+Exim version 4.93
+-----------------
+
+For a detailed list of changes that might affect Exim's operation with
+an unchanged configuration, please see the doc/ChangeLog file.
+
+Build:
+
+ * SUPPORT_DMARC replaces EXPERIMENTAL_DMARC
+
+ * DISABLE_TLS replaces SUPPORT_TLS
+
+ * Bump the version for the local_scan API.
+
+Runtime:
+
+ * smtp transport option hosts_try_fastopen defaults to "*".
+
+ * DNSSec is requested (not required) for all queries. (This seemes to
+ ask for trouble if your resolver is a systemd-resolved.)
+
+ * Generic router option retry_use_local_part defaults to "true" under specific
+ pre-conditions.
+
+ * Introduce a tainting mechanism for values read from untrusted sources.
+
+ * Use longer file names for temporary spool files (this avoids
+ name conflicts with spool on a shared file system).
+
+ * Use dsn_from main config option (was ignored previously).
+
+
+Exim version 4.92
+-----------------
+
+ * Exim used to manually follow CNAME chains, to a limited depth. In this
+ day-and-age we expect the resolver to be doing this for us, so the loop
+ is limited to one retry unless the (new) config option dns_cname_loops
+ is changed.
+
+Exim version 4.91
+-----------------
+
+ * DANE and SPF have been promoted from Experimental to Supported status, thus
+ the options to enable them in Local/Makefile have been renamed.
+ See current src/EDITME for full details, including changes in dependencies,
+ but loosely: replace EXPERIMENTAL_SPF with SUPPORT_SPF and replace
+ EXPERIMENTAL_DANE with SUPPORT_DANE.
+
+ * Ancient ClamAV stream support, long deprecated by ClamAV, has been removed;
+ if you were building with WITH_OLD_CLAMAV_STREAM enabled then your problems
+ have marginally increased.
+
+ * A number of logging changes; if relying upon the previous DKIM additional
+ log-line, explicit log_selector configuration is needed to keep it.
+
+ * Other incompatible changes in EXPERIMENTAL_* features, read NewStuff and
+ ChangeLog carefully if relying upon an experimental feature such as DMARC.
+ Note that this includes changes to SPF as it was promoted into Supported.
+
+
+Exim version 4.89
+-----------------
+
+ * SMTP CHUNKING in Exim 4.88 did not ensure that received mails had a final
+ newline; attempts to deliver such messages onwards to non-chunking hosts
+ would probably hang, as Exim does not insert the newline before a ".".
+ In 4.89, the newline is added upon receipt. For already-received messages
+ in your queue, try util/chunking_fixqueue_finalnewlines.pl
+ to walk the queue, fixing any affected messages. Note that because a
+ delivery attempt will be hanging, attempts to lock the messages for fixing
+ them will stall; stopping all queue-runners temporarily is recommended.
+
+ * OpenSSL: oldest supported release series is now 1.0.2, which is the oldest
+ supported by the OpenSSL project. If you can build Exim with an older
+ release series, congratulations. If you can't, then upgrade.
+ The file doc/openssl.txt contains instructions for installing a current
+ OpenSSL outside the system library paths and building Exim to use it.
+
+ * FreeBSD: we now always use the system iconv in libc, as all versions of
+ FreeBSD supported by the FreeBSD project provide this functionality.
+
+
+Exim version 4.88
+-----------------
+
+ * The "demime" ACL condition, deprecated for the past 10 years, has
+ now been removed.
+
+ * Old GnuTLS configuration options "gnutls_require_kx", "gnutls_require_mac",
+ and "gnutls_require_protocols" have now been removed. (Inoperative from
+ 4.80, per below; logging warnings since 4.83, again per below).
+
+
+Exim version 4.83
+-----------------
+
+ * SPF condition results renamed "permerror" and "temperror". The old
+ names are still accepted for back-compatibility, for this release.
+
+ * TLS details are now logged on rejects, subject to log selectors.
+
+ * Items in headers_remove lists must now have any embedded list-separators
+ doubled.
+
+ * Attempted use of the deprecated options "gnutls_require_kx" et. al.
+ now result in logged warning.
+
+
+Exim version 4.82
+-----------------
+
+ * New option gnutls_allow_auto_pkcs11 defaults false; if you have GnuTLS 2.12.0
+ or later and do want PKCS11 modules to be autoloaded, then set this option.
+
+ * A per-transport wait-<name> database is no longer updated if the transport
+ sets "connection_max_messages" to 1, as it can not be used and causes
+ unnecessary serialisation and load. External tools tracking the state of
+ Exim by the hints databases may need modification to take this into account.
+
+ * The av_scanner option can now accept multiple clamd TCP targets, all other
+ setting limitations remain.
+
+
+Exim version 4.80
+-----------------
+
+ * BEWARE backwards-incompatible changes in SSL libraries, thus the version
+ bump. See points below for details.
+ Also an LDAP data returned format change.
+
+ * The value of $tls_peerdn is now print-escaped when written to the spool file
+ in a -tls_peerdn line, and unescaped when read back in. We received reports
+ of values with embedded newlines, which caused spool file corruption.
+
+ If you have a corrupt spool file and you wish to recover the contents after
+ upgrading, then lock the message, replace the new-lines that should be part
+ of the -tls_peerdn line with the two-character sequence \n and then unlock
+ the message. No tool has been provided as we believe this is a rare
+ occurrence.
+
+ * For OpenSSL, SSLv2 is now disabled by default. (GnuTLS does not support
+ SSLv2). RFC 6176 prohibits SSLv2 and some informal surveys suggest no
+ actual usage. You can re-enable with the "openssl_options" Exim option,
+ in the main configuration section. Note that supporting SSLv2 exposes
+ you to ciphersuite downgrade attacks.
+
+ * With OpenSSL 1.0.1+, Exim now supports TLS 1.1 and TLS 1.2. If built
+ against 1.0.1a then you will get a warning message and the
+ "openssl_options" value will not parse "no_tlsv1_1": the value changes
+ incompatibly between 1.0.1a and 1.0.1b, because the value chosen for 1.0.1a
+ is infelicitous. We advise avoiding 1.0.1a.
+
+ "openssl_options" gains "no_tlsv1_1", "no_tlsv1_2" and "no_compression".
+
+ COMPATIBILITY WARNING: The default value of "openssl_options" is no longer
+ "+dont_insert_empty_fragments". We default to "+no_sslv2".
+ That old default was grandfathered in from before openssl_options became a
+ configuration option.
+ Empty fragments are inserted by default through TLS1.0, to partially defend
+ against certain attacks; TLS1.1+ change the protocol so that this is not
+ needed. The DIEF SSL option was required for some old releases of mail
+ clients which did not gracefully handle the empty fragments, and was
+ initially set in Exim release 4.31 (see ChangeLog, item 37).
+
+ If you still have affected mail-clients, and you see SSL protocol failures
+ with this release of Exim, set:
+ openssl_options = +dont_insert_empty_fragments
+ in the main section of your Exim configuration file. You're trading off
+ security for compatibility. Exim is now defaulting to higher security and
+ rewarding more modern clients.
+
+ If the option tls_dhparams is set and the parameters loaded from the file
+ have a bit-count greater than the new option tls_dh_max_bits, then the file
+ will now be ignored. If this affects you, raise the tls_dh_max_bits limit.
+ We suspect that most folks are using dated defaults and will not be affected.
+
+ * Ldap lookups returning multi-valued attributes now separate the attributes
+ with only a comma, not a comma-space sequence. Also, an actual comma within
+ a returned attribute is doubled. This makes it possible to parse the
+ attribute as a comma-separated list. Note the distinction from multiple
+ attributes being returned, where each one is a name=value pair.
+
+ If you are currently splitting the results from LDAP upon a comma, then you
+ should check carefully to see if adjustments are needed.
+
+ This change lets cautious folks distinguish "comma used as separator for
+ joining values" from "comma inside the data".
+
+ * accept_8bitmime now defaults on, which is not RFC compliant but is better
+ suited to today's Internet. See http://cr.yp.to/smtp/8bitmime.html for a
+ sane rationale. Those who wish to be strictly RFC compliant, or know that
+ they need to talk to servers that are not 8-bit-clean, now need to take
+ explicit configuration action to default this option off. This is not a
+ new option, you can safely force it off before upgrading, to decouple
+ configuration changes from the binary upgrade while remaining RFC compliant.
+
+ * The GnuTLS support has been mostly rewritten, to use APIs which don't cause
+ deprecation warnings in GnuTLS 2.12.x. As part of this, these three options
+ are no longer supported:
+
+ gnutls_require_kx
+ gnutls_require_mac
+ gnutls_require_protocols
+
+ Their functionality is entirely subsumed into tls_require_ciphers. In turn,
+ tls_require_ciphers is no longer an Exim list and is not parsed by Exim, but
+ is instead given to gnutls_priority_init(3), which expects a priority string;
+ this behaviour is much closer to the OpenSSL behaviour. See:
+
+ http://www.gnutls.org/manual/html_node/Priority-Strings.html
+
+ for fuller documentation of the strings parsed. The three gnutls_require_*
+ options are still parsed by Exim and, for this release, silently ignored.
+ A future release will add warnings, before a later still release removes
+ parsing entirely and the presence of the options will be a configuration
+ error.
+
+ Note that by default, GnuTLS will not accept RSA-MD5 signatures in chains.
+ A tls_require_ciphers value of NORMAL:%VERIFY_ALLOW_SIGN_RSA_MD5 may
+ re-enable support, but this is not supported by the Exim maintainers.
+ Our test suite no longer includes MD5-based certificates.
+
+ This rewrite means that Exim will continue to build against GnuTLS in the
+ future, brings Exim closer to other GnuTLS applications and lets us add
+ support for SNI and other features more readily. We regret that it wasn't
+ feasible to retain the three dropped options.
+
+ * If built with TLS support, then Exim will now validate the value of
+ the main section tls_require_ciphers option at start-up. Before, this
+ would cause a STARTTLS 4xx failure, now it causes a failure to start.
+ Running with a broken configuration which causes failures that may only
+ be left in the logs has been traded off for something more visible. This
+ change makes an existing problem more prominent, but we do not believe
+ anyone would deliberately be running with an invalid tls_require_ciphers
+ option.
+
+ This also means that library linkage issues caused by conflicts of some
+ kind might take out the main daemon, not just the delivery or receiving
+ process. Conceivably some folks might prefer to continue delivering
+ mail plaintext when their binary is broken in this way, if there is a
+ server that is a candidate to receive such mails that does not advertise
+ STARTTLS. Note that Exim is typically a setuid root binary and given
+ broken linkage problems that cause segfaults, we feel it is safer to
+ fail completely. (The check is not done as root, to ensure that problems
+ here are not made worse by the check).
+
+ * The "tls_dhparam" option has been updated, so that it can now specify a
+ path or an identifier for a standard DH prime from one of a few RFCs.
+ The default for OpenSSL is no longer to not use DH but instead to use
+ one of these standard primes. The default for GnuTLS is no longer to use
+ a file in the spool directory, but to use that same standard prime.
+ The option is now used by GnuTLS too. If it points to a path, then
+ GnuTLS will use that path, instead of a file in the spool directory;
+ GnuTLS will attempt to create it if it does not exist.
+
+ To preserve the previous behaviour of generating files in the spool
+ directory, set "tls_dhparam = historic". Since prior releases of Exim
+ ignored tls_dhparam when using GnuTLS, this can safely be done before
+ the upgrade.
+
+
+
+Exim version 4.77
+-----------------
+
+ * GnuTLS will now attempt to use TLS 1.2 and TLS 1.1 before TLS 1.0 and SSL3,
+ if supported by your GnuTLS library. Use the existing
+ "gnutls_require_protocols" option to downgrade this if that will be a
+ problem. Prior to this release, supported values were "TLS1" and "SSL3",
+ so you should be able to update configuration prior to update.
+
+ [nb: gnutls_require_protocols removed in Exim 4.80, instead use
+ tls_require_ciphers to provide a priority string; see notes above]
+
+ * The match_<type>{string1}{string2} expansion conditions no longer subject
+ string2 to string expansion, unless Exim was built with the new
+ "EXPAND_LISTMATCH_RHS" option. Too many people have inadvertently created
+ insecure configurations that way. If you need the functionality and turn on
+ that build option, please let the developers know, and know why, so we can
+ try to provide a safer mechanism for you.
+
+ The match{}{} expansion condition (for regular expressions) is NOT affected.
+ For match_<type>{s1}{s2}, all list functionality is unchanged. The only
+ change is that a '$' appearing in s2 will not trigger expansion, but instead
+ will be treated as a literal $ sign; the effect is very similar to having
+ wrapped s2 with \N...\N. If s2 contains a named list and the list definition
+ uses $expansions then those _will_ be processed as normal. It is only the
+ point at which s2 is read where expansion is inhibited.
+
+ If you are trying to test if two email addresses are equal, use eqi{s1}{s2}.
+ If you are testing if the address in s1 occurs in the list of items given
+ in s2, either use the new inlisti{s1}{s2} condition (added in 4.77) or use
+ the pre-existing forany{s2}{eqi{$item}{s1}} condition.
+
+
+Exim version 4.74
+-----------------
+
+ * The integrated support for dynamically loadable lookup modules has an ABI
+ change from the modules supported by some OS vendors through an unofficial
+ patch. Don't try to mix & match.
+
+ * Some parts of the build system are now beginning to assume that the host
+ environment is POSIX. If you're building on a system where POSIX tools are
+ not the default, you might have an easier time if you switch to the POSIX
+ tools. Feel free to report non-POSIX issues as a request for a feature
+ enhancement, but if the POSIX variants are available then the fix will
+ probably just involve some coercion. See the README instructions for
+ building on such hosts.
+
+
+Exim version 4.73
+-----------------
+
+ * The Exim run-time user can no longer be root; this was always
+ strongly discouraged, but is now prohibited both at build and
+ run-time. If you need Exim to run routinely as root, you'll need to
+ patch the source and accept the risk. Here be dragons.
+
+ * Exim will no longer accept a configuration file owned by the Exim
+ run-time user, unless that account is explicitly the value in
+ CONFIGURE_OWNER, which we discourage. Exim now checks to ensure that
+ files are not writeable by other accounts.
+
+ * The ALT_CONFIG_ROOT_ONLY build option is no longer optional and is forced
+ on; the Exim user can, by default, no longer use -C/-D and retain privilege.
+ Two new build options mitigate this.
+
+ * TRUSTED_CONFIG_LIST defines a file containing a whitelist of config
+ files that are trusted to be selected by the Exim user; one per line.
+ This is the recommended approach going forward.
+
+ * WHITELIST_D_MACROS defines a colon-separated list of macro names which
+ the Exim run-time user may safely pass without dropping privileges.
+ Because changes to this involve a recompile, this is not the recommended
+ approach but may ease transition. The values of the macros, when
+ overridden, are constrained to match this regex: ^[A-Za-z0-9_/.-]*$
+
+ * The system_filter_user option now defaults to the Exim run-time user,
+ rather than root. You can still set it explicitly to root and this
+ can be done with prior versions too, letting you roll versions
+ without needing to change this configuration option.
+
+ * ClamAV must be at least version 0.95 unless WITH_OLD_CLAMAV_STREAM is
+ defined at build time.
+
+
+Exim version 4.70
+-----------------
+
+1. Experimental Yahoo! Domainkeys support has been dropped in this release.
+It has been superseded by a native implementation of its successor DKIM.
+
+2. Up to version 4.69, Exim came with an embedded version of the PCRE library.
+As of 4.70, this is no longer the case. To compile Exim, you will need PCRE
+installed. Most OS distributions have ready-made library and development
+packages.
+
+
+Exim version 4.68
+-----------------
+
+1. The internal implementation of the database keys that are used for ACL
+ratelimiting has been tidied up. This means that an update to 4.68 might cause
+Exim to "forget" previous rates that it had calculated, and reset them to zero.
+
+
+Exim version 4.64
+-----------------
+
+1. 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. This change is mentioned here in
+case somebody is relying on the use of $smtp_active_hostname.
+
+2. A bug has been fixed that might just possibly be something that is relied on
+in some configurations. In expansion items such as ${if >{xxx}{yyy}...} an
+empty string (that is {}) was being interpreted as if it was {0} and therefore
+treated as the number zero. From release 4.64, such strings cause an error
+because a decimal number, possibly followed by K or M, is required (as has
+always been documented).
+
+3. There has been a change to the GnuTLS support (ChangeLog/PH/20) to improve
+Exim's performance. Unfortunately, this has the side effect of being slightly
+non-upwards compatible for versions 4.50 and earlier. If you are upgrading from
+one of these earlier versions and you use GnuTLS, you must remove the file
+called gnutls-params in Exim's spool directory. If you don't do this, you will
+see this error:
+
+ TLS error on connection from ... (DH params import): Base64 decoding error.
+
+Removing the file causes Exim to recompute the relevant encryption parameters
+and cache them in the new format that was introduced for release 4.51 (May
+2005). If you are upgrading from release 4.51 or later, there should be no
+problem.
+