-$Cambridge: exim/doc/doc-txt/NewStuff,v 1.23 2004/12/22 12:05:45 ph10 Exp $
-
New Features in Exim
--------------------
-This file contains descriptions of new features that have been added to Exim,
-but have not yet made it into the main manual (which is most conveniently
-updated when there is a relatively large batch of changes). The doc/ChangeLog
-file contains a listing of all changes, including bug fixes.
+This file contains descriptions of new features that have been added to Exim.
+Before a formal release, there may be quite a lot of detail so that people can
+test from the snapshots or the CVS before the documentation is updated. Once
+the documentation is updated, this file is reduced to a short list.
+
+Version 4.83
+------------
+
+ 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
+ configured to expect an initial header from a proxy that will make the
+ actual external source IP:host be used in exim instead of the IP of the
+ proxy that is connecting to it.
+
+ 2. New verify option header_names_ascii, which will check to make sure
+ there are no non-ASCII characters in header names. Exim itself handles
+ those non-ASCII characters, but downstream apps may not, so Exim can
+ detect and reject if those characters are present.
+
+ 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
+ codepoints with valid ones.
+
+ 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
+ command line and matching a regex against the return data for trigger
+ and a second regex to extract malware_name. The mail spoofile name can
+ be included in the command line.
+ 5. The smtp transport now supports options "tls_verify_hosts" and
+ "tls_try_verify_hosts". If either is set the certificate verification
+ is split from the encryption operation. The default remains that a failed
+ verification cancels the encryption.
-Version 4.50
+ 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
+ lookup can now set a list of servers to use that is different from the
+ default list.
+
+
+Version 4.82
------------
- 1. There is a new build-time option called CONFIGURE_GROUP which works like
- CONFIGURE_OWNER. It specifies one additional group that is permitted for
- the runtime configuration file when the group write permission is set.
+ 1. New command-line option -bI:sieve will list all supported sieve extensions
+ of this Exim build on standard output, one per line.
+ ManageSieve (RFC 5804) providers managing scripts for use by Exim should
+ query this to establish the correct list to include in the protocol's
+ SIEVE capability line.
+
+ 2. If the -n option is combined with the -bP option, then the name of an
+ emitted option is not output, only the value (if visible to you).
+ For instance, "exim -n -bP pid_file_path" should just emit a pathname
+ followed by a newline, and no other text.
+
+ 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
+ has a "tls_dh_min_bits" option, to set the minimum acceptable number of
+ bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
+ acceptable for security. (Option accepted but ignored if using OpenSSL).
+ Defaults to 1024, the old value. May be lowered only to 512, or raised as
+ far as you like. Raising this may hinder TLS interoperability with other
+ sites and is not currently recommended. Lowering this will permit you to
+ establish a TLS session which is not as secure as you might like.
+
+ Unless you really know what you are doing, leave it alone.
+
+ 4. If not built with DISABLE_DNSSEC, Exim now has the main option
+ dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
+ to send the DO flag to your recursive resolver. If you have a recursive
+ resolver, which can set the Authenticated Data (AD) flag in results, Exim
+ can now detect this. Exim does not perform validation itself, instead
+ relying upon a trusted path to the resolver.
+
+ Current status: work-in-progress; $sender_host_dnssec variable added.
+
+ 5. DSCP support for outbound connections: on a transport using the smtp driver,
+ set "dscp = ef", for instance, to cause the connections to have the relevant
+ DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
+
+ Similarly for inbound connections, there is a new control modifier, dscp,
+ so "warn control = dscp/ef" in the connect ACL, or after authentication.
+
+ Supported values depend upon system libraries. "exim -bI:dscp" to list the
+ ones Exim knows of. You can also set a raw number 0..0x3F.
+
+ 6. The -G command-line flag is no longer ignored; it is now equivalent to an
+ ACL setting "control = suppress_local_fixups". The -L command-line flag
+ is now accepted and forces use of syslog, with the provided tag as the
+ process name. A few other flags used by Sendmail are now accepted and
+ ignored.
+
+ 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
+ ACL modifier; works for single-recipient mails which are recieved on and
+ deliverable via SMTP. Using the connection made for a recipient verify,
+ if requested before the verify, or a new one made for the purpose while
+ the inbound connection is still active. The bulk of the mail item is copied
+ direct from the inbound socket to the outbound (as well as the spool file).
+ When the source notifies the end of data, the data acceptance by the destination
+ is negociated before the acceptance is sent to the source. If the destination
+ does not accept the mail item, for example due to content-scanning, the item
+ is not accepted from the source and therefore there is no need to generate
+ a bounce mail. This is of benefit when providing a secondary-MX service.
+ The downside is that delays are under the control of the ultimate destination
+ system not your own.
+
+ The Recieved-by: header on items delivered by cutthrough is generated
+ early in reception rather than at the end; this will affect any timestamp
+ included. The log line showing delivery is recorded before that showing
+ reception; it uses a new ">>" tag instead of "=>".
+
+ To support the feature, verify-callout connections can now use ESMTP and TLS.
+ The usual smtp transport options are honoured, plus a (new, default everything)
+ hosts_verify_avoid_tls.
+
+ New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
+ for specific access to the information for each connection. The old names
+ are present for now but deprecated.
+
+ Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
+
+ 8. New expansion operators ${listnamed:name} to get the content of a named list
+ and ${listcount:string} to count the items in a list.
+
+ 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
+ rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
+ modules. For some situations this is desirable, but we expect admin in
+ those situations to know they want the feature. More commonly, it means
+ that GUI user modules get loaded and are broken by the setuid Exim being
+ unable to access files specified in environment variables and passed
+ through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
+ unless this new option is set.
+
+ Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
+ so have also added a build option which can be used to build Exim with GnuTLS
+ but without trying to use any kind of PKCS11 support. Uncomment this in the
+ Local/Makefile:
+
+ AVOID_GNUTLS_PKCS11=yes
+
+10. The "acl = name" condition on an ACL now supports optional arguments.
+ New expansion item "${acl {name}{arg}...}" and expansion condition
+ "acl {{name}{arg}...}" are added. In all cases up to nine arguments
+ can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
+ Variable $acl_narg contains the number of arguments. If the ACL sets
+ a "message =" value this becomes the result of the expansion item,
+ or the value of $value for the expansion condition. If the ACL returns
+ accept the expansion condition is true; if reject, false. A defer
+ return results in a forced fail.
+
+11. Routers and transports can now have multiple headers_add and headers_remove
+ option lines. The concatenated list is used.
+
+12. New ACL modifier "remove_header" can remove headers before message gets
+ handled by routers/transports.
+
+13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
+ "aaaa" and "a" lookups is done and the full set of results returned.
+
+14. New expansion variable $headers_added with content from ACL add_header
+ modifier (but not yet added to messsage).
+
+15. New 8bitmime status logging option for received messages. Log field "M8S".
+
+16. New authenticated_sender logging option, adding to log field "A".
+
+17. New expansion variables $router_name and $transport_name. Useful
+ particularly for debug_print as -bt commandline option does not
+ require privilege whereas -d does.
+
+18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
+ proposed extension to SMTP from Eric Hall.
+
+19. The pipe transport has gained the force_command option, to allow
+ decorating commands from user .forward pipe aliases with prefix
+ wrappers, for instance.
+
+20. Callout connections can now AUTH; the same controls as normal delivery
+ connections apply.
- 2. The "control=submission" facility has a new option /sender_retain. This
- has the effect of setting local_sender_retain true and local_from_check
- false for the incoming message in which it is encountered.
+21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
+ options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
+ It adds new expansion variables $dmarc_ar_header, $dmarc_status,
+ $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
+ dmarc_status. It adds new control flags dmarc_disable_verify and
+ dmarc_enable_forensic.
+
+22. Add expansion variable $authenticated_fail_id, which is the username
+ provided to the authentication method which failed. It is available
+ for use in subsequent ACL processing (typically quit or notquit ACLs).
- 3. $recipients is now available in the predata ACL (oversight).
+23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
+ UDP host and port.
- 4. The value of address_data from a sender verification is now available in
- $sender_address_data in subsequent conditions in the ACL statement. Note:
- this is just like $address_data. The value does not persist after the end
- of the current ACL statement. If you want to preserve it, you can use one
- of the ACL variables.
+24. New ${hexquote:..string..} expansion operator converts non-printable
+ characters in the string to \xNN form.
- 5. The redirect router has two new options: forbid_sieve_filter and
- forbid_exim_filter. When filtering is enabled by allow_filter, these
- options control which type(s) of filtering are permitted. By default, both
- Exim and Sieve filters are allowed.
+25. Experimental TPDA (Transport Post Delivery Action) function added.
+ Patch provided by Axel Rau.
- 6. A new option for callouts makes it possible to set a different (usually
- smaller) timeout for making the SMTP connection. The keyword is "connect".
- For example:
+26. Experimental Redis lookup added. Patch provided by Warren Baker.
- verify = sender/callout=5s,connect=1s
- If not specified, it defaults to the general timeout value.
+Version 4.80
+------------
+
+ 1. New authenticator driver, "gsasl". Server-only (at present).
+ This is a SASL interface, licensed under GPL, which can be found at
+ http://www.gnu.org/software/gsasl/.
+ This system does not provide sources of data for authentication, so
+ careful use needs to be made of the conditions in Exim.
+
+ 2. New authenticator driver, "heimdal_gssapi". Server-only.
+ A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
+ is no longer honoured for setuid programs by Heimdal. Use the
+ "server_keytab" option to point to the keytab.
+
+ 3. The "pkg-config" system can now be used when building Exim to reference
+ cflags and library information for lookups and authenticators, rather
+ than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
+ "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
+ without adjusting "TLS_INCLUDE" and "TLS_LIBS".
+
+ In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
+ find the headers and libraries for PCRE.
+
+ 4. New expansion variable $tls_bits.
+
+ 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
+ be joined together with ASCII NUL characters to construct the key to pass
+ into the DBM library. Can be used with gsasl to access sasldb2 files as
+ used by Cyrus SASL.
- 7. The new variables $sender_verify_failure and $recipient_verify_failure
- contain information about exactly what failed. In an ACL, after one of
- these failures, the relevant variable contains one of the following words:
+ 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
- qualify the address was unqualified (no domain), and the message
- was neither local nor came from an exempted host;
+ Avoid release 1.0.1a if you can. Note that the default value of
+ "openssl_options" is no longer "+dont_insert_empty_fragments", as that
+ increased susceptibility to attack. This may still have interoperability
+ implications for very old clients (see version 4.31 change 37) but
+ administrators can choose to make the trade-off themselves and restore
+ compatibility at the cost of session security.
- route routing failed;
+ 7. Use of the new expansion variable $tls_sni in the main configuration option
+ tls_certificate will cause Exim to re-expand the option, if the client
+ sends the TLS Server Name Indication extension, to permit choosing a
+ different certificate; tls_privatekey will also be re-expanded. You must
+ still set these options to expand to valid files when $tls_sni is not set.
- mail routing succeeded, and a callout was attempted; rejection
- occurred at or before the MAIL command (that is, on initial
- connection, HELO, or MAIL);
+ The SMTP Transport has gained the option tls_sni, which will set a hostname
+ for outbound TLS sessions, and set $tls_sni too.
- recipient the RCPT command in a callout was rejected;
+ A new log_selector, +tls_sni, has been added, to log received SNI values
+ for Exim as a server.
- postmaster the postmaster check in a callout was rejected.
+ 8. The existing "accept_8bitmime" option now defaults to true. This means
+ that Exim is deliberately not strictly RFC compliant. We're following
+ Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
+ Those who disagree, or know that they are talking to mail servers that,
+ even today, are not 8-bit clean, need to turn off this option.
- The main use of these variables is expected to be to distinguish between
- rejections of MAIL and rejections of RCPT.
+ 9. Exim can now be started with -bw (with an optional timeout, given as
+ -bw<timespec>). With this, stdin at startup is a socket that is
+ already listening for connections. This has a more modern name of
+ "socket activation", but forcing the activated socket to fd 0. We're
+ interested in adding more support for modern variants.
- 8. The command line option -dd behaves exactly like -d except when used on a
- command that starts a daemon process. In that case, debugging is turned off
- for the subprocesses that the daemon creates. Thus, it is useful for
- monitoring the behaviour of the daemon without creating as much output as
- full debugging.
+10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
+ for numbers indicates multiplication by 1024^3.
- 9. $host_address is now set to the target address during the checking of
- ignore_target_hosts.
+11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
+ gnutls_require_mac & gnutls_require_protocols are no longer supported.
+ tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
+ string, documentation for which is at:
+ http://www.gnutls.org/manual/html_node/Priority-Strings.html
-10. There are four new variables called $spool_space, $log_space,
- $spool_inodes, and $log_inodes. The first two contain the amount of free
- space in the disk partitions where Exim has its spool directory and log
- directory, respectively. (When these are in the same partition, the values
- will, of course, be the same.) The second two variables contain the numbers
- of free inodes in the respective partitions.
+ SNI support has been added to Exim's GnuTLS integration too.
- NOTE: Because disks can nowadays be very large, the values in the space
- variables are in kilobytes rather than in bytes. Thus, for example, to
- check in an ACL that there is at least 50M free on the spool, you would
- write:
+ For sufficiently recent GnuTLS libraries, ${randint:..} will now use
+ gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
- condition = ${if > {$spool_space}{50000}{yes}{no}}
+12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
+ is now available. If the contents of the file are valid, then Exim will
+ send that back in response to a TLS status request; this is OCSP Stapling.
+ Exim will not maintain the contents of the file in any way: administrators
+ are responsible for ensuring that it is up-to-date.
- The values are recalculated whenever any of these variables is referenced.
- If the relevant file system does not have the concept of inodes, the value
- of those variables is -1. If the operating system does not have the ability
- to find the amount of free space (only true for experimental systems), the
- space value is -1.
+ See "experimental-spec.txt" for more details.
-11. It is now permitted to omit both strings after an "if" condition; if the
- condition is true, the result is the string "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. For
- example, instead of
+13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
+ identically to TXT record lookups.
- condition = ${if eq {$acl_m4}{1}{yes}{no}}
+14. New expansion variable $tod_epoch_l for higher-precision time.
- or the shorter form
+15. New global option tls_dh_max_bits, defaulting to current value of NSS
+ hard-coded limit of DH ephemeral bits, to fix interop problems caused by
+ GnuTLS 2.12 library recommending a bit count higher than NSS supports.
- condition = ${if eq {$acl_m4}{1}{yes}}
+16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
+ Option can now be a path or an identifier for a standard prime.
+ If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
+ Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
+ primes.
- (because the second string has always defaulted to ""), you can now write
+17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
+ Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
+ install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
- condition = ${if eq {$acl_m4}{1}}
- Previously this was a syntax error.
+Version 4.77
+------------
-12. There is a new "record type" that can be specified in dnsdb lookups. It
- is "zns" (for "zone NS"). It performs a lookup for NS records on the given
- domain, but if none are found, it removes the first component of the domain
- name, and tries again. This process continues until NS records are found
- or there are no more components left (or there's a DNS error). In other
- words, it may return the name servers for a top-level domain, but it never
- returns the root name servers. If there are no NS records for the top-level
- domain, the lookup fails.
+ 1. New options for the ratelimit ACL condition: /count= and /unique=.
+ The /noupdate option has been replaced by a /readonly option.
- For example, ${lookup dnsdb{zns=xxx.quercite.com}} returns the name
- servers for quercite.com, whereas ${lookup dnsdb{zns=xxx.edu}} returns
- the name servers for edu, assuming in each case that there are no NS
- records for the full domain name.
+ 2. The SMTP transport's protocol option may now be set to "smtps", to
+ use SSL-on-connect outbound.
- You should be careful about how you use this lookup because, unless the
- top-level domain does not exist, the lookup will always return some host
- names. The sort of use to which this might be put is for seeing if the name
- servers for a given domain are on a blacklist. You can probably assume that
- the name servers for the high-level domains such as .com or .co.uk are not
- going to be on such a list.
+ 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
+ there is a problem talking to the AV scanner, or the AV scanner running.
-13. Another new "record type" is "mxh"; this looks up MX records just as "mx"
- does, but it returns only the names of the hosts, omitting the priority
- values.
+ 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
+ and check if the search item is a member of the list. This does not
+ support named lists, but does subject the list part to string expansion.
-14. It is now possible to specify a list of domains or IP addresses to be
- looked up in a dnsdb lookup. The list is specified in the normal Exim way,
- with colon as the default separator, but with the ability to change this.
- For example:
+ 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
+ built, Exim no longer performs string expansion on the second string of
+ the match_* expansion conditions: "match_address", "match_domain",
+ "match_ip" & "match_local_part". Named lists can still be used.
- ${lookup dnsdb{one.domain.com:two.domain.com}}
- ${lookup dnsdb{a=one.host.com:two.host.com}}
- ${lookup dnsdb{ptr = <; 1.2.3.4 ; 4.5.6.8}}
- In order to retain backwards compatibility, there is one special case: if
- the lookup type is PTR and no change of separator is specified, Exim looks
- to see if the rest of the string is precisely one IPv6 address. In this
- case, it does not treat it as a list.
+Version 4.76
+------------
- The data from each lookup is concatenated, with newline separators (by
- default - see 14 below), in the same way that multiple DNS records for a
- single item are handled.
+ 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
+ or off in the resolver library.
- The dnsdb lookup fails only if all the DNS lookups fail. If there is a
- temporary DNS error for any of them, the behaviour is controlled by
- an optional keyword followed by a comma that may appear before the record
- type. The possible keywords are "defer_strict", "defer_never", and
- "defer_lax". With "strict" behaviour, any temporary DNS error causes the
- whole lookup to defer. With "never" behaviour, a temporary DNS error is
- ignored, and the behaviour is as if the DNS lookup failed to find anything.
- With "lax" behaviour, all the queries are attempted, but a temporary DNS
- error causes the whole lookup to defer only if none of the other lookups
- succeed. The default is "lax", so the following lookups are equivalent:
- ${lookup dnsdb{defer_lax,a=one.host.com:two.host.com}}
- ${lookup dnsdb{a=one.host.com:two.host.com}}
+Version 4.75
+------------
- Thus, in the default case, as long as at least one of the DNS lookups
- yields some data, the dnsdb lookup succeeds.
+ 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
+ is now LDAP/TLS support, given sufficiently modern OpenLDAP client
+ libraries. The following global options have been added in support of
+ this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
+ ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
-15. It is now possible to specify the character to be used as a separator when
- a dnsdb lookup returns data from more than one DNS record. The default is a
- newline. To specify a different character, put '>' followed by the new
- character at the start of the query. For example:
+ 2. The pipe transport now takes a boolean option, "freeze_signal", default
+ false. When true, if the external delivery command exits on a signal then
+ Exim will freeze the message in the queue, instead of generating a bounce.
- ${lookup dnsdb{>: a=h1.test.ex:h2.test.ex}}
- ${lookup dnsdb{>| mxh=<;m1.test.ex;m2.test.ex}}
+ 3. Log filenames may now use %M as an escape, instead of %D (still available).
+ The %M pattern expands to yyyymm, providing month-level resolution.
- It is permitted to specify a space as the separator character. Note that
- more than one DNS record can be found for a single lookup item; this
- feature is relevant even when you do not specify a list.
+ 4. The $message_linecount variable is now updated for the maildir_tag option,
+ in the same way as $message_size, to reflect the real number of lines,
+ including any header additions or removals from transport.
- The same effect could be achieved by wrapping the lookup in ${tr...}; this
- feature is just a syntactic simplification.
+ 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
+ Exim now selects entries randomly, to better scale in a cluster setup.
-16. It is now possible to supply a list of domains and/or IP addresses to be
- lookup up in a DNS blacklist. Previously, only a single domain name could
- be given, for example:
- dnslists = black.list.tld/$sender_host_name
+Version 4.74
+------------
- What follows the slash can now be a list. As with all lists, the default
- separator is a colon. However, because this is a sublist within the list of
- DNS blacklist domains, it is necessary either to double the separators like
- this:
+ 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
+ the flaw permitted the Exim run-time user to cause root to append to
+ arbitrary files of the attacker's choosing, with the content based
+ on content supplied by the attacker.
- dnslists = black.list.tld/name.1::name.2
+ 2. Exim now supports loading some lookup types at run-time, using your
+ platform's dlopen() functionality. This has limited platform support
+ and the intention is not to support every variant, it's limited to
+ dlopen(). This permits the main Exim binary to not be linked against
+ all the libraries needed for all the lookup types.
- or to change the separator character, like this:
- dnslists = black.list.tld/<;name.1;name.2
+Version 4.73
+------------
+
+ NOTE: this version is not guaranteed backwards-compatible, please read the
+ items below carefully
+
+ 1. A new main configuration option, "openssl_options", is available if Exim
+ is built with SSL support provided by OpenSSL. The option allows
+ administrators to specify OpenSSL options to be used on connections;
+ typically this is to set bug compatibility features which the OpenSSL
+ developers have not enabled by default. There may be security
+ consequences for certain options, so these should not be changed
+ frivolously.
+
+ 2. A new pipe transport option, "permit_coredumps", may help with problem
+ diagnosis in some scenarios. Note that Exim is typically installed as
+ a setuid binary, which on most OSes will inhibit coredumps by default,
+ so that safety mechanism would have to be overridden for this option to
+ be able to take effect.
+
+ 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
+ Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
+ Note that this switches Exim to use a new API ("INSTREAM") and a future
+ release of ClamAV will remove support for the old API ("STREAM").
+
+ The av_scanner option, when set to "clamd", now takes an optional third
+ part, "local", which causes Exim to pass a filename to ClamAV instead of
+ the file content. This is the same behaviour as when clamd is pointed at
+ a Unix-domain socket. For example:
+
+ av_scanner = clamd:192.0.2.3 1234:local
+
+ ClamAV's ExtendedDetectionInfo response format is now handled.
+
+ 4. There is now a -bmalware option, restricted to admin users. This option
+ takes one parameter, a filename, and scans that file with Exim's
+ malware-scanning framework. This is intended purely as a debugging aid
+ to ensure that Exim's scanning is working, not to replace other tools.
+ Note that the ACL framework is not invoked, so if av_scanner references
+ ACL variables without a fallback then this will fail.
+
+ 5. There is a new expansion operator, "reverse_ip", which will reverse IP
+ addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
+
+ ${reverse_ip:192.0.2.4}
+ -> 4.2.0.192
+ ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
+ -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
+
+ 6. There is a new ACL control called "debug", to enable debug logging.
+ This allows selective logging of certain incoming transactions within
+ production environments, with some care. It takes two options, "tag"
+ and "opts"; "tag" is included in the filename of the log and "opts"
+ is used as per the -d<options> command-line option. Examples, which
+ don't all make sense in all contexts:
+
+ control = debug
+ control = debug/tag=.$sender_host_address
+ control = debug/opts=+expand+acl
+ control = debug/tag=.$message_exim_id/opts=+expand
+
+ 7. It has always been implicit in the design and the documentation that
+ "the Exim user" is not root. src/EDITME said that using root was
+ "very strongly discouraged". This is not enough to keep people from
+ shooting themselves in the foot in days when many don't configure Exim
+ themselves but via package build managers. The security consequences of
+ running various bits of network code are severe if there should be bugs in
+ them. As such, the Exim user may no longer be root. If configured
+ statically, Exim will refuse to build. If configured as ref:user then Exim
+ will exit shortly after start-up. If you must shoot yourself in the foot,
+ then henceforth you will have to maintain your own local patches to strip
+ the safeties off.
+
+ 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
+ condition logic to determine truth/failure and will fail to expand many
+ strings, bool_lax{} uses the router condition logic, where most strings
+ do evaluate true.
+ Note: bool{00} is false, bool_lax{00} is true.
+
+ 9. Routers now support multiple "condition" tests.
+
+10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
+ Setting this allows an admin to define which entry in the tcpwrappers
+ config file will be used to control access to the daemon. This option
+ is only available when Exim is built with USE_TCP_WRAPPERS. The
+ default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
+ build option.
+
+11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
+ the Exim run-time user, instead of root.
+
+12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
+ is forced on. This is mitigated by the new build option
+ TRUSTED_CONFIG_LIST which defines a list of configuration files which
+ are trusted; one per line. If a config file is owned by root and matches
+ a pathname in the list, then it may be invoked by the Exim build-time
+ user without Exim relinquishing root privileges.
+
+13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
+ trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
+ forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
+ include the main config. As a transition mechanism, we are temporarily
+ providing a work-around: the new build option WHITELIST_D_MACROS provides
+ a colon-separated list of macro names which may be overridden by the Exim
+ run-time user. The values of these macros are constrained to the regex
+ ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
+
+
+Version 4.72
+------------
- If an item in the list is an IP address, it is inverted before the DNS
- blacklist domain is appended. If it is not an IP address, no inversion
- occurs. Consider this condition:
+ 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
+ writable, the other to locking of MBX folders (not mbox).
- dnslists = black.list.tls/<;192.168.1.2;a.domain
+ 2. MySQL stored procedures are now supported.
- The DNS lookups that occur are for
+ 3. The dkim_domain transport option is now a list, not a single string, and
+ messages will be signed for each element in the list (discarding
+ duplicates).
- 2.1.168.192.black.list.tld and a.domain.black.list.tld
+ 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
+ in the presence of multiple character strings within the RR. Prior to 4.70,
+ only the first string would be returned. The dnsdb lookup now, by default,
+ preserves the pre-4.70 semantics, but also now takes an extended output
+ separator specification. The separator can be followed by a semicolon, to
+ concatenate the individual text strings together with no join character,
+ or by a comma and a second separator character, in which case the text
+ strings within a TXT record are joined on that second character.
+ Administrators are reminded that DNS provides no ordering guarantees
+ between multiple records in an RRset. For example:
- Once a DNS record has been found (that matches a specific IP return
- address, if specified), no further lookups are done. If there is a
- temporary DNS error, the rest of the sublist of domains or IP addresses is
- tried. The dnslists item itself defers only if none of the other DNS
- lookups in this sublist succeeds. In other words, a successful lookup for
- any of the items in the sublist overrides a defer for a previous item.
+ foo.example. IN TXT "a" "b" "c"
+ foo.example. IN TXT "d" "e" "f"
-17. The log selector queue_time_overall causes Exim to output the time spent on
- the queue as an addition to the "Completed" message. Like queue_time (which
- puts the queue time on individual delivery lines), the time is tagged with
- "QT=", and it is measured from the time that the message starts to be
- received, so it includes the reception time.
+ ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
+ ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
+ ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
-18. It is now possible to use both -bF and -bf on the same command, in order to
- test a system filter and a user filter in the same run. For example:
- exim -bF /system/filter -bf /user/filter </test/message
+Version 4.70 / 4.71
+-------------------
- This is helpful when the system filter adds header lines or sets filter
- variables that are used by the user filter.
+ 1. Native DKIM support without an external library.
+ (Note that if no action to prevent it is taken, a straight upgrade will
+ result in DKIM verification of all signed incoming emails. See spec
+ for details on conditionally disabling)
-19. The Exiscan patch is now merged into the main source. See src/EDITME for
- parameters for the build.
+ 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
-20. If the key for a dnsdb lookup is not an IP address, it is used verbatim,
- without component reversal and without the addition of in-addr.arpa or
- ip6.arpa.
+ 3. There is now a bool{} expansion condition which maps certain strings to
+ true/false condition values (most likely of use in conjunction with the
+ and{} expansion operator).
-21. Two changes related to the smtp_active_hostname option:
+ 4. The $spam_score, $spam_bar and $spam_report variables are now available
+ at delivery time.
- (1) $smtp_active_hostname is now available as a variable. Its value
- sticks with the message and is therefore available in routers and
- transports at delivery time.
+ 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
+ options, provided that Exim is invoked by an admin_user.
- (2) The default for smtp_banner uses $smtp_active_hostname instead
- of $primary_hostname.
+ 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
+ which increases compatibility with older clients at the cost of decreased
+ security. Don't set this unless you need to support such clients.
+ 7. There is a new expansion operator, ${randint:...} which will produce a
+ "random" number less than the supplied integer. This randomness is
+ not guaranteed to be cryptographically strong, but depending upon how
+ Exim was built may be better than the most naive schemes.
-Version 4.43
+ 8. Exim now explicitly ensures that SHA256 is available when linked against
+ OpenSSL.
+
+ 9. The transport_filter_timeout option now applies to SMTP transports too.
+
+
+Version 4.69
------------
- 1. There is a new Boolean global option called mua_wrapper, defaulting false.
- This causes Exim to run an a restricted mode, in order to provide a very
- specific service.
-
- Background: On a personal computer, it is a common requirement for all
- email to be sent to a smarthost. There are plenty of MUAs that can be
- configured to operate that way, for all the popular operating systems.
- However, there are MUAs for Unix-like systems that cannot be so configured:
- they submit messages using the command line interface of
- /usr/sbin/sendmail. In addition, utility programs such as cron submit
- messages this way.
-
- Requirement: The requirement is for something that can provide the
- /usr/sbin/sendmail interface and deliver messages to a smarthost, but not
- provide any queueing or retrying facilities. Furthermore, the delivery to
- the smarthost should be synchronous, so that if it fails, the sending MUA
- is immediately informed. In other words, we want something that in effect
- converts a command-line MUA into a TCP/SMTP MUA.
-
- Solutions: There are a number of applications (for example, ssmtp) that do
- this job. However, people have found them to be lacking in various ways.
- For instance, some sites want to allow aliasing and forwarding before
- sending to the smarthost.
-
- Using Exim: Exim already had the necessary infrastructure for doing this
- job. Just a few tweaks were needed to make it behave as required, though it
- is somewhat of an overkill to use a fully-featured MTA for this purpose.
-
- Setting mua_wrapper=true causes Exim to run in a special mode where it
- assumes that it is being used to "wrap" a command-line MUA in the manner
- just described.
-
- If you set mua_wrapper=true, you also need to provide a compatible router
- and transport configuration. Typically there will be just one router and
- one transport, sending everything to a smarthost.
-
- When run in MUA wrapping mode, the behaviour of Exim changes in the
- following ways:
-
- (a) A daemon cannot be run, nor will Exim accept incoming messages from
- inetd. In other words, the only way to submit messages is via the
- command line.
-
- (b) Each message is synchonously delivered as soon as it is received (-odi
- is assumed). All queueing options (queue_only, queue_smtp_domains,
- control=queue, control=freeze in an ACL etc.) are quietly ignored. The
- Exim reception process does not finish until the delivery attempt is
- complete. If the delivery was successful, a zero return code is given.
-
- (c) Address redirection is permitted, but the final routing for all
- addresses must be to the same remote transport, and to the same list of
- hosts. Furthermore, the return_address must be the same for all
- recipients, as must any added or deleted header lines. In other words,
- it must be possible to deliver the message in a single SMTP
- transaction, however many recipients there are.
-
- (d) If the conditions in (c) are not met, or if routing any address results
- in a failure or defer status, or if Exim is unable to deliver all the
- recipients successfully to one of the hosts immediately, delivery of
- the entire message fails.
-
- (e) Because no queueing is allowed, all failures are treated as permanent;
- there is no distinction between 4xx and 5xx SMTP response codes from
- the smarthost. Furthermore, because only a single yes/no response can
- be given to the caller, it is not possible to deliver to some
- recipients and not others. If there is an error (temporary or
- permanent) for any recipient, all are failed.
-
- (f) If more than one host is listed, Exim will try another host after a
- connection failure or a timeout, in the normal way. However, if this
- kind of failure happens for all the hosts, the delivery fails.
-
- (g) When delivery fails, an error message is written to the standard error
- stream (as well as to Exim's log), and Exim exits to the caller with a
- return code value 1. The message is expunged from Exim's spool files.
- No bounce messages are ever generated.
-
- (h) No retry data is maintained, and any retry rules are ignored.
-
- (i) A number of Exim options are overridden: deliver_drop_privilege is
- forced true, max_rcpt in the smtp transport is forced to "unlimited",
- remote_max_parallel is forced to one, and fallback hosts are ignored.
-
- The overall effect is that Exim makes a single synchronous attempt to
- deliver the message, failing if there is any kind of problem. Because no
- local deliveries are done and no daemon can be run, Exim does not need root
- privilege. It should be possible to run it setuid=exim instead of
- setuid=root. See section 48.3 in the 4.40 manual for a general discussion
- about the advantages and disadvantages of running without root privilege.
-
- 2. There have been problems with DNS servers when SRV records are looked up.
- Some mis-behaving servers return a DNS error or timeout when a non-existent
- SRV record is sought. Similar problems have in the past been reported for
- MX records. The global dns_again_means_nonexist option can help with this
- problem, but it is heavy-handed because it is a global option. There are
- now two new options for the dnslookup router. They are called
- srv_fail_domains and mx_fail_domains. In each case, the value is a domain
- list. If an attempt to look up an SRV or MX record results in a DNS failure
- or "try again" response, and the domain matches the relevant list, Exim
- behaves as if the DNS had responded "no such record". In the case of an SRV
- lookup, this means that the router proceeds to look for MX records; in the
- case of an MX lookup, it proceeds to look for A or AAAA records, unless the
- domain matches mx_domains.
-
- 3. The following functions are now available in the local_scan() API:
-
- (a) void header_remove(int occurrence, uschar *name)
-
- This function removes header lines. If "occurrence" is zero or negative,
- all occurrences of the header are removed. If occurrence is greater
- than zero, that particular instance of the header is removed. If no
- header(s) can be found that match the specification, the function does
- nothing.
-
- (b) BOOL header_testname(header_line *hdr, uschar *name, int length,
- BOOL notdel)
-
- This function tests whether the given header has the given name. It
- is not just a string comparison, because whitespace is permitted
- between the name and the colon. If the "notdel" argument is TRUE, a
- FALSE return is forced for all "deleted" headers; otherwise they are
- not treated specially. For example:
-
- if (header_testname(h, US"X-Spam", 6, TRUE)) ...
-
- (c) void header_add_at_position(BOOL after, uschar *name, BOOL topnot,
- int type, char *format, ...)
-
- This function adds a new header line at a specified point in the header
- chain. If "name" is NULL, the new header is added at the end of the
- chain if "after" is TRUE, or at the start if "after" is FALSE. If
- "name" is not NULL, the headers are searched for the first non-deleted
- header that matches the name. If one is found, the new header is added
- before it if "after" is FALSE. If "after" is true, the new header is
- added after the found header and any adjacent subsequent ones with the
- same name (even if marked "deleted"). If no matching non-deleted header
- is found, the "topnot" option controls where the header is added. If it
- is TRUE, addition is at the top; otherwise at the bottom. Thus, to add
- a header after all the Received: headers, or at the top if there are no
- Received: headers, you could use
-
- header_add_at_position(TRUE, US"Received", TRUE, ' ', "X-xxx: ...");
-
- Normally, there is always at least one non-deleted Received: header,
- but there may not be if received_header_text expands to an empty
- string.
-
- (d) BOOL receive_remove_recipient(uschar *recipient)
-
- This is a convenience function to remove a named recipient from the
- list of recipients. It returns TRUE if a recipient was removed, and
- FALSE if no matching recipient could be found. The argument must be a
- complete email address.
-
- 4. When an ACL "warn" statement adds one or more header lines to a message,
- they are added at the end of the existing header lines by default. It is
- now possible to specify that any particular header line should be added
- right at the start (before all the Received: lines) or immediately after
- the first block of Received: lines in the message. This is done by
- specifying :at_start: or :after_received: (or, for completeness, :at_end:)
- before the text of the header line. (Header text cannot start with a colon,
- as there has to be a header name first.) For example:
-
- warn message = :after_received:X-My-Header: something or other...
-
- If more than one header is supplied in a single warn statement, each one is
- treated independently and can therefore be placed differently. If you add
- more than one line at the start, or after the Received: block, they will
- end up in reverse order.
-
- Warning: This facility currently applies only to header lines that are
- added in an ACL. It does NOT work for header lines that are added in a
- system filter or in a router or transport.
-
- 5. There is now a new error code that can be used in retry rules. Its name is
- "rcpt_4xx", and there are three forms. A literal "rcpt_4xx" matches any 4xx
- error received for an outgoing SMTP RCPT command; alternatively, either the
- first or both of the x's can be given as digits, for example: "rcpt_45x" or
- "rcpt_436". If you want (say) to recognize 452 errors given to RCPT
- commands by a particular host, and have only a one-hour retry for them, you
- can set up a retry rule of this form:
-
- the.host.name rcpt_452 F,1h,10m
-
- Naturally, this rule must come before any others that would match.
-
- These new errors apply to both outgoing SMTP (the smtp transport) and
- outgoing LMTP (either the lmtp transport, or the smtp transport in LMTP
- mode). Note, however, that they apply only to responses to RCPT commands.
-
- 6. The "postmaster" option of the callout feature of address verification has
- been extended to make it possible to use a non-empty MAIL FROM address when
- checking a postmaster address. The new suboption is called "postmaster_
- mailfrom", and you use it like this:
-
- require verify = sender/callout=postmaster_mailfrom=abc@x.y.z
-
- Providing this suboption causes the postmaster check to be done using the
- given address. The original "postmaster" option is equivalent to
-
- require verify = sender/callout=postmaster_mailfrom=
-
- If both suboptions are present, the rightmost one overrides.
-
- Important notes:
-
- (1) If you use a non-empty sender address for postmaster checking, there is
- the likelihood that the remote host will itself initiate a callout
- check back to your host to check that address. As this is a "normal"
- callout check, the sender will most probably be empty, thus avoiding
- possible callout loops. However, to be on the safe side it would be
- best to set up your own ACLs so that they do not do sender verification
- checks when the recipient is the address you use for postmaster callout
- checking.
-
- (2) The caching arrangements for postmaster checking do NOT take account of
- the sender address. It is assumed that either the empty address, or a
- fixed non-empty address will be used. All that Exim remembers is that
- the postmaster check for the domain succeeded or failed.
-
- 7. When verifying addresses in header lines using the verify=header_sender
- option, Exim behaves by default as if the addresses are envelope sender
- addresses from a message. Callout verification therefore tests to see
- whether a bounce message could be delivered, by using an empty address in
- the MAIL FROM command. However, it is arguable that these addresses might
- never be used as envelope senders, and could therefore justifiably reject
- bounce messages (empty senders). There is now an additional callout option
- for verify=header_sender that allows you to specify what address to use in
- the MAIL FROM command. You use it as in this example:
-
- require verify = header_sender/callout=mailfrom=abcd@x.y.z
-
- Important notes:
-
- (1) As in the case of postmaster_mailfrom (see above), you should think
- about possible loops.
-
- (2) In this case, as in the case of recipient callouts with non-empty
- senders (the use_sender option), caching is done on the basis of a
- recipient/sender pair.
-
- 8. If you build Exim with USE_READLINE=yes in Local/Makefile, it will try to
- load libreadline dynamically whenever the -be (test expansion) option is
- used without command line arguments. If successful, it will then use
- readline() for reading the test data. A line history is supported. By the
- time Exim does this, it is running as the calling user, so this should not
- cause any security problems. Security is the reason why this is NOT
- supported for -bt or -bv, when Exim is running as root or exim,
- respectively. Note that this option adds to the size of the Exim binary,
- because the dynamic loading library is not otherwise included. On my
- desktop it adds about 2.5K. You may need to add -ldl to EXTRA_LIBS when you
- set USE_READLINE=yes.
-
- 9. Added ${str2b64:<string>} to the expansion operators. This operator
- converts an arbitrary string into one that is base64 encoded.
-
-10. A new authenticator, called cyrus_sasl, has been added. This requires
- the presence of the Cyrus SASL library; it authenticates by calling this
- library, which supports a number of authentication mechanisms, including
- PLAIN and LOGIN, but also several others that Exim does not support
- directly. The code for this authenticator was provided by Matthew
- Byng-Maddick of A L Digital Ltd (http://www.aldigital.co.uk). Here follows
- draft documentation:
-
- xx. THE CYRUS_SASL AUTHENTICATOR
-
- The cyrus_sasl authenticator provides server support for the Cyrus library
- Implementation of the RFC 2222 "Simple Authentication and Security Layer".
- It provides a gatewaying mechanism directly to the Cyrus interface, so if
- your Cyrus library can do, for example, CRAM-MD5, then so can the
- cyrus_sasl authenticator. By default it uses the public name of the driver
- to determine which mechanism to support.
-
- Where access to some kind of secret file is required, for example in GSSAPI
- or CRAM-MD5, it is worth noting that the authenticator runs as the exim
- user, and that the Cyrus SASL library has no way of escalating privileges
- by default. You may also find you need to set environment variables,
- depending on the driver you are using.
-
- xx.1 Using cyrus_sasl as a server
-
- The cyrus_sasl authenticator has four private options. It puts the username
- (on a successful authentication) into $1.
-
- server_hostname Type: string* Default: $primary_hostname
-
- This option selects the hostname that is used when communicating with
- the library. It is up to the underlying SASL plug-in what it does with
- this data.
-
- server_mech Type: string Default: public_name
-
- This option selects the authentication mechanism this driver should
- use. It allows you to use a different underlying mechanism from the
- advertised name. For example:
-
- sasl:
- driver = cyrus_sasl
- public_name = X-ANYTHING
- server_mech = CRAM-MD5
- server_set_id = $1
-
- server_realm Type: string Default: unset
-
- This is the SASL realm that the server is claiming to be in.
-
- server_service Type: string Default: "smtp"
-
- This is the SASL service that the server claims to implement.
-
- For straigthforward cases, you do not need to set any of the
- authenticator's private options. All you need to do is to specify an
- appropriate mechanism as the public name. Thus, if you have a SASL library
- that supports CRAM-MD5 and PLAIN, you might have two authenticators as
- follows:
-
- sasl_cram_md5:
- driver = cyrus_sasl
- public_name = CRAM-MD5
- server_set_id = $1
-
- sasl_plain:
- driver = cyrus_sasl
- public_name = PLAIN
- server_set_id = $1
-
-11. There is a new global option called tls_on_connect_ports. Its value must be
- a list of port numbers; the most common use is expected to be
-
- tls_on_connect_ports = 465
-
- Setting this option has the same effect as -tls-on-connect on the command
- line, but only for the specified ports. It applies to all connections, both
- via the daemon and via inetd. You still need to specify all the ports for
- the daemon (using daemon_smtp_ports or local_interfaces or the -X command
- line option) because this option does not add an extra port -- rather, it
- specifies different behaviour on a port that is defined elsewhere. The
- -tls-on-connect command line option overrides tls_on_connect_ports, and
- forces tls-on-connect for all ports.
-
-12. There is a new ACL that is run when a DATA command is received, before the
- data itself is received. The ACL is defined by acl_smtp_predata. (Compare
- acl_smtp_data, which is run after the data has been received.)
- This new ACL allows a negative response to be given to the DATA command
- itself. Header lines added by MAIL or RCPT ACLs are not visible at this
- time, but any that are defined here are visible when the acl_smtp_data ACL
- is run.
-
-13. The "control=submission" ACL modifier has an option "/domain=xxx" which
- specifies the domain to be used when creating From: or Sender: lines using
- the authenticated id as a local part. If the option is supplied with an
- empty domain, that is, just "/domain=", Exim assumes that the authenticated
- id is a complete email address, and it uses it as is when creating From:
- or Sender: lines.
-
-14. It is now possible to make retry rules that apply only when the failing
- message has a specific sender. In particular, this can be used to define
- retry rules that apply only to bounce messages. The syntax is to add a new
- third item to a retry rule, of the form "senders=<address list>". The retry
- timings themselves then become the fourth item. For example:
-
- * * senders=: F,1h,30m
-
- would match all bounce messages. If the address list contains white space,
- it must be enclosed in quotes. For example:
-
- a.domain timeout senders="x@b.dom : y@c.dom" G,8h,10m,1.5
-
- When testing retry rules using -brt, you can supply a sender using the -f
- command line option, like this:
-
- exim -f "" -brt user@dom.ain
-
- If you do not set -f with -brt, a retry rule that contains a senders list
- will never be matched.
-
-15. Two new control modifiers have been added to ACLs: "control = enforce_sync"
- and "control = no_enforce_sync". This makes it possible to be selective
- about when SMTP synchronization is enforced. The global option
- smtp_enforce_sync now specifies the default state of the switch. These
- controls can appear in any ACL, but the most obvious place to put them is
- in the ACL defined by acl_smtp_connect, which is run at the start of an
- incoming SMTP connection, before the first synchronization check.
-
-16. Another two new control modifiers are "control = caseful_local_part" and
- "control = caselower_local_part". These are permitted only in the ACL
- specified by acl_smtp_rcpt (i.e. during RCPT processing). By default, the
- contents of $local_part are lower cased before ACL processing.
- After "control = caseful_local_part", any uppercase letters in the original
- local part are restored in $local_part for the rest of the ACL, or until
- "control = caselower_local_part" is encountered. However, this applies only
- to local part handling that takes place directly in the ACL (for example,
- as a key in lookups). If a "verify = recipient" test is obeyed, the
- case-related handling of the local part during the verification is
- controlled by the router configuration (see the caseful_local_part generic
- router option).
-
- This facility could be used, for example, to add a spam score to local
- parts containing upper case letters. For example, using $acl_m4 to
- accumulate the spam score:
-
- warn control = caseful_local_part
- set acl_m4 = ${eval:\
- $acl_m4 + \
- ${if match{$local_part}{[A-Z]}{1}{0}}\
- }
- control = caselower_local_part
-
- Notice that we put back the lower cased version afterwards, assuming that
- is what is wanted for subsequent tests.
-
-17. The option hosts_connection_nolog is provided so that certain hosts can be
- excepted from logging when the +smtp_connection log selector is set. For
- example, you might want not to log SMTP connections from local processes,
- or from 127.0.0.1, or from your local LAN. The option is a host list with
- an unset default. Because it is consulted in the main loop of the daemon,
- you should strive to restrict its value to a short inline list of IP
- addresses and networks. To disable logging SMTP connections from local
- processes, you must create a host list with an empty item. For example:
-
- hosts_connection_nolog = :
-
- If the +smtp_connection log selector is not set, this option has no effect.
-
-18. There is now an acl called acl_smtp_quit, which is run for the QUIT
- command. The outcome of the ACL does not affect the response code to QUIT,
- which is always 221. Thus, the ACL does not in fact control any access.
- For this reason, the only verbs that are permitted are "accept" and "warn".
-
- The ACL can be used for tasks such as custom logging at the end of an SMTP
- session. For example, you can use ACL variables in other ACLs to count
- messages, recipients, etc., and log the totals at QUIT time using one or
- more "logwrite" modifiers on a "warn" command.
-
- You do not need to have a final "accept", but if you do, you can use a
- "message" modifier to specify custom text that is sent as part of the 221
- response.
-
- This ACL is run only for a "normal" QUIT. For certain kinds of disastrous
- failure (for example, failure to open a log file, or when Exim is bombing
- out because it has detected an unrecoverable error), all SMTP commands
- from the client are given temporary error responses until QUIT is received
- or the connection is closed. In these special cases, the ACL is not run.
-
-19. The appendfile transport has two new options, mailbox_size and mailbox_
- filecount. If either these options are set, it is expanded, and the result
- is taken as the current size of the mailbox or the number of files in the
- mailbox, respectively. This makes it possible to use some external means of
- maintaining the data about the size of a mailbox for enforcing quota
- limits. The result of expanding these option values must be a decimal
- number, optionally followed by "K" or "M".
-
-20. It seems that there are broken clients in use that cannot handle multiline
- SMTP responses. Can't people who implement these braindead programs read?
- RFC 821 mentions multiline responses, and it is over 20 years old. They
- must handle multiline responses for EHLO, or do they still use HELO?
- Anyway, here is YAWFAB (yet another workaround for asinine brokenness).
- There's a new ACL switch that can be set by
-
- control = no_multiline_responses
-
- If this is set, it suppresses multiline SMTP responses from ACL rejections.
- One way of doing this would have been just to put out these responses as
- one long line. However, RFC 2821 specifies a maximum of 512 bytes per
- response ("use multiline responses for more" it says), and some of the
- responses might get close to that. So I have implemented this by doing two
- very easy things:
-
- (1) Extra information that is normally output as part of a rejection
- caused by sender verification failure is omitted. Only the final line
- (typically "sender verification failed") is now sent.
-
- (2) If a "message" modifier supplies a multiline response, only the first
- line is output.
-
- The setting of the switch can, of course, be made conditional on the
- calling host.
-
-21. There is now support for the libradius library that comes with FreeBSD.
- This is an alternative to the radiusclient library that Exim already
- supports. To use the FreeBSD library, you need to set
-
- RADIUS_LIB_TYPE=RADLIB
-
- in Local/Makefile, in addition to RADIUS_CONFIGURE_FILE, and you probably
- also need -libradius in EXTRALIBS.
-
-
-Version 4.42
+ 1. Preliminary DKIM support in Experimental.
+
+
+Version 4.68
------------
- 1. The "personal" filter test is brought up-to-date with recommendations from
- the Sieve specification: (a) The list of non-personal From: addresses now
- includes "listserv", "majordomo", and "*-request"; (b) If the message
- contains any header line starting with "List=-" it is treated as
- non-personal.
+ 1. The body_linecount and body_zerocount C variables are now exported in the
+ local_scan API.
+
+ 2. When a dnslists lookup succeeds, the key that was looked up is now placed
+ in $dnslist_matched. When the key is an IP address, it is not reversed in
+ this variable (though it is, of course, in the actual lookup). In simple
+ cases, for example:
+
+ deny dnslists = spamhaus.example
+
+ the key is also available in another variable (in this case,
+ $sender_host_address). In more complicated cases, however, this is not
+ true. For example, using a data lookup might generate a dnslists lookup
+ like this:
+
+ deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
+
+ If this condition succeeds, the value in $dnslist_matched might be
+ 192.168.6.7 (for example).
+
+ 3. Authenticators now have a client_condition option. When Exim is running as
+ a client, it skips an authenticator whose client_condition expansion yields
+ "0", "no", or "false". This can be used, for example, to skip plain text
+ authenticators when the connection is not encrypted by a setting such as:
+
+ client_condition = ${if !eq{$tls_cipher}{}}
+
+ Note that the 4.67 documentation states that $tls_cipher contains the
+ cipher used for incoming messages. In fact, during SMTP delivery, it
+ contains the cipher used for the delivery. The same is true for
+ $tls_peerdn.
+
+ 4. There is now a -Mvc <message-id> option, which outputs a copy of the
+ message to the standard output, in RFC 2822 format. The option can be used
+ only by an admin user.
+
+ 5. There is now a /noupdate option for the ratelimit ACL condition. It
+ computes the rate and checks the limit as normal, but it does not update
+ the saved data. This means that, in relevant ACLs, it is possible to lookup
+ the existence of a specified (or auto-generated) ratelimit key without
+ incrementing the ratelimit counter for that key.
+
+ In order for this to be useful, another ACL entry must set the rate
+ for the same key somewhere (otherwise it will always be zero).
+
+ Example:
+
+ acl_check_connect:
+ # Read the rate; if it doesn't exist or is below the maximum
+ # we update it below
+ deny ratelimit = 100 / 5m / strict / noupdate
+ log_message = RATE: $sender_rate / $sender_rate_period \
+ (max $sender_rate_limit)
+
+ [... some other logic and tests...]
+
+ warn ratelimit = 100 / 5m / strict / per_cmd
+ log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
+ (max $sender_rate_limit)
+ condition = ${if le{$sender_rate}{$sender_rate_limit}}
+
+ accept
+
+ 6. The variable $max_received_linelength contains the number of bytes in the
+ longest line that was received as part of the message, not counting the
+ line termination character(s).
- 2. The Sieve functionality has been extended to support the "copy" and
- "vacation" extensions, and comparison tests.
+ 7. Host lists can now include +ignore_defer and +include_defer, analagous to
+ +ignore_unknown and +include_unknown. These options should be used with
+ care, probably only in non-critical host lists such as whitelists.
- 3. 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:
+ 8. There's a new option called queue_only_load_latch, which defaults true.
+ If set false when queue_only_load is greater than zero, Exim re-evaluates
+ the load for each incoming message in an SMTP session. Otherwise, once one
+ message is queued, the remainder are also.
- verify = sender/callout=5s,maxwait=20s
+ 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
+ cases when an SMTP session ends without sending QUIT. However, when Exim
+ itself is is bad trouble, such as being unable to write to its log files,
+ this ACL is not run, because it might try to do things (such as write to
+ log files) that make the situation even worse.
- 4. Changes to the "personal" filter test:
+ Like the QUIT ACL, this new ACL is provided to make it possible to gather
+ statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
+ modifier is forbidden in this ACL.
- (1) 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.
+ When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
+ to a string that indicates the reason for the termination of the SMTP
+ connection. The possible values are:
- (2) If the message contains any header line starting with "List-" it is
- treated as non-personal.
+ acl-drop Another ACL issued a "drop" command
+ bad-commands Too many unknown or non-mail commands
+ command-timeout Timeout while reading SMTP commands
+ connection-lost The SMTP connection has been lost
+ data-timeout Timeout while reading message data
+ local-scan-error The local_scan() function crashed
+ local-scan-timeout The local_scan() function timed out
+ signal-exit SIGTERM or SIGINT
+ synchronization-error SMTP synchronization error
+ tls-failed TLS failed to start
- (3) The test for "circular" in the Subject: header line has been removed
- because it now seems ill-conceived.
+ In most cases when an SMTP connection is closed without having received
+ QUIT, Exim sends an SMTP response message before actually closing the
+ connection. With the exception of acl-drop, the default message can be
+ overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
+ "drop" verb in another ACL, it is the message from the other ACL that is
+ used.
- 5. The autoreply transport has a new option called never_mail. This is an
- address list. If any run of the transport creates a message with a
- recipient that matches any item in the list, that recipient is quietly
- discarded. If all recipients are discarded, no message is created.
+10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
+ servers with individual queries. This is done by starting the query with
+ "servers=x:y:z;", where each item in the list may take one of two forms:
+ (1) If it is just a host name, the appropriate global option (mysql_servers
+ or pgsql_servers) is searched for a host of the same name, and the
+ remaining parameters (database, user, password) are taken from there.
-Version 4.40
+ (2) If it contains any slashes, it is taken as a complete parameter set.
+
+ The list of servers is used in exactly the same was as the global list.
+ Once a connection to a server has happened and a query has been
+ successfully executed, processing of the lookup ceases.
+
+ This feature is intended for use in master/slave situations where updates
+ are occurring, and one wants to update a master rather than a slave. If the
+ masters are in the list for reading, you might have:
+
+ mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
+
+ In an updating lookup, you could then write
+
+ ${lookup mysql{servers=master; UPDATE ...}
+
+ If, on the other hand, the master is not to be used for reading lookups:
+
+ pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
+
+ you can still update the master by
+
+ ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
+
+11. The message_body_newlines option (default FALSE, for backwards
+ compatibility) can be used to control whether newlines are present in
+ $message_body and $message_body_end. If it is FALSE, they are replaced by
+ spaces.
+
+
+Version 4.67
------------
-The documentation is up-to-date for the 4.40 release. What follows here is a
-brief list of the new features that have been added since 4.30.
+ 1. There is a new log selector called smtp_no_mail, which is not included in
+ the default setting. When it is set, a line is written to the main log
+ whenever an accepted SMTP connection terminates without having issued a
+ MAIL command.
+
+ 2. When an item in a dnslists list is followed by = and & and a list of IP
+ addresses, the behaviour was not clear when the lookup returned more than
+ one IP address. This has been solved by the addition of == and =& for "all"
+ rather than the default "any" matching.
- 1. log_incoming_interface affects more log lines.
+ 3. Up till now, the only control over which cipher suites GnuTLS uses has been
+ for the cipher algorithms. New options have been added to allow some of the
+ other parameters to be varied.
- 2. New ACL modifier "control = submission".
+ 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
+ set, Exim compiles a runtime option called disable_fsync.
- 3. CONFIGURE_OWNER can be set at build time to define an alternative owner for
- the configuration file, in addition to root and exim.
+ 5. There is a new variable called $smtp_count_at_connection_start.
- 4. Added expansion variables $body_zerocount, $recipient_data, and
- $sender_data.
+ 6. There's a new control called no_pipelining.
- 5. 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.
+ 7. There are two new variables called $sending_ip_address and $sending_port.
+ These are set whenever an SMTP connection to another host has been set up.
- 6. The special item "+ignore_unknown" may now appear in host lists.
+ 8. The expansion of the helo_data option in the smtp transport now happens
+ after the connection to the server has been made.
- 7. The special domain-matching patterns @mx_any, @mx_primary, and
- @mx_secondary can now be followed by "/ignore=<ip list>".
+ 9. There is a new expansion operator ${rfc2047d: that decodes strings that
+ are encoded as per RFC 2047.
- 8. New expansion conditions: match_domain, match_address, match_local_part,
- lt, lti, le, lei, gt, gti, ge, and new expansion operators time_interval,
- eval10, and base62d.
+10. There is a new log selector called "pid", which causes the current process
+ id to be added to every log line, in square brackets, immediately after the
+ time and date.
- 9. New lookup type called "iplsearch".
+11. Exim has been modified so that it flushes SMTP output before implementing
+ a delay in an ACL. It also flushes the output before performing a callout,
+ as this can take a substantial time. These behaviours can be disabled by
+ obeying control = no_delay_flush or control = no_callout_flush,
+ respectively, at some earlier stage of the connection.
-10. New log selectors ident_timeout, tls_certificate_verified, queue_time,
- deliver_time, outgoing_port, return_path_on_delivery.
+12. There are two new expansion conditions that iterate over a list. They are
+ called forany and forall.
-11. New global options smtp_active_hostname and tls_require_ciphers.
+13. There's a new global option called dsn_from that can be used to vary the
+ contents of From: lines in bounces and other automatically generated
+ messages ("delivery status notifications" - hence the name of the option).
-12. Exinext has -C and -D options.
+14. The smtp transport has a new option called hosts_avoid_pipelining.
+
+15. By default, exigrep does case-insensitive matches. There is now a -I option
+ that makes it case-sensitive.
+
+16. A number of new features ("addresses", "map", "filter", and "reduce") have
+ been added to string expansions to make it easier to process lists of
+ items, typically addresses.
+
+17. There's a new ACL modifier called "continue". It does nothing of itself,
+ and processing of the ACL always continues with the next condition or
+ modifier. It is provided so that the side effects of expanding its argument
+ can be used.
+
+18. It is now possible to use newline and other control characters (those with
+ values less than 32, plus DEL) as separators in lists.
+
+19. The exigrep utility now has a -v option, which inverts the matching
+ condition.
+
+20. The host_find_failed option in the manualroute router can now be set to
+ "ignore".
+
+
+Version 4.66
+------------
+
+No new features were added to 4.66.
+
+
+Version 4.65
+------------
+
+No new features were added to 4.65.
+
+
+Version 4.64
+------------
+
+ 1. ACL variables can now be given arbitrary names, as long as they start with
+ "acl_c" or "acl_m" (for connection variables and message variables), are at
+ least six characters long, with the sixth character being either a digit or
+ an underscore.
+
+ 2. There is a new ACL modifier called log_reject_target. It makes it possible
+ to specify which logs are used for messages about ACL rejections.
+
+ 3. There is a new authenticator called "dovecot". This is an interface to the
+ authentication facility of the Dovecot POP/IMAP server, which can support a
+ number of authentication methods.
+
+ 4. The variable $message_headers_raw provides a concatenation of all the
+ messages's headers without any decoding. This is in contrast to
+ $message_headers, which does RFC2047 decoding on the header contents.
+
+ 5. In a DNS black list, if two domain names, comma-separated, are given, the
+ second is used first to do an initial check, making use of any IP value
+ restrictions that are set. If there is a match, the first domain is used,
+ without any IP value restrictions, to get the TXT record.
+
+ 6. All authenticators now have a server_condition option.
+
+ 7. There is a new command-line option called -Mset. It is useful only in
+ conjunction with -be (that is, when testing string expansions). It must be
+ followed by a message id; Exim loads the given message from its spool
+ before doing the expansions.
+
+ 8. Another similar new command-line option is called -bem. It operates like
+ -be except that it must be followed by the name of a file that contains a
+ message.
+
+ 9. When an address is delayed because of a 4xx response to a RCPT command, it
+ is now the combination of sender and recipient that is delayed in
+ subsequent queue runs until its retry time is reached.
+
+10. Unary negation and the bitwise logical operators and, or, xor, not, and
+ shift, have been added to the eval: and eval10: expansion items.
+
+11. The variables $interface_address and $interface_port have been renamed
+ as $received_ip_address and $received_port, to make it clear that they
+ relate to message reception rather than delivery. (The old names remain
+ available for compatibility.)
+
+12. The "message" modifier can now be used on "accept" and "discard" acl verbs
+ to vary the message that is sent when an SMTP command is accepted.
+
+
+Version 4.63
+------------
+
+1. There is a new Boolean option called filter_prepend_home for the redirect
+ router.
+
+2. There is a new acl, set by acl_not_smtp_start, which is run right at the
+ start of receiving a non-SMTP message, before any of the message has been
+ read.
+
+3. When an SMTP error message is specified in a "message" modifier in an ACL,
+ or in a :fail: or :defer: message in a redirect router, Exim now checks the
+ start of the message for an SMTP error code.
+
+4. There is a new parameter for LDAP lookups called "referrals", which takes
+ one of the settings "follow" (the default) or "nofollow".
+
+5. Version 20070721.2 of exipick now included, offering these new options:
+ --reverse
+ After all other sorting options have bee processed, reverse order
+ before displaying messages (-R is synonym).
+ --random
+ Randomize order of matching messages before displaying.
+ --size
+ Instead of displaying the matching messages, display the sum
+ of their sizes.
+ --sort <variable>[,<variable>...]
+ Before displaying matching messages, sort the messages according to
+ each messages value for each variable.
+ --not
+ Negate the value for every test (returns inverse output from the
+ same criteria without --not).
+
+
+Version 4.62
+------------
+
+1. The ${readsocket expansion item now supports Internet domain sockets as well
+ as Unix domain sockets. If the first argument begins "inet:", it must be of
+ the form "inet:host:port". The port is mandatory; it may be a number or the
+ name of a TCP port in /etc/services. The host may be a name, or it may be an
+ IP address. An ip address may optionally be enclosed in square brackets.
+ This is best for IPv6 addresses. For example:
+
+ ${readsocket{inet:[::1]:1234}{<request data>}...
+
+ Only a single host name may be given, but if looking it up yield more than
+ one IP address, they are each tried in turn until a connection is made. Once
+ a connection has been made, the behaviour is as for ${readsocket with a Unix
+ domain socket.
+
+2. If a redirect router sets up file or pipe deliveries for more than one
+ incoming address, and the relevant transport has batch_max set greater than
+ one, a batch delivery now occurs.
+
+3. The appendfile transport has a new option called maildirfolder_create_regex.
+ Its value is a regular expression. For a maildir delivery, this is matched
+ against the maildir directory; if it matches, Exim ensures that a
+ maildirfolder file is created alongside the new, cur, and tmp directories.
+
+
+Version 4.61
+------------
+
+The documentation is up-to-date for the 4.61 release. Major new features since
+the 4.60 release are:
+
+. An option called disable_ipv6, to disable the use of IPv6 completely.
+
+. An increase in the number of ACL variables to 20 of each type.
+
+. A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
+ $2, $3, (though those are still set) because the numeric variables get used
+ for other things in complicated expansions.
+
+. The default for rfc1413_query_timeout has been changed from 30s to 5s.
+
+. It is possible to use setclassresources() on some BSD OS to control the
+ resources used in pipe deliveries.
+
+. A new ACL modifier called add_header, which can be used with any verb.
+
+. More errors are detectable in retry rules.
+
+There are a number of other additions too.
+
+
+Version 4.60
+------------
-13. "domainlist_cache" forces caching of an apparently variable list.
+The documentation is up-to-date for the 4.60 release. Major new features since
+the 4.50 release are:
-14. For compatibility with Sendmail, the command line option -prval:sval
- is equivalent to -oMr rval -oMs sval.
+. Support for SQLite.
-15. New callout options use_sender and use_postmaster for use when verifying
- recipients.
+. Support for IGNOREQUOTA in LMTP.
-16. John Jetmore's "exipick" utility has been added to the distribution.
+. Extensions to the "submission mode" features.
-17. The TLS code now supports CRLs.
+. Support for Client SMTP Authorization (CSA).
-18. The dnslookup router and the dnsdb lookup type now support the use of SRV
- records.
+. Support for ratelimiting hosts and users.
-19. The redirect router has a new option called qualify_domain.
+. New expansion items to help with the BATV "prvs" scheme.
-20. exigrep's output now also includes lines that are not related to any
- particular message, but which do match the pattern.
+. A "match_ip" condition, that matches an IP address against a list.
-21. New global option write_rejectlog. If it is set false, Exim no longer
- writes anything to the reject log.
+There are many more minor changes.
****
git://git.exim.org / exim.git / blobdiff