of log_message on a "discard" ACL verb, which is supposed to add to
    the log message when discard triggers, was not working for the DATA ACL or
    for the non-SMTP ACL.

78. Error message wording change in sieve.c.

79. If smtp_accept_max_per_host was set, the number of connections could be
    restricted to fewer than expected, because the daemon was trying to set up
    a new connection before checking whether the processes handling previous
    connections had finished. The check for completed processes is now done
    earlier. On busy systems, this bug wouldn't be noticed because something
    else would have woken the daemon, and it would have reaped the completed
    process earlier.

80. If a message was submitted locally by a user whose login name contained one
    or more spaces (ugh!), the spool file that Exim wrote was not re-readable.
    It caused a spool format error. I have fixed the spool reading code. A
    related problem was that the "from" clause in the Received: line became
    illegal because of the space(s). It is now covered by ${quote_local_part.

81. Included the latest eximstats from Steve (adds average sizes to HTML Top
    tables).

82. Updated OS/Makefile-AIX as per message from Mike Meredith.

83. Patch from Sieve maintainer to fix unterminated string problem in
    "vacation" handling.

84. Some minor changes to the Linux configuration files to help with other
    OS variants using glibc.

85. One more patch for Sieve to update vacation handling to latest spec.


----------------------------------------------------
See the note above about the 4.44 and 4.50 releases.
----------------------------------------------------


Exim version 4.44
-----------------

 1. Change 4.43/35 introduced a bug that caused file counts to be
    incorrectly computed when quota_filecount was set in an appendfile
    transport

 2. Closing a stable door: arrange to panic-die if setitimer() ever fails. The
    bug fixed in 4.43/37 would have been diagnosed quickly if this had been in
    place.

 3. Give more explanation in the error message when the command for a transport
    filter fails to execute.

 4. There are several places where Exim runs a non-Exim command in a
    subprocess. The SIGUSR1 signal should be disabled for these processes. This
    was being done only for the command run by the queryprogram router. It is
    now done for all such subprocesses. The other cases are: ${run, transport
    filters, and the commands run by the lmtp and pipe transports.

 5. Some older OS have a limit of 256 on the maximum number of file
    descriptors. Exim was using setrlimit() to set 1000 as a large value
    unlikely to be exceeded. Change 4.43/17 caused a lot of logging on these
    systems. I've change it so that if it can't get 1000, it tries for 256.

 6. "control=submission" was allowed, but had no effect, in a DATA ACL. This
    was an oversight, and furthermore, ever since the addition of extra
    controls (e.g. 4.43/32), the checks on when to allow different forms of
    "control" were broken. There should now be diagnostics for all cases when a
    control that does not make sense is encountered.

 7. $recipients is now available in the predata ACL (oversight).

 8. Tidy the search cache before the fork to do a delivery from a message
    received from the command line. Otherwise the child will trigger a lookup
    failure and thereby defer the delivery if it tries to use (for example) a
    cached ldap connection that the parent has called unbind on.

 9. If verify=recipient was followed by verify=sender in a RCPT ACL, the value
    of $address_data from the recipient verification was clobbered by the
    sender verification.

10. If FIXED_NEVER_USERS was defined, but empty, Exim was assuming the uid 0
    was its contents. (It was OK if the option was not defined at all.)

11. A "Completed" log line is now written for messages that are removed from
    the spool by the -Mrm option.

12. $host_address is now set to the target address during the checking of
    ignore_target_hosts.

13. When checking ignore_target_hosts for an ipliteral router, no host name was
    being passed; this would have caused $sender_host_name to have been used if
    matching the list had actually called for a host name (not very likely,
    since this list is usually IP addresses). A host name is now passed as
    "[x.x.x.x]".

14. Changed the calls that set up the SIGCHLD handler in the daemon to use the
    code that specifies a non-restarting handler (typically sigaction() in
    modern systems) in an attempt to fix a rare and obscure crash bug.

15. Narrowed the window for a race in the daemon that could cause it to ignore
    SIGCHLD signals. This is not a major problem, because they are used only to
    wake it up if nothing else does.

16. A malformed maildirsize file could cause Exim to calculate negative values
    for the mailbox size or file count. Odd effects could occur as a result.
    The maildirsize information is now recalculated if the size or filecount
    end up negative.

17. Added HAVE_SYS_STATVFS_H to the os.h file for Linux, as it has had this
    support for a long time. Removed HAVE_SYS_VFS_H.

18. Updated exipick to current release from John Jetmore.

19. Allow an empty sender to be matched against a lookup in an address list.
    Previously the only cases considered were a regular expression, or an
    empty pattern.

20. Exim went into a mad DNS lookup loop when doing a callout where the
    host was specified on the transport, if the DNS lookup yielded more than
    one IP address.

21. The RFC2047 encoding function was originally intended for short strings
    such as real names; it was not keeping to the 75-character limit for
    encoded words that the RFC imposes. It now respects the limit, and
    generates multiple encoded words if necessary. To be on the safe side, I
    have increased the buffer size for the ${rfc2047: expansion operator from
    1024 to 2048 bytes.

22. Failure to deliver a bounce message always caused it to be frozen, even if
    there was an errors_to setting on the router. The errors_to setting is now
    respected.

23. If an IPv6 address is given for -bh or -bhc, it is now converted to the
    canonical form (fully expanded) before being placed in
    $sender_host_address.

24. Updated eximstats to version 1.33

25. Include certificate and key file names in error message when GnuTLS fails
    to set them up, because the GnuTLS error message doesn't include the name
    of the failing file when there is a problem reading it.

26. Expand error message when OpenSSL has problems setting up cert/key files.
    As per change 25.

27. Reset the locale to "C" after calling embedded Perl, in case it was changed
    (this can affect the format of dates).

28. exim_tidydb, when checking for the continued existence of a message for
    which it has found a message-specific retry record, was not finding
    messages that were in split spool directories. Consequently, it was
    deleting retry records that should have stayed in existence.

29. eximstats updated to version 1.35
    1.34 - allow eximstats to parse syslog lines as well as mainlog lines
    1.35 - bugfix such that pie charts by volume are generated correctly

30. The SPA authentication driver was not abandoning authentication and moving
    on to the next authenticator when an expansion was forced to fail,
    contradicting the general specification for all authenticators. Instead it
    was generating a temporary error. It now behaves as specified.

31. The default ordering of permitted cipher suites for GnuTLS was pessimal
    (the order specifies the preference for clients). The order is now AES256,
    AES128, 3DES, ARCFOUR128.

31. Small patch to Sieve code - explicitly set From: when generating an
    autoreply.

32. Exim crashed if a remote delivery caused a very long error message to be
    recorded - for instance if somebody sent an entire SpamAssassin report back
    as a large number of 550 error lines. This bug was coincidentally fixed by
    increasing the size of one of Exim's internal buffers (big_buffer) that
    happened as part of the Exiscan merge. However, to be on the safe side, I
    have made the code more robust (and fixed the comments that describe what
    is going on).

33. Some experimental protocols are using DNS PTR records for new purposes. The
    keys for these records are domain names, not reversed IP addresses. The
    dnsdb PTR lookup now tests whether its key is an IP address. If not, it
    leaves it alone. Component reversal etc. now happens only for IP addresses.
    CAN-2005-0021

34. The host_aton() function is supposed to be passed a string that is known
    to be a valid IP address. However, in the case of IPv6 addresses, it was
    not checking this. This is a hostage to fortune. Exim now panics and dies
    if the condition is not met. A case was found where this could be provoked
    from a dnsdb PTR lookup with an IPv6 address that had more than 8
    components; fortuitously, this particular loophole had already been fixed
    by change 4.50/55 or 4.44/33 above.

    If there are any other similar loopholes, the new check in host_aton()
    itself should stop them being exploited. The report I received stated that
    data on the command line could provoke the exploit when Exim was running as
    exim, but did not say which command line option was involved. All I could
    find was the use of -be with a bad dnsdb PTR lookup, and in that case it is
    running as the user.
    CAN-2005-0021

35. There was a buffer overflow vulnerability in the SPA authentication code
    (which came originally from the Samba project). I have added a test to the
    spa_base64_to_bits() function which I hope fixes it.
    CAN-2005-0022

36. The daemon start-up calls getloadavg() while still root for those OS that
    need the first call to be done as root, but it missed one case: when
    deliver_queue_load_max is set with deliver_drop_privilege. This is
    necessary for the benefit of the queue runner, because there is no re-exec
    when deliver_drop_privilege is set.

37. Caching of lookup data for "hosts =" ACL conditions, when a named host list
    was in use, was not putting the data itself into the right store pool;
    consequently, it could be overwritten for a subsequent message in the same
    SMTP connection. (Fix 4.40/11 dealt with the non-cache case, but overlooked
    the caching.)

38. Sometimes the final signoff response after QUIT could fail to get
    transmitted in the non-TLS case. Testing !tls_active instead of tls_active
    < 0 before doing a fflush(). This bug looks as though it goes back to the
    introduction of TLS in release 3.20, but "sometimes" must have been rare
    because the tests only now provoked it.


Exim version 4.43
-----------------

 1. Fixed a longstanding but relatively impotent bug: a long time ago, before
    PIPELINING, the function smtp_write_command() used to return TRUE or FALSE.
    Now it returns an integer. A number of calls were still expecting a T/F
    return. Fortuitously, in all cases, the tests worked in OK situations,
    which is the norm. However, things would have gone wrong on any write
    failures on the smtp file descriptor. This function is used when sending
    messages over SMTP and also when doing verify callouts.

 2. When Exim is called to do synchronous delivery of a locally submitted
    message (the -odf or -odi options), it no longer closes stderr before doing
    the delivery.

 3. Implemented the mua_wrapper option.

 4. Implemented mx_fail_domains and srv_fail_domains for the dnslookup router.

 5. Implemented the functions header_remove(), header_testname(),
    header_add_at_position(), and receive_remove_recipient(), and exported them
    to local_scan().

 6. If an ACL "warn" statement specified the addition of headers, Exim already
    inserted X-ACL-Warn: at the start if there was no header name. However, it
    was not making this test for the second and subsequent header lines if
    there were newlines in the string. This meant that an invalid header could
    be inserted if Exim was badly configured.

 7. Allow an ACL "warn" statement to add header lines at the start or after all
    the Received: headers, as well as at the end.

 8. Added the rcpt_4xx retry error code.

 9. Added postmaster_mailfrom=xxx to callout verification option.

10. Added mailfrom=xxxx to the callout verification option, for verify=
    header_sender only.

11. ${substr_1_:xxxx} and ${substr__3:xxxx} are now diagnosed as syntax errors
    (they previously behaved as ${substr_1_0:xxxx} and ${substr:_0_3:xxxx}).

12. Inserted some casts to stop certain compilers warning when using pointer
    differences as field lengths or precisions in printf-type calls (mostly
    affecting debugging statements).

13. Added optional readline() support for -be (dynamically loaded).

14. Obscure bug fix: if a message error (e.g. 4xx to MAIL) happened within the
    same clock tick as a message's arrival, so that its received time was the
    same as the "first fail" time on the retry record, and that message
    remained on the queue past the ultimate address timeout, every queue runner
    would try a delivery (because it was past the ultimate address timeout) but
    after another failure, the ultimate address timeout, which should have then
    bounced the address, did not kick in. This was a "< instead of <=" error;
    in most cases the first failure would have been in the next clock tick
    after the received time, and all would be well.

15. The special items beginning with @ in domain lists (e.g. @mx_any) were not
    being recognized when the domain list was tested by the match_domain
    condition in an expansion string.

16. Added the ${str2b64: operator.

17. Exim was always calling setrlimit() to set a large limit for the number of
    processes, without checking whether the existing limit was already
    adequate. (It did check for the limit on file descriptors.) Furthermore,
    errors from getrlimit() and setrlimit() were being ignored. Now they are
    logged to the main and panic logs, but Exim does carry on, to try to do its
    job under whatever limits there are.

18. Imported PCRE 5.0.

19. Trivial typo in log message " temporarily refused connection" (the leading
    space).

20. If the log selector return_path_on_delivery was set and an address was
    redirected to /dev/null, the delivery process crashed because it assumed
    that a return path would always be set for a "successful" delivery. In this
    case, the whole delivery is bypassed as an optimization, and therefore no
    return path is set.

21. Internal re-arrangement: the function for sending a challenge and reading
    a response while authentication was assuming a zero-terminated challenge
    string. It's now changed to take a pointer and a length, to allow for
    binary data in such strings.

22. Added the cyrus_sasl authenticator (code supplied by MBM).

23. Exim was not respecting finduser_retries when seeking the login of the
    uid under which it was called; it was always trying 10 times. (The default
    setting of finduser_retries is zero.) Also, it was sleeping after the final
    failure, which is pointless.

24. Implemented tls_on_connect_ports.

25. Implemented acl_smtp_predata.

26. If the domain in control=submission is set empty, Exim assumes that the
    authenticated id is a complete email address when it generates From: or
    Sender: header lines.

27. Added "#define SOCKLEN_T int" to OS/os.h-SCO and OS/os.h-SCO_SV. Also added
    definitions to OS/Makefile-SCO and OS/Makefile-SCO_SV that put basename,
    chown and chgrp in /bin and hostname in /usr/bin.

28. Exim was keeping the "process log" file open after each use, just as it
    does for the main log. This opens the possibility of it remaining open for
    long periods when the USR1 signal hits a daemon. Occasional processlog
    errors were reported, that could have been caused by this. Anyway, it seems
    much more sensible not to leave this file open at all, so that is what now
    happens.

29. The long-running daemon process does not normally write to the log once it
    has entered its main loop, and it closes the log before doing so. This is
    so that log files can straightforwardly be renamed and moved. However,
    there are a couple of unusual error situations where the daemon does write
    log entries, and I had neglected to close the log afterwards.

30. The text of an SMTP error response that was received during a remote
    delivery was being truncated at 512 bytes. This is too short for some of
    the long messages that one sometimes sees. I've increased the limit to
    1024.

31. It is now possible to make retry rules that apply only when a message has a
    specific sender, in particular, an empty sender.

32. Added "control = enforce_sync" and "control = no_enforce_sync". This makes
    it possible to be selective about when SMTP synchronization is enforced.

33. Added "control = caseful_local_part" and "control = "caselower_local_part".

32. Implemented hosts_connection_nolog.

33. Added an ACL for QUIT.

34. Setting "delay_warning=" to disable warnings was not working; it gave a
    syntax error.

35. Added mailbox_size and mailbox_filecount to appendfile.

36. Added control = no_multiline_responses to ACLs.

37. There was a bug in the logic of the code that waits for the clock to tick
    in the case where the clock went backwards by a substantial amount such
    that the microsecond fraction of "now" was more than the microsecond
    fraction of "then" (but the whole seconds number was less).

38. Added support for the libradius Radius client library this is found on
    FreeBSD (previously only the radiusclient library was supported).


Exim version 4.42
-----------------

 1. When certain lookups returned multiple values in the form name=value, the
    quoting of the values was not always being done properly. Specifically:
    (a) If the value started with a double quote, but contained no whitespace,
        it was not quoted.
    (b) If the value contained whitespace other than a space character (i.e.
        tabs or newlines or carriage returns) it was not quoted.
    This fix has been applied to the mysql and pgsql lookups by writing a
    separate quoting function and calling it from the lookup code. The fix
    should probably also be applied to nisplus, ibase and oracle lookups, but
    since I cannot test any of those, I have not disturbed their existing code.

 2. A hit in the callout cache for a specific address caused a log line with no
    reason for rejecting RCPT. Now it says "Previous (cached) callout
    verification failure".

 3. There was an off-by-one bug in the queryprogram router. An over-long
    return line was truncated at 256 instead of 255 characters, thereby
    overflowing its buffer with the terminating zero. As well as fixing this, I
    have increased the buffer size to 1024 (and made a note to document this).

 4. If an interrupt, such as the USR1 signal that is send by exiwhat, arrives
    when Exim is waiting for an SMTP response from a remote server, Exim
    restarts its select() call on the socket, thereby resetting its timeout.
    This is not a problem when such interrupts are rare. Somebody set up a cron
    job to run exiwhat every 2 minutes, which is less than the normal select()
    timeout (5 or 10 minutes). This meant that the select() timeout never
    kicked in because it was always reset. I have fixed this by comparing the
    time when an interrupt arrives with the time at the start of the first call
    to select(). If more time than the timeout has elapsed, the interrupt is
    treated as a timeout.

 5. Some internal re-factoring in preparation for the addition of Sieve
    extensions (by MH). In particular, the "personal" test is moved to a
    separate function, and given an option for scanning Cc: and Bcc: (which is
    not set for Exim filters).

 6. When Exim created an email address using the login of the caller as the
    local part (e.g. when creating a From: or Sender: header line), it was not
    quoting the local part when it contained special characters such as @.

 7. Installed new OpenBSD configuration files.

 8. Reworded some messages for syntax errors in "and" and "or" conditions to
    try to make them clearer.

 9. Callout options, other than the timeout value, were being ignored when
    verifying sender addresses in header lines. For example, when using

      verify = header_sender/callout=no_cache

    the cache was (incorrectly) being used.

10. Added a missing instance of ${EXE} to the exim_install script; this affects
    only the Cygwin environment.

11. When return_path_on_delivery was set as a log selector, if different remote
    addresses in the same message used different return paths and parallel
    remote delivery occurred, the wrong values would sometimes be logged.
    (Whenever a remote delivery process finished, the return path value from
    the most recently started remote delivery process was logged.)

12. RFC 3848 specifies standard names for the "with" phrase in Received: header
    lines when AUTH and/or TLS are in use. This is the "received protocol"
    field. Exim used to use "asmtp" for authenticated SMTP, without any
    indication (in the protocol name) for TLS use. Now it follows the RFC and
    uses "esmtpa" if the connection is authenticated, "esmtps" if it is
    encrypted, and "esmtpsa" if it is both encrypted and authenticated. These
    names appear in log lines as well as in Received: header lines.

13. Installed MH's patches for Sieve to add the "copy" and "vacation"
    extensions, and comparison tests, and to fix some bugs.

14. Changes to the "personal" filter test:

    (1) The test was buggy in that it was just doing the equivalent of
    "contains" tests on header lines. For example, if a user's address was
    anne@some.where, the "personal" test would incorrectly be true for

      To: susanne@some.where

    This test is now done by extracting each address from the header in turn,
    and checking the entire address. Other tests that are part of "personal"
    are now done using regular expressions (for example, to check local parts
    of addresses in From: header lines).

    (2) The list of non-personal local parts in From: addresses has been
    extended to include "listserv", "majordomo", "*-request", and "owner-*",
    taken from the Sieve specification recommendations.

    (3) If the message contains any header line starting with "List-" it is
    treated as non-personal.

    (4) The test for "circular" in the Subject: header line has been removed
    because it now seems ill-conceived.

15. Minor typos in src/EDITME comments corrected.

16. Installed latest exipick from John Jetmore.

17. If headers_add on a router specified a text string that was too long for
    string_sprintf() - that is, longer than 8192 bytes - Exim panicked. The use
    of string_sprintf() is now avoided.

18. $message_body_size was not set (it was always zero) when running the DATA
    ACL and the local_scan() function.

19. For the "mail" command in an Exim filter, no default was being set for
    the once_repeat time, causing a random time value to be used if "once" was
    specified. (If the value happened to be <= 0, no repeat happened.) The
    default is now 0s, meaning "never repeat". The "vacation" command was OK
    (its default is 7d). It's somewhat surprising nobody ever noticed this bug
    (I found it when inspecting the code).

20. There is now an overall timeout for performing a callout verification. It
    defaults to 4 times the callout timeout, which applies to individual SMTP
    commands during the callout. The overall timeout applies when there is more
    than one host that can be tried. The timeout is checked before trying the
    next host. This prevents very long delays if there are a large number of
    hosts and all are timing out (e.g. when the network connections are timing
    out). The value of the overall timeout can be changed by specifying an
    additional sub-option for "callout", called "maxwait". For example:

      verify = sender/callout=5s,maxwait=20s

21. Add O_APPEND to the open() call for maildirsize files (Exim already seeks
    to the end before writing, but this should make it even safer).

22. Exim was forgetting that it had advertised PIPELINING for the second and
    subsequent messages on an SMTP connection. It was also not resetting its
    memory on STARTTLS and an internal HELO.

23. When Exim logs an SMTP synchronization error within a session, it now
    records whether PIPELINING has been advertised or not.

24. Added 3 instances of "(long int)" casts to time_t variables that were being
    formatted using %ld, because on OpenBSD (and perhaps others), time_t is int
    rather than long int.

25. Installed the latest Cygwin configuration files from the Cygwin maintainer.

26. Added the never_mail option to autoreply.


Exim version 4.41
-----------------

 1. A reorganization of the code in order to implement 4.40/8 caused a daemon
    crash if the getsockname() call failed; this can happen if a connection is
    closed very soon after it is established. The problem was simply in the
    order in which certain operations were done, causing Exim to try to write
    to the SMTP stream before it had set up the file descriptor. The bug has
    been fixed by making things happen in the correct order.


Exim version 4.40
-----------------

 1. If "drop" was used in a DATA ACL, the SMTP output buffer was not flushed
    before the connection was closed, thus losing the rejection response.

 2. Commented out the definition of SOCKLEN_T in os.h-SunOS5. It is needed for
    some early Solaris releases, but causes trouble in current releases where
    socklen_t is defined.

 3. When std{in,out,err} are closed, re-open them to /dev/null so that they
    always exist.

 4. Minor refactoring of os.c-Linux to avoid compiler warning when IPv6 is not
    configured.

 5. Refactoring in expand.c to improve memory usage. Pre-allocate a block so
    that releasing the top of it at the end releases what was used for sub-
    expansions (unless the block got too big). However, discard this block if
    the first thing is a variable or header, so that we can use its block when
    it is dynamic (useful for very large $message_headers, for example).

 6. Lookups now cache *every* query, not just the most recent. A new, separate
    store pool is used for this. It can be recovered when all lookup caches are
    flushed. Lookups now release memory at the end of their result strings.
    This has involved some general refactoring of the lookup sources.

 7. Some code has been added to the store_xxx() functions to reduce the amount
    of flapping under certain conditions.

 8. log_incoming_interface used to affect only the <= reception log lines. Now
    it causes the local interface and port to be added to several more SMTP log
    lines, for example "SMTP connection from", and rejection lines.

 9. The Sieve author supplied some patches for the doc/README.SIEVE file.

10. Added a conditional definition of _BSD_SOCKLEN_T to os.h-Darwin.

11. If $host_data was set by virtue of a hosts lookup in an ACL, its value
    could be overwritten at the end of the current message (or the start of a
    new message if it was set in a HELO ACL). The value is now preserved for
    the duration of the SMTP connection.

12. If a transport had a headers_rewrite setting, and a matching header line
    contained an unqualified address, that address was qualified, even if it
    did not match any rewriting rules. The underlying bug was that the values
    of the flags that permit the existence of unqualified sender and recipient
    addresses in header lines (set by {sender,recipient}_unqualified_hosts for
    non-local messages, and by -bnq for local messages) were not being
    preserved with the message after it was received.

13. When Exim was logging an SMTP synchronization error, it could sometimes log
    "next input=" as part of the text comprising the host identity instead of
    the correct text. The code was using the same buffer for two different
    strings. However, depending on which order the printing function evaluated
    its arguments, the bug did not always show up. Under Linux, for example, my
    test suite worked just fine.

14. Exigrep contained a use of Perl's "our" scoping after change 4.31/70. This
    doesn't work with some older versions of Perl. It has been changed to "my",
    which in any case is probably the better facility to use.

15. A really picky compiler found some instances of statements for creating
    error messages that either had too many or two few arguments for the format
    string.

16. The size of the buffer for calls to the DNS resolver has been increased
    from 1024 to 2048. A larger buffer is needed when performing PTR lookups
    for addresses that have a lot of PTR records. This alleviates a problem; it
    does not fully solve it.

17. A dnsdb lookup for PTR records that receives more data than will fit in the
    buffer now truncates the list and logs the incident, which is the same
    action as happens when Exim is looking up a host name and its aliases.
    Previously in this situation something unpredictable would happen;
    sometimes it was "internal error: store_reset failed".

18. If a server dropped the connection unexpectedly when an Exim client was
    using GnuTLS and trying to read a response, the client delivery process
    crashed while trying to generate an error log message.

19. If a "warn" verb in an ACL added multiple headers to a message in a single
    string, for example:

      warn message = H1: something\nH2: something

    the text was added as a single header line from Exim's point of view
    though it ended up OK in the delivered message. However, searching for the
    second and subsequent header lines using $h_h2: did not work. This has been
    fixed. Similarly, if a system filter added multiple headers in this way,
    the routers could not see them.

20. Expanded the error message when iplsearch is called with an invalid key to
    suggest using net-iplsearch in a host list.

21. When running tests using -bh, any delays imposed by "delay" modifiers in
    ACLs are no longer actually imposed (and a message to that effect is
    output).

22. If a "gecos" field in a passwd entry contained escaped characters, in
    particular, if it contained a \" sequence, Exim got it wrong when building
    a From: or a Sender: header from that name. A second bug also caused
    incorrect handling when an unquoted " was present following a character
    that needed quoting.

23. "{crypt}" as a password encryption mechanism for a "crypteq" expansion item
    was not being matched caselessly.

24. Arranged for all hyphens in the exim.8 source to be escaped with
    backslashes.

25. Change 16 of 4.32, which reversed 71 or 4.31 didn't quite do the job
    properly. Recipient callout cache records were still being keyed to include
    the sender, even when use_sender was set false. This led to far more
    callouts that were necessary. The sender is no longer included in the key
    when use_sender is false.

26. Added "control = submission" modifier to ACLs.

27. Added the ${base62d: operator to decode base 62 numbers.

28. dnsdb lookups can now access SRV records.

29. CONFIGURE_OWNER can be set at build time to define an alternative owner for
    the configuration file.

30. The debug message "delivering xxxxxx-xxxxxx-xx" is now output in verbose
    (-v) mode. This makes the output for a verbose queue run more intelligible.

31. Added a use_postmaster feature to recipient callouts.

32. Added the $body_zerocount variable, containing the number of binary zero
    bytes in the message body.

33. The time of last modification of the "new" subdirectory is now used as the
    "mailbox time last read" when there is a quota error for a maildir
    delivery.

34. Added string comparison operators lt, lti, le, lei, gt, gti, ge, gei.

35. Added +ignore_unknown as a special item in host lists.

36. Code for decoding IPv6 addresses in host lists is now included, even if
    IPv6 support is not being compiled. This fixes a bug in which an IPv6
    address was recognized as an IP address, but was then not correctly decoded
    into binary, causing unexpected and incorrect effects when compared with
    another IP address.


Exim version 4.34
-----------------

 1. Very minor rewording of debugging text in manualroute to say "list of
    hosts" instead of "hostlist".

 2. If verify=header_syntax was set, and a header line with an unqualified
    address (no domain) and a large number of spaces between the end of the
    name and the colon was received, the reception process suffered a buffer
    overflow, and (when I tested it) crashed. This was caused by some obsolete
    code that should have been removed. The fix is to remove it!

 3. When running in the test harness, delay a bit after writing a bounce
    message to get a bit more predictability in the log output.

 4. Added a call to search_tidyup() just before forking a reception process. In
    theory, someone could use a lookup in the expansion of smtp_accept_max_
    per_host which, without the tidyup, could leave open a database connection.

 5. Added the variables $recipient_data and $sender_data which get set from a
    lookup success in an ACL "recipients" or "senders" condition, or a router
    "senders" option, similar to $domain_data and $local_part_data.

 6. Moved the writing of debug_print from before to after the "senders" test
    for routers.

 7. Change 4.31/66 (moving the time when the Received: is generated) caused
    problems for message scanning, either using a data ACL, or using
    local_scan() because the Received: header was not generated till after they
    were called (in order to set the time as the time of reception completion).
    I have revised the way this works. The header is now generated after the
    body is received, but before the ACL or local_scan() are called. After they
    are run, the timestamp in the header is updated.


Exim version 4.33
-----------------

 1. Change 4.24/6 introduced a bug because the SIGALRM handler was disabled
    before starting a queue runner without re-exec. This happened only when
    deliver_drop_privilege was set or when the Exim user was set to root. The
    effect of the bug was that timeouts during subsequent deliveries caused
    crashes instead of being properly handled. The handler is now left at its
    default (and expected) setting.

 2. The other case in which a daemon avoids a re-exec is to deliver an incoming
    message, again when deliver_drop_privilege is set or Exim is run as root.
    The bug described in (1) was not present in this case, but the tidying up
    of the other signals was missing. I have made the two cases consistent.

 3. The ignore_target_hosts setting on a manualroute router was being ignored
    for hosts that were looked up using the /MX notation.

 4. Added /ignore=<ip list> feature to @mx_any, @mx_primary, and @mx_secondary
    in domain lists.

 5. Change 4.31/55 was buggy, and broke when there was a rewriting rule that
    operated on the sender address. After changing the $sender_address to <>
    for the sender address verify, Exim was re-instated it as the original
    (before rewriting) address, but remembering that it had rewritten it, so it
    wasn't rewriting it again. This bug also had the effect of breaking the
    sender address verification caching when the sender address was rewritten.

 6. The ignore_target_hosts option was being ignored by the ipliteral router.
    This has been changed so that if the ip literal address matches
    ignore_target_hosts, the router declines.

 7. Added expansion conditions match_domain, match_address, and match_local_
    part (NOT match_host).

 8. The placeholder for the Received: header didn't have a length field set.

 9. Added code to Exim itself and to exim_lock to test for a specific race
    condition that could lead to file corruption when using MBX delivery. The
    issue is with the lockfile that is created in /tmp. If this file is removed
    after a process has opened it but before that process has acquired a lock,
    there is the potential for a second process to recreate the file and also
    acquire a lock. This could lead to two Exim processes writing to the file
    at the same time. The added code performs the same test as UW imapd; it
    checks after acquiring the lock that its file descriptor still refers to
    the same named file.

10. The buffer for building added header lines was of fixed size, 8192 bytes.
    It is now parameterized by HEADER_ADD_BUFFER_SIZE and this can be adjusted
    when Exim is built.

11. Added the smtp_active_hostname option. If used, this will typically be made
    to depend on the incoming interface address. Because $interface_address is
    not set up until the daemon has forked a reception process, error responses
    that can happen earlier (such as "too many connections") no longer contain
    a host name.

12. If an expansion in a condition on a "warn" statement fails because a lookup
    defers, the "warn" statement is abandoned, and the next ACL statement is
    processed. Previously this caused the whole ACL to be aborted.

13. Added the iplsearch lookup type.

14. Added ident_timeout as a log selector.

15. Added tls_certificate_verified as a log selector.

16. Added a global option tls_require_ciphers (compare the smtp transport
    option of the same name). This controls incoming TLS connections.

17. I finally figured out how to make tls_require_ciphers do a similar thing
    in GNUtls to what it does in OpenSSL, that is, set up an appropriate list
    before starting the TLS session.

18. Tabs are now shown as \t in -bP output.

19. If the log selector return_path_on_delivery was set, Exim crashed when
    bouncing a message because it had too many Received: header lines.

20. If two routers both had headers_remove settings, and the first one included
    a superfluous trailing colon, the final name in the first list and the
    first name in the second list were incorrectly joined into one item (with a
    colon in the middle).


Exim version 4.32
-----------------

 1. Added -C and -D options to the exinext utility, mainly to make it easier
    to include in the automated testing, but these could be helpful when
    multiple configurations are in use.

 2. The exinext utility was not formatting the output nicely when there was
    an alternate port involved in the retry record key, nor when there was a
    message id as well (for retries that were specific to a specific message
    and a specific host). It was also confused by IPv6 addresses, because of
    the additional colons they contain. I have fixed the IPv4 problem, and
    patched it up to do a reasonable job for IPv6.

 3. When there is an error after a MAIL, RCPT, or DATA SMTP command during
    delivery, the log line now contains "pipelined" if PIPELINING was used.

 4. An SMTP transport process used to panic and die if the bind() call to set
    an explicit outgoing interface failed. This has been changed; it is now
    treated in the same way as a connect() failure.

 5. A reference to $sender_host_name in the part of a conditional expansion
    that was being skipped was still causing a DNS lookup. This no longer
    occurs.

 6. The def: expansion condition was not recognizing references to header lines
    that used bh_ and bheader_.

 7. Added the _cache feature to named lists.

 8. The code for checking quota_filecount in the appendfile transport was
    allowing one more file than it should have been.

 9. For compatibility with Sendmail, the command line option

      -prval:sval

    is equivalent to

      -oMr rval -oMs sval

    and sets the incoming protocol and host name (for trusted callers). The
    host name and its colon can be omitted when only the protocol is to be set.
    Note the Exim already has two private options, -pd and -ps, that refer to
    embedded Perl. It is therefore impossible to set a protocol value of "d" or
    "s", but I don't think that's a major issue.

10. A number of refactoring changes to the code, none of which should affect
    Exim's behaviour:

    (a) The number of logging options was getting close to filling up the
    32-bit word that was used as a bit map. I have split them into two classes:
    those that are passed in the argument to log_write(), and those that are
    only ever tested independently outside of that function. These are now in
    separate 32-bit words, so there is plenty of room for expansion again.
    There is no change in the user interface or the logging behaviour.

    (b) When building, for example, log lines, the code previously used a
    macro that called string_cat() twice, in order to add two strings. This is
    not really sufficiently general. Furthermore, there was one instance where
    it was actually wrong because one of the argument was used twice, and in
    one call a function was used. (As it happened, calling the function twice
    did not affect the overall behaviour.) The macro has been replaced by a
    function that can join an arbitrary number of extra strings onto a growing
    string.

    (c) The code for expansion conditions now uses a table and a binary chop
    instead of a serial search (which was left over from when there were very
    few conditions). Also, it now recognizes conditions like "pam" even when
    the relevant support is not compiled in: a suitably worded error message is
    given if an attempt is made to use such a condition.

11. Added ${time_interval:xxxxx}.

12. A bug was causing one of the ddress fields not to be passed back correctly
    from remote delivery subprocesses. The field in question was not being
    subsequently used, so this caused to problems in practice.

13. Added new log selectors queue_time and deliver_time.

14. Might have fixed a bug in maildirsizefile handling that threw up
    "unexpected character" debug warnings, and recalculated the data
    unnecessarily. In any case, I expanded the warning message to give more
    information.

15. Added the message "Restricted characters in address" to the statements in
    the default ACL that block characters like @ and % in local parts.

16. Change 71 for release 4.31 proved to be much less benign that I imagined.
    Three changes have been made:

    (a) There was a serious bug; a negative response to MAIL caused the whole
        recipient domain to be cached as invalid, thereby blocking all messages
        to all local parts at the same domain, from all senders. This bug has
        been fixed. The domain is no longer cached after a negative response to
        MAIL if the sender used is not empty.

    (b) The default behaviour of using MAIL FROM:<> for recipient callouts has
        been restored.

    (c) A new callout option, "use_sender" has been added for people who want
        the modified behaviour.


Exim version 4.31
-----------------

 1. Removed "EXTRALIBS=-lwrap" from OS/Makefile-Unixware7 on the advice of
    Larry Rosenman.

 2. Removed "LIBS = -lresolv" from OS/Makefile-Darwin as it is not needed, and
    indeed breaks things for older releases.

 3. Added additional logging to the case where there is a problem reading data
    from a filter that is running in a subprocess using a pipe, in order to
    try to track down a specific problem.

 4. Testing facility fudge: when running in the test harness and attempting
    to connect to 10.x.x.x (expecting a connection timeout) I'm now sometimes
    getting "No route to host". Convert this to a timeout.

 5. Define ICONV_ARG2_TYPE as "char **" for Unixware7 to avoid compiler
    warning.

 6. Some OS don't have socklen_t but use size_t instead. This affects the
    fifth argument of getsockopt() amongst other things. This is now
    configurable by a macro called SOCKLEN_T which defaults to socklen_t, but
    can be set for individual OS. I have set it for SunOS5, OSF1, and
    Unixware7. Current versions of SunOS5 (aka Solaris) do have socklen_t, but
    some earlier ones do not.

 7. Change 4.30/15 was not doing the test caselessly.

 8. The standard form for an IPv6 address literal was being rejected by address
    parsing in, for example, MAIL and RCPT commands. An example of this kind of
    address is [IPv6:2002:c1ed:8229:10:202:2dff:fe07:a42a]. Exim now accepts
    this, as well as the form without the "IPv6" on the front (but only when
    address literals are enabled, of course).

 9. Added some casts to avoid compiler warnings in OS/os.c-Linux.

10. Exim crashed if a message with an empty sender address specified by -f
    encountered a router with an errors_to setting. This could be provoked only
    by a command such as

      exim -f "" ...

    where an empty string was supplied; "<>" did not hit this bug.

11. Installed PCRE release 4.5.

12. If EHLO/HELO was rejected by an ACL, the value of $sender_helo_name
    remained set. It is now erased.

13. exiqgrep wasn't working on MacOS X because it didn't correctly compute
    times from message ids (which are base 36 rather than the normal 62).

14. "Expected" SMTP protocol errors that can arise when PIPELINING is in use
    were being counted as actual protocol errors, and logged if the log
    selector +smtp_protocol_error was set. One cannot be perfect in this test,
    but now, if PIPELINING has been advertised, RCPT following a rejected MAIL,
    and DATA following a set of rejected RCPTs do not count as protocol errors.
    In other words, Exim assumes they were pipelined, though this may not
    actually be the case. Of course, in all cases the client gets an
    appropriate error code.

15. If a lookup fails in an ACL condition, a message about the failure may
    be available; it is used if testing the ACL cannot continue, because most
    such messages specify what the cause of the deferral is. However, some
    messages (e.g. "MYSQL: no data found") do not cause a defer. There was bug
    that caused an old message to be retained and used if a later statement
    caused a defer, replacing the real cause of the deferral.

16. If an IP address had so many PTR records that the DNS lookup buffer
    was not large enough to hold them, Exim could crash while trying to process
    the truncated data. It now detects and logs this case.

17. Further to 4.21/58, another change has been made: if (and only if) the
    first line of a message (the first header line) ends with CRLF, a bare LF
    in a subsequent header line has a space inserted after it, so as not to
    terminate the header.

18. Refactoring: tidied an ugly bit of code in appendfile that copied data
    unnecessarily, used atoi() instead of strtol(), and didn't check the
    termination when getting file sizes from file names by regex.

19. Completely re-implemented the support for maildirsize files, in the light
    of a number of problems with the previous contributed implementation
    (4.30/29). In particular:

    . If the quota is zero, the maildirsize file is maintained, but no quota is
      imposed.

    . If the maildir directory does not exist, it is created before any attempt
      to write a maildirsize file.

    . The quota value in the file is just a cache; if the quota is changed in
      the transport, the new value overrides.

    . A regular expression is available for excluding directories from the
      count.

20. The autoreply transport checks the characters in options that define the
    message's headers; it allows continued headers, but it was checking with
    isspace() after an embedded newline instead of explicitly looking for a
    space or a tab.

21. If all the "regular" hosts to which an address was routed had passed their
    expiry times, and had not reached their retry times, the address was
    bounced, even if fallback hosts were defined. Now Exim should go on to try
    the fallback hosts.

22. Increased buffer sizes in the callout code from 1024 to 4096 to match the
    equivalent code in the SMTP transport. Some hosts send humungous responses
    to HELO/EHLO, more than 1024 it seems.

23. Refactoring: code in filter.c used (void *) for "any old type" but this
    gives compiler warnings in some environments. I've now done it "properly",
    using a union.

24. The replacement for inet_ntoa() that is used with gcc on IRIX systems
    (because of problems with the built-in one) was declared to return uschar *
    instead of char *, causing compiler failure.

25. Fixed a file descriptor leak when processing alias/forward files.

26. Fixed a minor format string issue in dbfn.c.

27. Typo in exim.c: ("dmbnz" for "dbmnz").

28. If a filter file refered to $h_xxx or $message_headers, and the headers
    contained RFC 2047 "words", Exim's memory could, under certain conditions,
    become corrupted.

29. When a sender address is verified, it is cached, to save repeating the test
    when there is more than one recipient in a message. However, when the
    verification involves a callout, it is possible for different callout
    options to be set for different recipients. It is too complicated to keep
    track of this in the cache, so now Exim always runs a verification when a
    callout is required, relying on the callout cache for the optimization.
    The overhead is duplication of the address routing, but this should not be
    too great.

30. Fixed a bug in callout caching. If a RCPT command caused the sender address
    to be verified with callout=postmaster, and the main callout worked but the
    postmaster check failed, the verification correctly failed. However, if a
    subsequent RCPT command asked for sender verification *without* the
    postmaster check, incorrect caching caused this verification also to fail,
    incorrectly.

31. Exim caches DNS lookup failures so as to avoid multiple timeouts; however,
    it was not caching the DNS options (qualify_single, search_parents) that
    were used when the lookup failed. A subsequent lookup with different
    options therefore always gave the same answer, though there were cases
    where it should not have. (Example: a "domains = !$mx_any" option on a
    dnslookup router: the "domains" option is always processed without any
    widening, but the router might have qualify_single set.) Now Exim uses the
    cached value only when the same options are set.

32. Added John Jetmore's "exipick" utility to the distribution.

33. GnuTLS: When an attempt to start a TLS session fails for any reason other
    than a timeout (e.g. a certificate is required, and is not provided), an
    Exim server now closes the connection immediately. Previously it waited for
    the client to close - but if the client is SSL, it seems that they each
    wait for each other, leading to a delay before one of them times out.

34: GnuTLS: Updated the code to use the new GnuTLS 1.0.0 API. I have not
    maintained 0.8.x compatibility because I don't think many are using it, and
    it is clearly obsolete.

35. Added TLS support for CRLs: a tls_crl global option and one for the smtp
    transport.

36. OpenSSL: $tls_certificate_verified was being set to 1 even if the
    client certificate was expired. A simple patch fixes this, though I don't
    understand the full logic of why the verify callback is called multiple
    times.

37. OpenSSL: a patch from Robert Roselius: "Enable client-bug workaround.
    Versions of OpenSSL as of 0.9.6d include a 'CBC countermeasure' feature,
    which causes problems with some clients (such as the Certicom SSL Plus
    library used by Eudora). This option, SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS,
    disables the coutermeasure allowing Eudora to connect."

38. Exim was not checking that a write() to a log file succeeded. This could
    lead to Bad Things if a log got too big, in particular if it hit a file
    size limit. Exim now panics and dies if it cannot write to a log file, just
    as it does if it cannot open a log file.

39. Modified OS/Makefile-Linux so that it now contains

      CFLAGS=-O -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE

    The two -D definitions ensure that Exim is compiled with large file
    support, which makes it possible to handle log files that are bigger than
    2^31.

40. Fixed a subtle caching bug: if (in an ACL or a set of routers, for
    instance) a domain was checked against a named list that involved a lookup,
    causing $domain_data to be set, then another domain was checked against the
    same list, then the first domain was re-checked, the value of $domain_data
    after the final check could be wrong. In particular, if the second check
    failed, it could be set empty. This bug probably also applied to
    $localpart_data.

41. The strip_trailing_dot option was not being applied to the address given
    with the -f command-line option.

42. The code for reading a message's header from the spool was incrementing
    $received_count, but never initializing it. This meant that the value was
    incorrect (doubled) while delivering a message in the same process in which
    it was received. In the most common configuration of Exim, this never
    happens - a fresh exec is done - but it can happen when
    deliver_drop_privilege is set.

43. When Exim logs an SMTP synchronization error - client data sent too soon -
    it now includes up to 150 characters of the unexpected data in the log
    line.

44. The exim_dbmbuild utility uses fixed size buffers for reading input lines
    and building data strings. The size of both of these buffers was 10 000
    bytes - far larger than anybody would *ever* want, thought I. Needless to
    say, somebody hit the limit. I have increased the maximum line length to
    20 000 and the maximum data length of concatenated lines to 100 000. I have
    also fixed two bugs, because there was no checking on these buffers. Tsk,
    tsk. Now exim_dbmbuild gives a message and exits with an error code if a
    buffer is too small.

45. The exim_dbmbuild utility did not support quoted keys, as Exim does in
    lsearch lookups. Now it does.

46. When parsing a route_list item in a manualroute router, a fixed-length
    buffer was used for the list of hosts. I made this 1024 bytes long,
    thinking that nobody would ever have a list of hosts that long. Wrong.
    Somebody had a whole pile of complicated expansion conditions, and the
    string was silently truncated, leading to an expansion error. It turns out
    that it is easier to change to an unlimited length (owing to other changes
    that have happened since this code was originally written) than to build
    structure for giving a limitation error. The length of the item that
    expands into the list of hosts is now unlimited.

47. The lsearch lookup could not handle data where the length of text line was
    more than 4095 characters. Such lines were truncated, leading to shortened
    data being returned. It should now handle lines of any length.

48. Minor wording revision: "cannot test xxx in yyy ACL" becomes "cannot test
    xxx condition in yyy ACL" (e.g. "cannot test domains condition in DATA
    ACL").

49. Cosmetic tidy to scripts like exicyclog that are generated by globally
    replacing strings such as BIN_DIRECTORY in a source file: the replacement
    no longer happens in comment lines. A list of replacements is now placed
    at the head of all of the source files, except those whose only change is
    to replace PERL_COMMAND in the very first #! line.

50. Replaced the slow insertion sort in queue.c, for sorting the list of
    messages on the queue, with a bottom-up merge sort, using code contributed
    by Michael Haardt. This should make operations like -bp somewhat faster on
    large queues. It won't affect queue runners, except when queue_run_in_order
    is set.

51. Installed eximstats 1.31 in the distribution.

52. Added support for SRV lookups to the dnslookup router.

53. If an ACL referred to $message_body or $message_body_end, the value was not
    reset for any messages that followed in the same SMTP session.

54. The store-handling optimization for building very long strings was not
    differentiating between the different store pools. I don't think this
    actually made any difference in practice, but I've tidied it.

55. While running the routers to verify a sender address, $sender_address
    was still set to the sender address. This is wrong, because when routing to
    send a bounce to the sender, it would be empty. Therefore, I have changed
    it so that, while verifying a sender address, $sender_address is set to <>.
    (There is no change to what happens when verifying a recipient address.)

56. After finding MX (or SRV) records, Exim was doing a DNS lookup for the
    target A or AAAA records (if not already returned) without resetting the
    qualify_single or search_parents options of the DNS resolver. These are
    inappropriate in this case because the targets of MX and SRV records must
    be FQDNs. A broken DNS record could cause trouble if it happened to have a
    target that, when qualified, matched something in the local domain. These
    two options are now turned off when doing these lookups.

57. It seems that at least some releases of Reiserfs (which does not have the
    concept of a fixed number of inodes) returns zero and not -1 for the
    number of available inodes. This interacted badly with check_spool_inodes,
    which assumed that -1 was the "no such thing" setting. What I have done is
    to check that the total number of inodes is greater than zero before doing
    the test of how many are available.

58. When a "warn" ACL statement has a log_message modifier, the message is
    remembered, and not repeated. This is to avoid a lot of repetition when a
    message has many recipients that cause the same warning to be written.
    However, Exim was preserving the list of already written lines for an
    entire SMTP session, which doesn't seem right. The memory is now reset if a
    new message is started.

59. The "rewrite" debugging flag was not showing the result of rewriting in the
    debugging output unless log_rewrite was also set.

60. Avoid a compiler warning on 64-bit systems in dsearch.c by avoiding the use
    of (int)(handle) when we know that handle contains (void *)(-1).

61. The Exim daemon panic-logs an error return when it closes the incoming
    connection. However "connection reset by peer" seems to be common, and
    isn't really an error worthy of noting specially, so that particular error
    is no long logged.

62. When Exim is trying to find all the local interfaces, it used to panic and
    die if the ioctl to get the interface flags failed. However, it seems that
    on at least one OS (Solaris 9) it is possible to have an interface that is
    included in the list of interfaces, but for which you get a failure error
    for this call. This happens when the interface is not "plumbed" into a
    protocol (i.e. neither IPv4 nor IPv6). I've changed the code so that a
    failure of the "get flags" call assumes that the interface is down.

63. Added a ${eval10: operator, which assumes all numbers are decimal. This
    makes life easier for people who are doing arithmetic on fields extracted
    from dates, where you often get leading zeros that should not be
    interpreted as octal.

64. Added qualify_domain to the redirect router, to override the global
    setting.

65. If a pathologically long header line contained very many addresses (the
    report of this problem mentioned 10 000) and each of them was rewritten,
    Exim could use up a very large amount of memory. (It kept on making new
    copies of the header line as it rewrote, and never released the old ones.)
    At the expense of a bit more processing, the header rewriting function has
    been changed so that it no longer eats memory in this way.

66. The generation of the Received: header has been moved from the time that a
    message starts to be received, to the time that it finishes. The timestamp
    in the Received: header should now be very close to that of the <= log
    line. There are two side-effects of this change:

    (a) If a message is rejected by a DATA or non-SMTP ACL or local_scan(), the
        logged header lines no longer include the local Received: line, because
        it has not yet been created. The same applies to a copy of the message
        that is returned to a non-SMTP sender when a message is rejected.

    (b) When a filter file is tested using -bf, no additional Received: header
        is added to the test message. After some thought, I decided that this
        is a bug fix.

    This change does not affect the value of $received_for. It is still set
    after address rewriting, but before local_scan() is called.

67. Installed the latest Cygwin-specific files from the Cygwin maintainer.

68. GnuTLS: If an empty file is specified for tls_verify_certificates, GnuTLS
    gave an unhelpful panic error message, and a defer error. I have managed to
    change this behaviour so that it now rejects any supplied certificate,
    which seems right, as the list of acceptable certificates is empty.

69. OpenSSL: If an empty file is specified for tls_verify_certificates, OpenSSL
    gave an unhelpful defer error. I have not managed to make this reject any
    supplied certificates, but the error message it gives is "no certificate
    supplied", which is not helpful.

70. exigrep's output now also includes lines that are not associated with any
    message, but which match the given pattern. Implemented by a patch from
    Martin Sluka, which also tidied up the Perl a bit.

71. Recipient callout verification, like sender verification, was using <> in
    the MAIL FROM command. This isn't really the right thing, since the actual
    sender may affect whether the remote host accepts the recipient or not. I
    have changed it to use the actual sender in the callout; this means that
    the cache record is now keyed on a recipient/sender pair, not just the
    recipient address. There doesn't seem to be a real danger of callout loops,
    since a callout by the remote host to check the sender would use <>.
    [SEE ABOVE: changed after hitting problems.]

72. Exim treats illegal SMTP error codes that do not begin with 4 or 5 as
    temporary errors. However, in the case of such a code being given after
    the end of a data transmission (i.e. after ".") Exim was failing to write
    a retry record for the message. (Yes, there was some broken host that was
    actually sending 8xx at this point.)

73. An unknown lookup type in a host list could cause Exim to panic-die when
    the list was checked. (An example that provoked this was putting <; in the
    middle of a list instead of at the start.) If this happened during a DATA
    ACL check, a -D file could be left lying around. This kind of configuration
    error no longer causes Exim to die; instead it causes a defer error. The
    incident is still logged to the main and panic logs.

74. Buglet left over from Exim 3 conversion. The message "too many messages
    in one connection" was written to the rejectlog but not the mainlog, except
    when address rewriting (yes!) was being logged.

75. Added write_rejectlog option.

76. When a system filter was run not as root (that is, when system_filter_user
    was set), the values of the $n variables were not being returned to the
    main process; thus, they were not subsequently available in the $sn
    variables.

77. Added +return_path_on_delivery log selector.

78. A connection timeout was being treated differently from recipients deferred
    when testing hosts_max_try with a message that was older than the host's
    retry timeout. (The host should not be counted, thus allowing all hosts to
    be tried at least once before bouncing.) This may have been the cause of an
    occasionally reported bug whereby a message would remain on the queue
    longer than the retry timeout, but would be bounced if a delivery was
    forced. I say "may" because I never totally pinned down the problem;
    setting up timeout/retry tests is difficult. See also the next item.

79. The ultimate address timeout was not being applied to errors that involved
    a combination of host plus message (for example, a timeout on a MAIL
    command). When an address resolved to a number of possible hosts, and they
    were not all tried for each delivery (e.g. because of hosts_max_try), a
    message could remain on the queue longer than the retry timeout.

80. Sieve bug: "stop" inside "elsif" was broken. Applied a patch from Michael
    Haardt.

81. Fixed an obscure SMTP outgoing bug which required at least the following
    conditions: (a) there was another message waiting for the same server;
    (b) the server returned 5xx to all RCPT commands in the first message so
    that the message was not completed; (c) the server dropped the connection
    or gave a negative response to the RSET that Exim sends to abort the
    transaction. The observed case was a dropped connection after DATA that had
    been sent in pipelining mode. That is, the server had advertised PIPELINING
    but was not implementing it correctly. The effect of the bug was incorrect
    behaviour, such as trying another host, and this could lead to a crash.


Exim version 4.30
-----------------

 1. The 3rd arguments to getsockname(), getpeername(), and accept() in exim.c
    and daemon.c were passed as pointers to ints; they should have been
    pointers to socklen_t variables (which are typically unsigned ints).

 2. Some signed/unsigned type warnings in the os.c file for Linux have been
    fixed.

 3. Fixed a really odd bug that affected only the testing scheme; patching a
    certain fixed string in the binary changed the value of another string that
    happened to be identical to the end of the original first string.

 4. When gethostbyname() (or equivalent) is passed an IP address as a "host
    name", it returns that address as the IP address. On some operating
    systems (e.g. Solaris), it also passes back the IP address string as the
    "host name". However, on others (e.g. Linux), it passes back an empty
    string. Exim wasn't checking for this, and was changing the host name to an
    empty string, assuming it had been canonicalized.

 5. Although rare, it is permitted to have more than one PTR record for a given
    IP address. I thought that gethostbyaddr() or getipnodebyaddr() always gave
    all the names associated with an address, because they do in Solaris.
    However, it seems that they do not in Linux for data that comes from the
    DNS. If an address in /etc/hosts has multiple names, they _are_ all given.
    I found this out when I moved to a new Linux workstation and tried to run
    the Exim test suite.

    To get round this problem I have changed the code so that it now does its
    own call to the DNS to look up PTR records when searching for a host name.
    If nothing can be found in the DNS, it tries gethostbyaddr(), so that
    addresses that are only in /etc/hosts are still found.

    This behaviour is, however, controlled by an option called host_lookup_
    order, which defaults to "bydns:byaddr". If people want to use the other
    order, or indeed, just use one or the other means of lookup, they can
    specify it in this variable.

 6. If a PTR record yields an empty name, Exim treats it as non-existent. In
    some operating systems, this comes back from gethostbyaddr() as an empty
    string, and this is what Exim used to test for. However, it seems that in
    other systems, "." is yielded. Exim now tests for this case too.

 7. The values of check_spool_space and check_log_space are now held internally
    as a number of kilobytes instead of an absolute number of bytes. If a
    numbers is specified without 'K' or 'M', it is rounded up to the nearest
    kilobyte. This means that much larger values can be stored.

 8. Exim monitor: an attempt to get the action menu when not actually pointing
    at a message produces an empty menu entitled "No message selected". This
    works on Solaris (OpenWindows). However, XFree86 does not like a menu with
    no entries in it ("Shell widget menu has zero width and/or height"). So I
    have added a single, blank menu entry in this case.

 9. Added ${quote_local_part.

10. MIME decoding is now applied to the contents of Subject: header lines when
    they are logged.

11. Now that a reference to $sender_host_address automatically causes a reverse
    lookup to occur if necessary (4.13/18), there is no need to arrange for a
    host lookup before query-style lookups in lists that might use this
    variable. This has therefore been abolished, and the "net-" prefix is no
    longer necessary for query-style lookups.

12. The Makefile for SCO_SV contained a setting of LDFLAGS. This appears to
    have been a typo for LFLAGS, so it has been changed.

13. The install script calls Exim with "-C /dev/null" in order to find the
    version number. If ALT_CONFIG_PREFIX was set, this caused an error message
    to be output. However, since Exim outputs its version number before the
    error, it didn't break the script. It just looked ugly. I fixed this by
    always allowing "-C /dev/null" if the caller is root.

14. Ignore overlarge ACL variable number when reading spool file - insurance
    against a later release with more variables having written the file.

15. The standard form for an IPv6 address literal was being rejected by EHLO.
    Example: [IPv6:2002:c1ed:8229:10:202:2dff:fe07:a42a]. Exim now accepts
    this, as well as the form without the "IPv6" on the front.

16. Added CHOWN_COMMAND=/usr/sbin/chown and LIBS=-lresolv to the
    OS/Makefile-Darwin file.

17. Fixed typo in lookups/ldap.c: D_LOOKUP should be D_lookup. This applied
    only to LDAP libraries that do not have LDAP_OPT_DEREF.

18. After change 4.21/52, "%ld" was used to format the contents of the $inode
    variable. However, some OS use ints for inodes. I've added cast to long int
    to get rid of the compiler warning.

19. I had forgotten to lock out "/../" in configuration file names when
    ALT_CONFIG_PREFIX was set.

20. Routers used for verification do not need to specify transports. However,
    if such a router generated a host list, and callout was configured, Exim
    crashed, because it could not find a port number from the (non-existent)
    transport. It now assumes port 25 in this circumstance.

21. Added the -t option to exigrep.

22. If LOOKUP_LSEARCH is defined, all three linear search methods (lsearch,
    wildlsearch, nwildlsearch) are compiled. LOOKUP_WILDLSEARCH and LOOKUP_
    NWILDLSEARCH are now obsolete, but retained for compatibility. If either of
    them is set, LOOKUP_LSEARCH is forced.

23. "exim -bV" now outputs a list of lookups that are included in the binary.

24. Added sender and host information to the "rejected by local_scan()" log
    line; previously there was no indication of these.

25. Added .include_if_exists.

26. Change 3.952/11 added an explicit directory sync on top of a file sync for
    Linux. It turns out that not all file systems support this. Apparently some
    versions of NFS do not. (It's rare to put Exim's spool on NFS, but people
    do it.) To cope with this, the error EINVAL, which means that sync-ing is
    not supported on the file descriptor, is now ignored when Exim is trying to
    sync a directory. This applies only to Linux.

27. Added -DBIND_8_COMPAT to the CLFAGS setting for Darwin.

28. In Darwin (MacOS X), the PAM headers are in /usr/include/pam and not in
    /usr/include/security. There's now a flag in OS/os.h-Darwin to cope with
    this.

29. Added support for maildirsize files from supplied patch (modified a bit).

30. The use of :fail: followed by an empty string could lead Exim to respond to
    sender verification failures with (e.g.):

      550 Verification failed for <xxx>
      550 Sender verify failed

    where the first response line was missing the '-' that indicates it is not
    the final line of the response.

31. The loop for finding the name of the user that called Exim had a hardwired
    limit of 10; it now uses the value of finduser_retries, which is used for
    all other user lookups.

32. Added $received_count variable, available in data and not_smtp ACLs, and at
    delivery time.

33. Exim was neglecting to zero errno before one call of strtol() when
    expanding a string and expecting an integer value. On some systems this
    resulted in spurious "integer overflow" errors. Also, it was casting the
    result into an int without checking.

34. Testing for a connection timeout using "timeout_connect" in the retry rules
    did not work. The code looks as if it has *never* worked, though it appears
    to have been documented since at least release 1.62. I have made it work.

35. The "timeout_DNS" error in retry rules, also documented since at least
    1.62, also never worked. As it isn't clear exactly what this means, and
    clearly it isn't a major issue, I have abolished the feature by treating it
    as "timeout", and writing a warning to the main and panic logs.

36. The display of retry rules for -brt wasn't always showing the error code
    correctly.

37. Added new error conditions to retry rules: timeout_A, timeout_MX,
    timeout_connect_A, timeout_connect_MX.

38. Rewriting the envelope sender at SMTP time did not allow it to be rewritten
    to the empty sender.

39. The daemon was not analysing the content of -oX till after it had closed
    stderr and disconnected from the controlling terminal. This meant that any
    syntax errors were only noted on the panic log, and the return code from
    the command was 0. By re-arranging the code a little, I've made the
    decoding happen first, so such errors now appear on stderr, and the return
    code is 1. However, the actual setting up of the sockets still happens in
    the disconnected process, so errors there are still only recorded on the
    panic log.

40. A daemon listener on a wildcard IPv6 socket that also accepts IPv4
    connections (as happens on some IP stacks) was logged at start up time as
    just listening for IPv6. It now logs "IPv6 with IPv4". This differentiates
    it from "IPv6 and IPv4", which means that two separate sockets are being
    used.

41. The debug output for gethostbyname2() or getipnodebyname() failures now
    says whether AF_INET or AF_INET6 was passed as an argument.

42. Exiwhat output was messed up when time zones were included in log
    timestamps.

43. Exiwhat now gives more information about the daemon's listening ports,
    and whether -tls-on-connect was used.

44. The "port" option of the smtp transport is now expanded.

45. A "message" modifier in a "warn" statement in a non-message ACL was being
    silently ignored. Now an error message is written to the main and panic
    logs.

46. There's a new ACL modifier called "logwrite" which writes to a log file
    as soon as it is encountered.

47. Added $local_user_uid and $local_user_gid at routing time.

48. Exim crashed when trying to verify a sender address that was being
    rewritten to "<>".

49. Exim was recognizing only a space character after ".include". It now also
    recognizes a tab character.

50. Fixed several bugs in the Perl script that creates the exim.8 man page by
    extracting the relevant information from the specification. The man page no
    longer contains scrambled data for the -d option, and I've added a section
    at the front about calling Exim under different names.

51. Added "extra_headers" argument to the "mail" command in filter files.

52. Redirecting mail to an unqualified address in a Sieve filter caused Exim to
    crash.

53. Installed eximstats 1.29.

54. Added transport_filter_timeout as a generic transport option.

55. Exim no longer adds an empty Bcc: header to messages that have no To: or
    Cc: header lines. This was required by RFC 822, but it not required by RFC
    2822.

56. Exim used to add From:, Date:, and Message-Id: header lines to any
    incoming messages that did not have them. Now it does so only if the
    message originates locally, that is, if there is no associated remote host
    address. When Resent- header lines are present, this applies to the Resent-
    lines rather than the non-Resent- lines.

57. Drop incoming SMTP connection after too many syntax or protocol errors. The
    limit is controlled by smtp_max_synprot_errors, defaulting to 3.

58. Messages for configuration errors now include the name of the main
    configuration file - useful now that there may be more than one file in a
    list (.included file names were always shown).

59. Change 4.21/82 (run initgroups() when starting the daemon) causes problems
    for those rare installations that do not start the daemon as root or run it
    setuid root. I've cut out the call to initgroups() if the daemon is not
    root at that time.

60. The Exim user and group can now be bound into the binary as text strings
    that are looked up at the start of Exim's processing.

61. Applied a small patch for the Interbase code, supplied by Ard Biesheuvel.

62. Added $mailstore_basename variable.

63. Installed patch to sieve.c from Michael Haardt.

64. When Exim failed to open the panic log after failing to open the main log,
    the original message it was trying to log was written to stderr and debug
    output, but if they were not available (the usual case in production), it
    was lost. Now it is written to syslog before the two lines that record the
    failures to open the logs.

65. Users' Exim filters run in subprocesses under the user's uid. It is
    possible for a "deliver" command or an alias in a "personal" command to
    provoke an address rewrite. If logging of address rewriting is configured,
    this fails because the process is not running as root or exim. There may be
    a better way of dealing with this, but for the moment (because 4.30 needs
    to be released), I have disabled address rewrite logging when running a
    filter in a non-root, non-exim process.


Exim version 4.24
-----------------

 1. The buildconfig auxiliary program wasn't quoting the value set for
    HEADERS_CHARSET. This caused a compilation error complaining that 'ISO' was
    not defined. This bug was masked in 4.22 by the effect that was fixed in
    change 4.23/1.

 2. Some messages that were rejected after a message id was allocated were
    shown as "incomplete" by exigrep. It no longer does this for messages that
    are rejected by local_scan() or the DATA or non-SMTP ACLs.

 3. If a Message-ID: header used a domain literal in the ID, and Exim did not
    have allow_domain_literals set, the ID did not get logged in the <= line.
    Domain literals are now always recognized in Message-ID: header lines.

 4. The first argument for a ${extract expansion item is the key name or field
    number. Leading and trailing spaces in this item were not being ignored,
    causing some misleading effects.

 5. When deliver_drop_privilege was set, single queue runner processes started
    manually (i.e. by the command "exim -q") or by the daemon (which uses the
    same command in the process it spins off) were not dropping privilege.

 6. When the daemon running as "exim" started a queue runner, it always
    re-executed Exim in the spun-off process. This is a waste of effort when
    deliver_drop_privilege is set. The new process now just calls the
    queue-runner function directly.


Exim version 4.23
-----------------

 1. Typo in the src/EDITME file: it referred to HEADERS_DECODE_TO instead of
    HEADERS_CHARSET.

 2. Change 4.21/73 introduced a bug. The pid file path set by -oP was being
    ignored. Though the use of -oP was forcing the writing of a pid file, it
    was always written to the default place.

 3. If the message "no IP address found for host xxxx" is generated during
    incoming verification, it is now followed by identification of the incoming
    connection (so you can more easily find what provoked it).

 4. Bug fix for Sieve filters: "stop" inside a block was not working properly.

 5. Added some features to "harden" Exim a bit more against certain attacks:

    (a) There is now a build-time option called FIXED_NEVER_USERS that can
        be put in Local/Makefile. This is like the never_users runtime option,
        but it cannot be overridden. The default setting is "root".

    (b) If ALT_CONFIG_PREFIX is defined in Local/Makefile, it specifies a
        prefix string with which any file named in a -C command line option
        must start.

    (c) If ALT_CONFIG_ROOT_ONLY is defined in Local/Makefile, root privilege
        is retained for -C and -D only if the caller of Exim is root. Without
        it, the exim user may also use -C and -D and retain privilege.

    (d) If DISABLE_D_OPTION is defined in Local/Makefile, the use of the -D
        command line option is disabled.

 6. Macro names set by the -D option must start with an upper case letter, just
    like macro names defined in the configuration file.

 7. Added "dereference=" facility to LDAP.

 8. Two instances of the typo "uknown" in the source files are fixed.

 9. If a PERL_COMMAND setting in Local/Makefile was not at the start of a line,
    the Configure-Makefile script screwed up while processing it.

10. Incorporated PCRE 4.4.

11. The SMTP synchronization check was not operating right at the start of an
    SMTP session. For example, it could not catch a HELO sent before the client
    waited for the greeting. There is now a check for outstanding input at the
    point when the greeting is written. Because of the duplex, asynchronous
    nature of TCP/IP, it cannot be perfect - the incorrect input may be on its
    way, but not yet received, when the check is performed.

12. Added tcp_nodelay to make it possible to turn of the setting of TCP_NODELAY
    on TCP/IP sockets, because this apparently causes some broken clients to
    timeout.

13. Installed revised OS/Makefile-CYGWIN and OS/os.c-cygwin (the .h file was
    unchanged) from the Cygwin maintainer.

14. The code for -bV that shows what is in the binary showed "mbx" when maildir
    was supported instead of testing for mbx. Effectively a typo.

15. The spa authenticator server code was not checking that the input it
    received was valid base64.

16. The debug output line for the "set" modifier in ACLs was not showing the
    name of the variable that was being set.

17. Code tidy: the variable type "vtype_string" was never used. Removed it.

18. Previously, a reference to $sender_host_name did not cause a DNS reverse
    lookup on its own. Something else was needed to trigger the lookup. For
    example, a match in host_lookup or the need for a host name in a host list.
    Now, if $sender_host_name is referenced and the host name has not yet been
    looked up, a lookup is performed. If the lookup fails, the variable remains
    empty, and $host_lookup_failed is set to "1".

19. Added "eqi" as a case-independent comparison operator.

20. The saslauthd authentication condition could segfault if neither service
    nor realm was specified.

21. If an overflowing value such as "2048M" was set for message_size_limit, the
    error message that was logged was misleading, and incoming SMTP
    connections were dropped. The message is now more accurate, and temporary
    errors are given to SMTP connections.

22. In some error situations (such as 21 above) Exim rejects all SMTP commands
    (except RSET) with a 421 error, until QUIT is received. However, it was
    failing to send a response to QUIT.

23. The HELO ACL was being run before the code for helo_try_verify_hosts,
    which made it impossible to use "verify = helo" in the HELO ACL. The HELO
    ACL is now run after the helo_try_verify_hosts code.

24. "{MD5}" and "{SHA1}" are now recognized as equivalent to "{md5"} and
    "{sha1}" in the "crypteq" expansion condition (in fact the comparison is
    case-independent, so other case variants are also recognized). Apparently
    some systems use these upper case variants.

25. If more than two messages were waiting for the same host, and a transport
    filter was specified for the transport, Exim sent two messages over the
    same TCP/IP connection, and then failed with "socket operation on non-
    socket" when it tried to send the third.

26. Added Exim::debug_write and Exim::log_write for embedded Perl use.

27. The extern definition of crypt16() in expand.c was not being excluded when
    the OS had its own crypt16() function.

28. Added bounce_return_body as a new option, and bounce_return_size_limit
    as a preferred synonym for return_size_limit, both as an option and as an
    expansion variable.

29. Added LIBS=-liconv to OS/Makefile-OSF1.

30. Changed the default configuration ACL to relax the local part checking rule
    for addresses that are not in any local domains. For these addresses,
    slashes and pipe symbols are allowed within local parts, but the sequence
    /../ is explicitly forbidden.

31. SPA server authentication was not clearing the challenge buffer before
    using it.

32. log_message in a "warn" ACL statement was writing to the reject log as
    well as to the main log, which contradicts the documentation and doesn't
    seem right (because no rejection is happening). So I have stopped it.

33. Added Ard Biesheuvel's lookup code for accessing an Interbase database.
    However, I am unable to do any testing of this.

34. Fixed an infelicity in the appendfile transport. When checking directories
    for a mailbox, to see if any needed to be created, it was accidentally
    using path names with one or more superfluous leading slashes; tracing
    would show up entries such as stat("///home/ph10", 0xFFBEEA48).

35. If log_message is set on a "discard" verb in a MAIL or RCPT ACL, its
    contents are added to the log line that is written for every discarded
    recipient. (Previously a log_message setting was ignored.)

36. The ${quote: operator now quotes the string if it is empty.

37. The install script runs exim in order to find its version number. If for
    some reason other than non-existence or emptiness, which it checks, it
    could not run './exim', it was installing it with an empty version number,
    i.e. as "exim-". This error state is now caught, and the installation is
    aborted.

38. An argument was missing from the function that creates an error message
    when Exim fails to connect to the socket for saslauthd authentication.
    This could cause Exim to crash, or give a corrupted message.

39. Added isip, isip4, and isip6 to ${if conditions.

40. The ACL variables $acl_xx are now saved with the message, and can be
    accessed later in routers, transports, and filters.

41. The new lookup type nwildlsearch is like wildlsearch, except that the key
    strings in the file are not string-expanded.

42. If a MAIL command specified a SIZE value that was too large to fit into an
    int variable, the check against message_size_limit failed. Such values are
    now forced to INT_MAX, which is around 2Gb for a 32-bit variable. Maybe one
    day this will have to be increased, but I don't think I want to be around
    when emails are that large.



Exim version 4.22
-----------------

 1. Removed HAVE_ICONV=yes from OS/Makefile-FreeBSD, since it seems that
    iconv() is not standard in FreeBSD.

 2. Change 4.21/17 was buggy and could cause stack overwriting on a system with
    IPv6 enabled. The observed symptom was a segmentation fault on return from
    the function os_common_find_running_interfaces() in src/os.c.

 3. In the check_special_case() function in daemon.c I had used "errno" as an
    argument name, which causes warnings on some systems. This was basically a
    typo, since it was named "eno" in the comments!

 4. The code that waits for the clock to tick (at a resolution of some fraction
    of a second) so as to ensure message-id uniqueness was always waiting for
    at least one whole tick, when it could have waited for less. [This is
    almost certainly not relevant at current processor speeds, where it is
    unlikely to ever wait at all. But we try to future-proof.]

 5. The function that sleeps for a time interval that includes fractions of a
    second contained a race. It did not block SIGALRM between setting the
    timer, and suspending (a couple of lines later). If the interval was short
    and the sigsuspend() was delayed until after it had expired, the suspension
    never ended. On busy systems this could lead to processes getting stuck for
    ever.

 6. Some uncommon configurations may cause a lookup to happen in a queue runner
    process, before it forks any delivery processes. The open lookup caching
    mechanism meant that the open file or database connection was passed into
    the delivery process. The problem was that delivery processes always tidy
    up cached lookup data. This could cause a problem for the next delivery
    process started by the queue runner, because the external queue runner
    process does not know about the closure. So the next delivery process
    still has data in the lookup cache. In the case of a file lookup, there was
    no problem because closing a file descriptor in a subprocess doesn't affect
    the parent. However, if the lookup was caching a connection to a database,
    the connection was closed, and the second delivery process was likely to
    see errors such as "PGSQL: query failed: server closed the connection
    unexpectedly". The problem has been fixed by closing all cached lookups
    in a queue runner before running a delivery process.

 7. Compiler warning on Linux for the second argument of iconv(), which doesn't
    seem to have the "const" qualifier which it has on other OS. I've
    parameterised it.

 8. Change 4.21/2 was too strict. It is only if there are two authenticators
    *of the same type* (client or server) with the same public name that an
    error should be diagnosed.

 9. When Exim looked up a host name for an IP address, but failed to find the
    original IP address when looking up the host name (a safety check), it
    output the message "<ip address> does not match any IP for NULL", which was
    confusing, to say the least. The bug was that the host name should have
    appeared instead of "NULL".

10. Since release 3.03, if Exim is called by a uid other than root or the Exim
    user that is built into the binary, and the -C or -D options is used, root
    privilege is dropped before the configuration file is read. In addition,
    logging is switched to stderr instead of the normal log files. If the
    configuration then re-defines the Exim user, the unprivileged environment
    is probably not what is expected, so Exim logs a panic warning message (but
    proceeds).

    However, if deliver_drop_privilege is set, the unprivileged state may well
    be exactly what is intended, so the warning has been cut out in that case,
    and Exim is allowed to try to write to its normal log files.


Exim version 4.21
-----------------

 1. smtp_return_error_details was not giving details for temporary sender
    or receiver verification errors.

 2. Diagnose a configuration error if two authenticators have the same public
    name.

 3. Exim used not to create the message log file for a message until the first
    delivery attempt. This could be confusing when incoming messages were held
    for policy or load reasons. The message log file is now created at the time
    the message is received, and an initial "Received" line is written to it.

 4. The automatically generated man page for command line options had a minor
    bug that caused no ill effects; however, a more serious problem was that
    the procedure for building the man page automatically didn't always
    operate. Consequently, release 4.20 contains an out-of-date version. This
    shouldn't happen again.

 5. When building Exim with embedded Perl support, the script that builds the
    Makefile was calling 'perl' to find its compile-time parameters, ignoring
    any setting of PERL_COMMAND in Local/Makefile. This is now fixed.

 6. The freeze_tell option was not being used for messages that were frozen on
    arrival, either by an ACL or by local_scan().

 7. Added the smtp_incomplete_transaction log selector.

 8. After STARTTLS, Exim was not forgetting that it had advertised AUTH, so it
    was accepting AUTH without a new EHLO.

 9. Added tls_remember_esmtp to cope with YAEB. This allows AUTH and other
    ESMTP extensions after STARTTLS without a new EHLO, in contravention of the
    RFC.

10. Logging of TCP/IP connections (when configured) now happens in the main
    daemon process instead of the child process, so that the TCP/IP connection
    count is more accurate (but it can never be perfect).

11. The use of "drop" in a nested ACL was not being handled correctly in the
    outer ACL. Now, if condition failure induced by the nested "drop" causes
    the outer ACL verb to deny access ("accept" or "discard" after "endpass",
    or "require"), the connection is dropped.

12. Similarly, "discard" in a nested ACL wasn't being handled. A nested ACL
    that yield "discard" can now be used with an "accept" or a "discard" verb,
    but an error is generated for any others (because I can't see a useful way
    to define what should happen).

13. When an ACL is read dynamically from a file (or anywhere else), the lines
    are now processed in the same way as lines in the Exim configuration file.
    In particular, continuation lines are supported.

14. Added the "dnslists = a.b.c!=n.n.n.n" feature.

15. Added -ti meaning -t -i.

16. Check for letters, digits, hyphens, and dots in the names of dnslist
    domains, and warn by logging if others are found.

17. At least on BSD, alignment is not guaranteed for the array of ifreq's
    returned from GIFCONF when Exim is trying to find the list of interfaces on
    a host. The code in os.c has been modified to copy each ifreq to an aligned
    structure in all cases.

    Also, in some cases, the returned ifreq's were being copied to a 'struct
    ifreq' on the stack, which was subsequently passed to host_ntoa(). That
    means the last couple of bytes of an IPv6 address could be chopped if the
    ifreq contained only a normal sockaddr (14 bytes storage).

18. Named domain lists were not supported in the hosts_treat_as_local option.
    An entry such as +xxxx was not recognized, and was treated as a literal
    domain name.

19. Ensure that header lines added by a DATA ACL are included in the reject log
    if the ACL subsequently rejects the message.

20. Upgrade the cramtest.pl utility script to use Digest::MD5 instead of just
    MD5 (which is deprecated).

21. When testing a filter file using -bf, Exim was writing a message when it
    took the sender from a "From " line in the message, but it was not doing so
    when it took $return_path from a Return-Path: header line. It now does.

22. If the contents of a "message" modifier for a "warn" ACL verb do not begin
    with a valid header line field name (a series of printing characters
    terminated by a colon, Exim now inserts X-ACL-Warn: at the beginning.

23. Changed "disc" in the source to "disk" to conform to the documentation and
    the book and for uniformity.

24. Ignore Sendmail's -Ooption=value command line item.

25. When execve() failed while trying to run a command in a pipe transport,
    Exim was returning EX_UNAVAILABLE (69) from the subprocess. However, this
    could be confused with a return value of 69 from the command itself. This
    has been changed to 127, the value the shell returns if it is asked to run
    a non-existent command. The wording for the related log line suggests a
    non-existent command as the problem.

26. If received_header_text expands to an empty string, do not add a Received:
    header line to the message. (Well, it adds a token one on the spool, but
    marks it "old" so that it doesn't get used or transmitted.)

27. Installed eximstats 1.28 (addition of -nt option).

28. There was no check for failure on the call to getsockname() in the daemon
    code. This can fail if there is a shortage of resources on the system, with
    ENOMEM, for example. A temporary error is now given on failure.

29. Contrary to the C standard, it seems that in some environments, the
    equivalent of setlocale(LC_ALL, "C") is not obeyed at the start of a C
    program. Exim now does this explicitly; it affects the formatting of
    timestamps using strftime().

30. If exiqsumm was given junk data, it threw up some uninitialized variable
    complaints. I've now initialized all the variables, to avoid this.

32. Header lines added by a system filter were not being "seen" during
    transport-time rewrites.

33. The info_callback() function passed to OpenSSL is set up with type void
    (*)(SSL *, int, int), as described somewhere. However, when calling the
    function (actually a macro) that sets it up, the type void(*)() is
    expected. I've put in a cast to prevent warnings from picky compilers.

34. If a DNS black list lookup found a CNAME record, but there were no A
    records associated with the domain it pointed at, Exim crashed.

35. If a DNS black list lookup returned more than one A record, Exim ignored
    all but the first. It now scans all returned addresses if a particular IP
    value is being sought. In this situation, the contents of the
    $dnslist_value variable are a list of all the addresses, separated by a
    comma and a space.

36. Tightened up the rules for host name lookups using reverse DNS. Exim used
    to accept a host name and all its aliases if the forward lookup for any of
    them yielded the IP address of the incoming connection. Now it accepts only
    those names whose forward lookup yields the correct IP address. Any other
    names are discarded. This closes a loophole whereby a rogue DNS
    administrator could create reverse DNS records to break through a
    wildcarded host restriction in an ACL.

37. If a user filter or a system filter that ran in a subprocess used any of
    the numerical variables ($1, $2 etc), or $thisaddress, in a pipe command,
    the wrong values were passed to the pipe command ($thisaddress had the
    value of $0, $0 had the value of $1, etc). This bug was introduced by
    change 4.11/101, and not discovered because I wrote an inadequate test. :-(

38. Improved the line breaking for long SMTP error messages from ACLs.
    Previously, if there was no break point between 40 and 75 characters, Exim
    left the rest of the message alone. Two changes have been made: (a) I've
    reduced the minimum length to 35 characters; (b) if it can't find a break
    point between 35 and 75 characters, it looks ahead and uses the first one
    that it finds. This may give the occasional overlong line, but at least the
    remaining text gets split now.

39. Change 82 of 4.11 was unimaginative. It assumed the limit on the number of
    file descriptors might be low, and that setting 1000 would always raise it.
    It turns out that in some environments, the limit is already over 1000 and
    that lowering it causes trouble. So now Exim takes care not to decrease it.

40. When delivering a message, the value of $return_path is set to $sender_
    address at the start of routing (routers may change the value). By an
    oversight, this default was not being set up when an address was tested by
    -bt or -bv, which affected the outcome if any router or filter referred to
    $return_path.

41. The idea of the "warn" ACL verb is that it adds a header or writes to the
    log only when "message" or "log_message" are set. However, if one of the
    conditions was an address verification, or a call to a nested ACL, the
    messages generated by the underlying test were being passed through. This
    no longer happens. The underlying message is available in $acl_verify_
    message for both "message" and "log_message" expansions, so it can be
    passed through if needed.

42. Added RFC 2047 interpretation of header lines for $h_ expansions, with a
    new expansion $bh_ to give the encoded byte string without charset
    translation. Translation happens only if iconv() is available; HAVE_ICONV
    indicates this at build time. HEADERS_CHARSET gives the charset to
    translate to; headers_charset can change it in the configuration, and
    "headers charset" can change it in an individual filter file.

43. Now that we have a default RFC 2047 charset (see above), the code in Exim
    that creates RFC 2047 encoded "words" labels them as that charset instead
    of always using iso-8859-1. The cases are (i) the explicit ${rfc2047:
    expansion operator; (ii) when Exim creates a From: line for a local
    message; (iii) when a header line is rewritten to include a "phrase" part.

44. Nasty bug in exiqsumm: the regex to skip already-delivered addresses was
    buggy, causing it to skip the first lines of messages whose message ID
    ended in 'D'. This would not have bitten before Exim release 4.14, because
    message IDs were unlikely to end in 'D' before then. The effect was to have
    incorrect size information for certain domains.

45. #include "config.h" was missing at the start of the crypt16.c module. This
    caused trouble on Tru64 (aka OSF1) systems, because HAVE_CRYPT16 was not
    noticed.

46. If there was a timeout during a "random" callout check, Exim treated it as
    a failure of the random address, and carried on sending RSET and the real
    address. If the delay was just some slowness somewhere, the response to the
    original RCPT would be taken as a response to RSET and so on, causing
    mayhem of various kinds.

47. Change 50 for 4.20 was a heap of junk. I don't know what I was thinking
    when I implemented it. It didn't allow for the fact that some option values
    may legitimately be negative (e.g. size_addition), and it didn't even do
    the right test for positive values.

48. Domain names in DNS records are case-independent. Exim always looks them up
    in lower case. Some resolvers return domain names in exactly the case they
    appear in the zone file, that is, they may contain uppercase letters. Not
    all resolvers do this - some return always lower case. Exim was treating a
    change of case by a resolver as a change of domain, similar to a widening
    of a domain abbreviation. This triggered its re-routing code and so it was
    trying to route what was effectively the same domain again. This normally
    caused routing to fail (because the router wouldn't handle the domain
    twice). Now Exim checks for this case specially, and just changes the
    casing of the domain that it ultimately uses when it transmits the message
    envelope.

49. Added Sieve (RFC 3028) support, courtesy of Michael Haardt's contributed
    module.

50. If a filter generated a file delivery with a non-absolute name (possible if
    no home directory exists for the router), the forbid_file option was not
    forbidding it.

51. Added '&' feature to dnslists, to provide bit mask matching in addition to
    the existing equality matching.

52. Exim was using ints instead of ino_t variables in some places where it was
    dealing with inode numbers.

53. If TMPDIR is defined in Local/Makefile (default in src/EDITME is
    TMPDIR="/tmp"), Exim checks for the presence of an environment variable
    called TMPDIR, and if it finds it is different, it changes its value.

54. The smtp_printf() function is now made available to local_scan() so
    additional output lines can be written before returning. There is also an
    smtp_fflush() function to enable the detection of a dropped connection.
    The variables smtp_input and smtp_batched_input are exported to
    local_scan().

55. Changed the default runtime configuration: the message "Unknown user"
    has been removed from the ACL, and instead placed on the localuser router,
    using the cannot_route_message feature. This means that any verification
    failures that generate their own messages won't get overridden. Similarly,
    the "Unrouteable address" message that was in the ACL for unverifiable
    relay addresses has also been removed.

56. Added hosts_avoid_esmtp to the smtp transport.

57. The exicyclog script was not checking for the esoteric option
    CONFIGURE_FILE_USE_EUID in the Local/Makefile. It now does this, but it
    will work only if exicyclog is run under the appropriate euid.

58. Following a discussion on the list, the rules by which Exim recognises line
    endings on incoming messages have been changed. The -dropcr and drop_cr
    options are now no-ops, retained only for backwards compatibility. The
    following line terminators are recognized: LF CRLF CR. However, special
    processing applies to CR:

    (i)  The sequence CR . CR does *not* terminate an incoming SMTP message,
         nor a local message in the state where . is a terminator.

    (ii) If a bare CR is encountered in a header line, an extra space is added
         after the line terminator so as not to end the header. The reasoning
         behind this is that bare CRs in header lines are most likely either
         to be mistakes, or people trying to play silly games.

59. The size of a message, as listed by "-bp" or in the Exim monitor window,
    was being incorrectly given as 18 bytes larger than it should have been.
    This is a VOB (very old bug).

60. This may never have affected anything current, but just in case it has:
    When the local host is found other than at the start of a list of hosts,
    the local host, those with the same MX, and any that follow, are discarded.
    When the list in question was part of a longer list of hosts, the following
    hosts (not currently being processed) were also being discarded. This no
    longer happens. I'm not sure if this situation could ever has previously
    arisen.

61. Added the "/MX" feature to lists of hosts in the manualroute and query
    program routers.

62. Whenever Exim generates a new message, it now adds an Auto-Submitted:
    header. This is something that is recommended in a new Internet Draft, and
    is something that is documented as being done by Sendmail. There are two
    possible values. For messages generated by the autoreply transport, Exim
    adds:

      Auto-Submitted: auto-replied

    whereas for all other generated messages (e.g. bounces) it adds

      Auto-Submitted: auto-generated

63. The "personal" condition in filters now includes a test for the
    Auto-Submitted: header. If it contains the string "auto-" the message it
    not considered personal.

64. Added rcpt_include_affixes as a generic transport option.

65. Added queue_only_override (default true).

66. Added the syslog_duplication option.

67. If what should have been the first header line of a message consisted of
    a space followed by a colon, Exim was mis-interpreting it as a header line.
    It isn't of course - it is syntactically invalid and should therefore be
    treated as the start of the message body. The misbehaviour could have
    caused a number of strange effects, including loss of data in subsequent
    header lines, and spool format errors.

68. Formerly, the AUTH parameter on a MAIL command was trusted only if the
    client host had authenticated. This control can now be exercised by an ACL
    for more flexibility.

69. By default, callouts do not happen when testing with -bh. There is now a
    variant, -bhc, which does actually run the callout code, including
    consulting and updating the callout cache.

70. Added support for saslauthd authentication, courtesy of Alexander
    Sabourenkov.

71. If statvfs() failed on the spool or log directories while checking their
    size for availability, Exim confusingly gave the error "space shortage".
    Furthermore, in debugging mode it crashed with a floating point exception.
    These checks are done if check_{spool,log}_{space,inodes} are set, and when
    an SMTP message arrives with SIZE= on the MAIL command. As this is a really
    serious problem, Exim now writes to the main and panic logs when this
    happens, with details of the failure. It then refuses to accept the
    incoming message, giving the message "spool directory problem" or "log
    directory problem" with a 421 code for SMTP messages.

72. When Exim is about to re-exec itself, it ensures that the file descriptors
    0, 1, and 2 exist, because some OS complain for execs without them (see
    ChangeLog 4.05/30). If necessary, Exim opens /dev/null to use for these
    descriptors. However, the code omitted to check that the open succeeded,
    causing mysterious errors if for some reason the permissions on /dev/null
    got screwed. Now Exim writes a message to the main and panic logs, and
    bombs out if it can't open /dev/null.

73. Re-vamped the way daemon_smtp_port, local_interfaces, and -oX work and
    interact so that it is all more flexible. It is supposed to remain
    backwards compatible. Also added extra_local_interfaces.

74. Invalid data sent to a SPA (NTLM) server authenticator could cause the code
    to bomb out with an assertion failure - to the client this appears as a
    connection drop. This problem occurs in the part of the code that was taken
    from the Samba project. Fortunately, the assertion is in a very simple
    function, so I have fixed this by reproducing the function inline in the
    one place where it is called, and arranging for authentication to fail
    instead of killing the process with assert().

75. The SPA client code was not working when the server requested OEM rather
    than Unicode encoding.

76. Added code to make require_files with a specific uid setting more usable in
    the case where statting the file as root fails - usually a non-root-mounted
    NFS file system. When this happens and the failure is EACCES, Exim now
    forks a subprocess and does the per-uid checking as the relevant uid.

77. Added process_log_path.

78. If log_file_path was not explicitly set, a setting of check_log_space or
    check_log_inodes was ignored.

79. If a space check for the spool or log partitions fails, the incident is now
    logged. Of course, in the latter case the data may get lost...

80. Added the %p formatting code to string_format() so that it can be used to
    print addresses in debug_print(). Adjusted all the address printing in the
    debugging in store.c to use %p rather than %d.

81. There was a concern that a line of code in smtp_in.c could overflow a
    buffer if a HELO/EHLO command was given followed by 500 or so spaces. As
    initially expressed, the concern was not well-founded, because trailing
    spaces are removed early. However, if the trailing spaces were followed by
    a NULL, they did not get removed, so the overflow was possible. Two fixes
    were applied:

    (a) I re-wrote the offending code in a cleaner fashion.
    (b) If an incoming SMTP command contains a NULL character, it is rejected
        as invalid.

82. When Exim changes uid/gid to the Exim user at daemon start time, it now
    runs initgroups(), so that if the Exim user is in any additional groups,
    they will be used during message reception.


Exim version 4.20
-----------------

The change log for 4.20 and earlier releases has been archived.

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