4 This file contains descriptions of new features that have been added to Exim.
5 Before a formal release, there may be quite a lot of detail so that people can
6 test from the snapshots or the Git before the documentation is updated. Once
7 the documentation is updated, this file is reduced to a short list.
12 1. ${l_header:<name>} and ${l_h:<name>} expansion items, giving a colon-sep
13 list when there are multiple headers having a given name. This matters
14 when individual headers are wrapped onto multiple lines; with previous
15 facilities hard to parse.
17 2. The ${readsocket } expansion item now takes a "tls" option, doing the
23 1. Dual-certificate stacks on servers now support OCSP stapling, under GnuTLS
24 version 3.5.6 or later.
26 2. DANE is now supported under GnuTLS version 3.0.0 or later. Both GnuTLS and
27 OpenSSL versions are moved to mainline support from Experimental.
28 New SMTP transport option "dane_require_tls_ciphers".
30 3. Feature macros for the compiled-in set of malware scanner interfaces.
32 4. SPF support is promoted from Experimental to mainline status. The template
33 src/EDITME makefile does not enable its inclusion.
35 5. Logging control for DKIM verification. The existing DKIM log line is
36 controlled by a "dkim_verbose" selector which is _not_ enabled by default.
37 A new tag "DKIM=<domain>" is added to <= lines by default, controlled by
38 a "dkim" log_selector.
40 6. Receive duration on <= lines, under a new log_selector "receive_time".
42 7. Options "ipv4_only" and "ipv4_prefer" on the dnslookup router and on
43 routing rules in the manualroute router.
45 8. Expansion item ${sha3:<string>} / ${sha3_<N>:<string>} now also supported
46 under OpenSSL version 1.1.1 or later.
48 9. DKIM operations can now use the Ed25519 algorithm in addition to RSA, under
49 GnuTLS 3.6.0 or OpenSSL 1.1.1 or later.
51 10. Builtin feature-macros _CRYPTO_HASH_SHA3 and _CRYPTO_SIGN_ED25519, library
54 11. "exim -bP macro <name>" returns caller-usable status.
56 12. Expansion item ${authresults {<machine>}} for creating an
57 Authentication-Results: header.
59 13. EXPERIMENTAL_ARC. See the experimental.spec file.
60 See also new util/renew-opendmarc-tlds.sh script for use with DMARC/ARC.
62 14: A dane:fail event, intended to facilitate reporting.
64 15. "Lightweight" support for Redis Cluster. Requires redis_servers list to
65 contain all the servers in the cluster, all of which must be reachable from
66 the running exim instance. If the cluster has master/slave replication, the
67 list must contain all the master and slave servers.
69 16. Add an option to the Avast scanner interface: "pass_unscanned". This
70 allows to treat unscanned files as clean. Files may be unscanned for
71 several reasons: decompression bombs, broken archives.
77 1. PKG_CONFIG_PATH can now be set in Local/Makefile;
78 wildcards will be expanded, values are collapsed.
80 2. The ${readsocket } expansion now takes an option to not shutdown the
81 connection after sending the query string. The default remains to do so.
83 3. An smtp transport option "hosts_noproxy_tls" to control whether multiple
84 deliveries on a single TCP connection can maintain a TLS connection
85 open. By default disabled for all hosts, doing so saves the cost of
86 making new TLS sessions, at the cost of having to proxy the data via
87 another process. Logging is also affected.
89 4. A malware connection type for the FPSCAND protocol.
91 5. An option for recipient verify callouts to hold the connection open for
92 further recipients and for delivery.
94 6. The reproducible build $SOURCE_DATE_EPOCH environment variable is now
97 7. Optionally, an alternate format for spool data-files which matches the
98 wire format - meaning more efficient reception and transmission (at the
99 cost of difficulty with standard Unix tools). Only used for messages
100 received using the ESMTP CHUNKING option, and when a new main-section
101 option "spool_wireformat" (false by default) is set.
103 8. New main configuration option "commandline_checks_require_admin" to
104 restrict who can use various introspection options.
106 9. New option modifier "no_check" for quota and quota_filecount
107 appendfile transport.
109 10. Variable $smtp_command_history returning a comma-sep list of recent
112 11. Millisecond timetamps in logs, on log_selector "millisec". Also affects
113 log elements QT, DT and D, and timstamps in debug output.
115 12. TCP Fast Open logging. As a server, logs when the SMTP banner was sent
116 while still in SYN_RECV state; as a client logs when the connection
117 is opened with a TFO cookie.
119 13. DKIM support for multiple signing, by domain and/or key-selector.
120 DKIM support for multiple hashes, and for alternate-identity tags.
121 Builtin macro with default list of signed headers.
122 Better syntax for specifying oversigning.
123 The DKIM ACL can override verification status, and status is visible in
126 14. Exipick understands -C|--config for an alternative Exim
129 15. TCP Fast Open used, with data-on-SYN, for client SMTP via SOCKS5 proxy,
130 for ${readsocket } expansions, and for ClamAV.
132 16. The "-be" expansion test mode now supports macros. Macros are expanded
133 in test lines, and new macros can be defined.
135 17. Support for server-side dual-certificate-stacks (eg. RSA + ECDSA).
141 1. Allow relative config file names for ".include"
143 2. A main-section config option "debug_store" to control the checks on
144 variable locations during store-reset. Normally false but can be enabled
145 when a memory corrution issue is suspected on a production system.
151 1. The new perl_taintmode option allows to run the embedded perl
152 interpreter in taint mode.
154 2. New log_selector: dnssec, adds a "DS" tag to acceptance and delivery lines.
156 3. Speculative debugging, via a "kill" option to the "control=debug" ACL
159 4. New expansion item ${sha3:<string>} / ${sha3_<N>:<string>}.
160 N can be 224, 256 (default), 384, 512.
161 With GnuTLS 3.5.0 or later, only.
163 5. Facility for named queues: A command-line argument can specify
164 the queue name for a queue operation, and an ACL modifier can set
165 the queue to be used for a message. A $queue_name variable gives
168 6. New expansion operators base32/base32d.
170 7. The CHUNKING ESMTP extension from RFC 3030. May give some slight
171 performance increase and network load decrease. Main config option
172 chunking_advertise_hosts, and smtp transport option hosts_try_chunking
175 8. LMDB lookup support, as Experimental. Patch supplied by Andrew Colin Kissa.
177 9. Expansion operator escape8bit, like escape but not touching newline etc..
179 10. Feature macros, generated from compile options. All start with "_HAVE_"
180 and go on with some roughly recognisable name. Driver macros, for
181 router, transport and authentication drivers; names starting with "_DRIVER_".
182 Option macros, for each configuration-file option; all start with "_OPT_".
183 Use the "-bP macros" command-line option to see what is present.
185 11. Integer values for options can take a "G" multiplier.
187 12. defer=pass option for the ACL control cutthrough_delivery, to reflect 4xx
188 returns from the target back to the initiator, rather than spooling the
191 13. New built-in constants available for tls_dhparam and default changed.
193 14. If built with EXPERIMENTAL_QUEUEFILE, a queuefile transport, for writing
194 out copies of the message spool files for use by 3rd-party scanners.
196 15. A new option on the smtp transport, hosts_try_fastopen. If the system
197 supports it (on Linux it must be enabled in the kernel by the sysadmin)
198 try to use RFC 7413 "TCP Fast Open". No data is sent on the SYN segment
199 but it permits a peer that also supports the facility to send its SMTP
200 banner immediately after the SYN,ACK segment rather then waiting for
201 another ACK - so saving up to one roundtrip time. Because it requires
202 previous communication with the peer (we save a cookie from it) this
203 will only become active on frequently-contacted destinations.
205 16. A new syslog_pid option to suppress PID duplication in syslog lines.
211 1. The ACL conditions regex and mime_regex now capture substrings
212 into numeric variables $regex1 to 9, like the "match" expansion condition.
214 2. New $callout_address variable records the address used for a spam=,
215 malware= or verify= callout.
217 3. Transports now take a "max_parallel" option, to limit concurrency.
219 4. Expansion operators ${ipv6norm:<string>} and ${ipv6denorm:<string>}.
220 The latter expands to a 8-element colon-sep set of hex digits including
221 leading zeroes. A trailing ipv4-style dotted-decimal set is converted
222 to hex. Pure ipv4 addresses are converted to IPv4-mapped IPv6.
223 The former operator strips leading zeroes and collapses the longest
224 set of 0-groups to a double-colon.
226 5. New "-bP config" support, to dump the effective configuration.
228 6. New $dkim_key_length variable.
230 7. New base64d and base64 expansion items (the existing str2b64 being a
231 synonym of the latter). Add support in base64 for certificates.
233 8. New main configuration option "bounce_return_linesize_limit" to
234 avoid oversize bodies in bounces. The default value matches RFC
237 9. New $initial_cwd expansion variable.
243 1. Support for using the system standard CA bundle.
245 2. New expansion items $config_file, $config_dir, containing the file
246 and directory name of the main configuration file. Also $exim_version.
248 3. New "malware=" support for Avast.
250 4. New "spam=" variant option for Rspamd.
252 5. Assorted options on malware= and spam= scanners.
254 6. A command-line option to write a comment into the logfile.
256 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
257 be configured to make connections via socks5 proxies.
259 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
260 the transmission of UTF-8 envelope addresses.
262 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
263 used encoding of Maildir folder names.
265 10. A logging option for slow DNS lookups.
267 11. New ${env {<variable>}} expansion.
269 12. A non-SMTP authenticator using information from TLS client certificates.
271 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
272 Patch originally by Wolfgang Breyha.
274 14. Main option "dns_trust_aa" for trusting your local nameserver at the
275 same level as DNSSEC.
281 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
282 DANE SMTP draft to assess a secure chain of trust of the certificate
283 used to establish the TLS connection based on a TLSA record in the
284 domain of the sender.
286 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
287 and several new events have been created. The reason is because it has
288 been expanded beyond just firing events during the transport phase. Any
289 existing TPDA transport options will have to be rewritten to use a new
290 $event_name expansion variable in a condition. Refer to the
291 experimental-spec.txt for details and examples.
293 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
294 server certs used for TLS match the result of the MX lookup. It does
295 not use the same mechanism as DANE.
305 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
306 configured to expect an initial header from a proxy that will make the
307 actual external source IP:host be used in exim instead of the IP of the
308 proxy that is connecting to it.
310 2. New verify option header_names_ascii, which will check to make sure
311 there are no non-ASCII characters in header names. Exim itself handles
312 those non-ASCII characters, but downstream apps may not, so Exim can
313 detect and reject if those characters are present.
315 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
316 codepoints with valid ones.
318 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
319 command line and matching a regex against the return data for trigger
320 and a second regex to extract malware_name. The mail spoolfile name can
321 be included in the command line.
323 5. The smtp transport now supports options "tls_verify_hosts" and
324 "tls_try_verify_hosts". If either is set the certificate verification
325 is split from the encryption operation. The default remains that a failed
326 verification cancels the encryption.
328 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
329 lookup can now set a list of servers to use that is different from the
332 7. New command-line option -C for exiqgrep to specify alternate exim.conf
333 file when searching the queue.
335 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
337 9. Support for DNSSEC on outbound connections.
339 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
340 "certextract" to extract fields from them. Hash operators md5 and sha1
341 work over them for generating fingerprints, and a new sha256 operator
344 11. PRDR is now supported dy default.
346 12. OCSP stapling is now supported by default.
348 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
349 Delivery Status Notification messages in MIME format, and negotiate
350 DSN features per RFC 3461.
356 1. New command-line option -bI:sieve will list all supported sieve extensions
357 of this Exim build on standard output, one per line.
358 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
359 query this to establish the correct list to include in the protocol's
360 SIEVE capability line.
362 2. If the -n option is combined with the -bP option, then the name of an
363 emitted option is not output, only the value (if visible to you).
364 For instance, "exim -n -bP pid_file_path" should just emit a pathname
365 followed by a newline, and no other text.
367 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
368 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
369 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
370 acceptable for security. (Option accepted but ignored if using OpenSSL).
371 Defaults to 1024, the old value. May be lowered only to 512, or raised as
372 far as you like. Raising this may hinder TLS interoperability with other
373 sites and is not currently recommended. Lowering this will permit you to
374 establish a TLS session which is not as secure as you might like.
376 Unless you really know what you are doing, leave it alone.
378 4. If not built with DISABLE_DNSSEC, Exim now has the main option
379 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
380 to send the DO flag to your recursive resolver. If you have a recursive
381 resolver, which can set the Authenticated Data (AD) flag in results, Exim
382 can now detect this. Exim does not perform validation itself, instead
383 relying upon a trusted path to the resolver.
385 Current status: work-in-progress; $sender_host_dnssec variable added.
387 5. DSCP support for outbound connections: on a transport using the smtp driver,
388 set "dscp = ef", for instance, to cause the connections to have the relevant
389 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
391 Similarly for inbound connections, there is a new control modifier, dscp,
392 so "warn control = dscp/ef" in the connect ACL, or after authentication.
394 Supported values depend upon system libraries. "exim -bI:dscp" to list the
395 ones Exim knows of. You can also set a raw number 0..0x3F.
397 6. The -G command-line flag is no longer ignored; it is now equivalent to an
398 ACL setting "control = suppress_local_fixups". The -L command-line flag
399 is now accepted and forces use of syslog, with the provided tag as the
400 process name. A few other flags used by Sendmail are now accepted and
403 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
404 ACL modifier; works for single-recipient mails which are received on and
405 deliverable via SMTP. Using the connection made for a recipient verify,
406 if requested before the verify, or a new one made for the purpose while
407 the inbound connection is still active. The bulk of the mail item is copied
408 direct from the inbound socket to the outbound (as well as the spool file).
409 When the source notifies the end of data, the data acceptance by the destination
410 is negotiated before the acceptance is sent to the source. If the destination
411 does not accept the mail item, for example due to content-scanning, the item
412 is not accepted from the source and therefore there is no need to generate
413 a bounce mail. This is of benefit when providing a secondary-MX service.
414 The downside is that delays are under the control of the ultimate destination
417 The Received-by: header on items delivered by cutthrough is generated
418 early in reception rather than at the end; this will affect any timestamp
419 included. The log line showing delivery is recorded before that showing
420 reception; it uses a new ">>" tag instead of "=>".
422 To support the feature, verify-callout connections can now use ESMTP and TLS.
423 The usual smtp transport options are honoured, plus a (new, default everything)
424 hosts_verify_avoid_tls.
426 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
427 for specific access to the information for each connection. The old names
428 are present for now but deprecated.
430 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
432 8. New expansion operators ${listnamed:name} to get the content of a named list
433 and ${listcount:string} to count the items in a list.
435 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
436 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
437 modules. For some situations this is desirable, but we expect admin in
438 those situations to know they want the feature. More commonly, it means
439 that GUI user modules get loaded and are broken by the setuid Exim being
440 unable to access files specified in environment variables and passed
441 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
442 unless this new option is set.
444 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
445 so have also added a build option which can be used to build Exim with GnuTLS
446 but without trying to use any kind of PKCS11 support. Uncomment this in the
449 AVOID_GNUTLS_PKCS11=yes
451 10. The "acl = name" condition on an ACL now supports optional arguments.
452 New expansion item "${acl {name}{arg}...}" and expansion condition
453 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
454 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
455 Variable $acl_narg contains the number of arguments. If the ACL sets
456 a "message =" value this becomes the result of the expansion item,
457 or the value of $value for the expansion condition. If the ACL returns
458 accept the expansion condition is true; if reject, false. A defer
459 return results in a forced fail.
461 11. Routers and transports can now have multiple headers_add and headers_remove
462 option lines. The concatenated list is used.
464 12. New ACL modifier "remove_header" can remove headers before message gets
465 handled by routers/transports.
467 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
468 "aaaa" and "a" lookups is done and the full set of results returned.
470 14. New expansion variable $headers_added with content from ACL add_header
471 modifier (but not yet added to message).
473 15. New 8bitmime status logging option for received messages. Log field "M8S".
475 16. New authenticated_sender logging option, adding to log field "A".
477 17. New expansion variables $router_name and $transport_name. Useful
478 particularly for debug_print as -bt command-line option does not
479 require privilege whereas -d does.
481 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
482 proposed extension to SMTP from Eric Hall.
484 19. The pipe transport has gained the force_command option, to allow
485 decorating commands from user .forward pipe aliases with prefix
486 wrappers, for instance.
488 20. Callout connections can now AUTH; the same controls as normal delivery
491 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
492 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
493 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
494 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
495 dmarc_status. It adds new control flags dmarc_disable_verify and
496 dmarc_enable_forensic. The default for the dmarc_tld_file option is
497 "/etc/exim/opendmarc.tlds" and can be changed via EDITME.
499 22. Add expansion variable $authenticated_fail_id, which is the username
500 provided to the authentication method which failed. It is available
501 for use in subsequent ACL processing (typically quit or notquit ACLs).
503 23. New ACL modifier "udpsend" can construct a UDP packet to send to a given
506 24. New ${hexquote:..string..} expansion operator converts non-printable
507 characters in the string to \xNN form.
509 25. Experimental TPDA (Transport Post Delivery Action) function added.
510 Patch provided by Axel Rau.
512 26. Experimental Redis lookup added. Patch provided by Warren Baker.
518 1. New authenticator driver, "gsasl". Server-only (at present).
519 This is a SASL interface, licensed under GPL, which can be found at
520 http://www.gnu.org/software/gsasl/.
521 This system does not provide sources of data for authentication, so
522 careful use needs to be made of the conditions in Exim.
524 2. New authenticator driver, "heimdal_gssapi". Server-only.
525 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
526 is no longer honoured for setuid programs by Heimdal. Use the
527 "server_keytab" option to point to the keytab.
529 3. The "pkg-config" system can now be used when building Exim to reference
530 cflags and library information for lookups and authenticators, rather
531 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
532 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
533 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
535 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
536 find the headers and libraries for PCRE.
538 4. New expansion variable $tls_bits.
540 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
541 be joined together with ASCII NUL characters to construct the key to pass
542 into the DBM library. Can be used with gsasl to access sasldb2 files as
545 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
547 Avoid release 1.0.1a if you can. Note that the default value of
548 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
549 increased susceptibility to attack. This may still have interoperability
550 implications for very old clients (see version 4.31 change 37) but
551 administrators can choose to make the trade-off themselves and restore
552 compatibility at the cost of session security.
554 7. Use of the new expansion variable $tls_sni in the main configuration option
555 tls_certificate will cause Exim to re-expand the option, if the client
556 sends the TLS Server Name Indication extension, to permit choosing a
557 different certificate; tls_privatekey will also be re-expanded. You must
558 still set these options to expand to valid files when $tls_sni is not set.
560 The SMTP Transport has gained the option tls_sni, which will set a hostname
561 for outbound TLS sessions, and set $tls_sni too.
563 A new log_selector, +tls_sni, has been added, to log received SNI values
564 for Exim as a server.
566 8. The existing "accept_8bitmime" option now defaults to true. This means
567 that Exim is deliberately not strictly RFC compliant. We're following
568 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
569 Those who disagree, or know that they are talking to mail servers that,
570 even today, are not 8-bit clean, need to turn off this option.
572 9. Exim can now be started with -bw (with an optional timeout, given as
573 -bw<timespec>). With this, stdin at startup is a socket that is
574 already listening for connections. This has a more modern name of
575 "socket activation", but forcing the activated socket to fd 0. We're
576 interested in adding more support for modern variants.
578 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
579 for numbers indicates multiplication by 1024^3.
581 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
582 gnutls_require_mac & gnutls_require_protocols are no longer supported.
583 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
584 string, documentation for which is at:
585 http://www.gnutls.org/manual/html_node/Priority-Strings.html
587 SNI support has been added to Exim's GnuTLS integration too.
589 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
590 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
592 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
593 is now available. If the contents of the file are valid, then Exim will
594 send that back in response to a TLS status request; this is OCSP Stapling.
595 Exim will not maintain the contents of the file in any way: administrators
596 are responsible for ensuring that it is up-to-date.
598 See "experimental-spec.txt" for more details.
600 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
601 identically to TXT record lookups.
603 14. New expansion variable $tod_epoch_l for higher-precision time.
605 15. New global option tls_dh_max_bits, defaulting to current value of NSS
606 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
607 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
609 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
610 Option can now be a path or an identifier for a standard prime.
611 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
612 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
615 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
616 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
617 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
623 1. New options for the ratelimit ACL condition: /count= and /unique=.
624 The /noupdate option has been replaced by a /readonly option.
626 2. The SMTP transport's protocol option may now be set to "smtps", to
627 use SSL-on-connect outbound.
629 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
630 there is a problem talking to the AV scanner, or the AV scanner running.
632 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
633 and check if the search item is a member of the list. This does not
634 support named lists, but does subject the list part to string expansion.
636 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
637 built, Exim no longer performs string expansion on the second string of
638 the match_* expansion conditions: "match_address", "match_domain",
639 "match_ip" & "match_local_part". Named lists can still be used.
645 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
646 or off in the resolver library.
652 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
653 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
654 libraries. The following global options have been added in support of
655 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
656 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
658 2. The pipe transport now takes a boolean option, "freeze_signal", default
659 false. When true, if the external delivery command exits on a signal then
660 Exim will freeze the message in the queue, instead of generating a bounce.
662 3. Log filenames may now use %M as an escape, instead of %D (still available).
663 The %M pattern expands to yyyymm, providing month-level resolution.
665 4. The $message_linecount variable is now updated for the maildir_tag option,
666 in the same way as $message_size, to reflect the real number of lines,
667 including any header additions or removals from transport.
669 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
670 Exim now selects entries randomly, to better scale in a cluster setup.
676 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
677 the flaw permitted the Exim run-time user to cause root to append to
678 arbitrary files of the attacker's choosing, with the content based
679 on content supplied by the attacker.
681 2. Exim now supports loading some lookup types at run-time, using your
682 platform's dlopen() functionality. This has limited platform support
683 and the intention is not to support every variant, it's limited to
684 dlopen(). This permits the main Exim binary to not be linked against
685 all the libraries needed for all the lookup types.
691 NOTE: this version is not guaranteed backwards-compatible, please read the
692 items below carefully
694 1. A new main configuration option, "openssl_options", is available if Exim
695 is built with SSL support provided by OpenSSL. The option allows
696 administrators to specify OpenSSL options to be used on connections;
697 typically this is to set bug compatibility features which the OpenSSL
698 developers have not enabled by default. There may be security
699 consequences for certain options, so these should not be changed
702 2. A new pipe transport option, "permit_coredumps", may help with problem
703 diagnosis in some scenarios. Note that Exim is typically installed as
704 a setuid binary, which on most OSes will inhibit coredumps by default,
705 so that safety mechanism would have to be overridden for this option to
706 be able to take effect.
708 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
709 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
710 Note that this switches Exim to use a new API ("INSTREAM") and a future
711 release of ClamAV will remove support for the old API ("STREAM").
713 The av_scanner option, when set to "clamd", now takes an optional third
714 part, "local", which causes Exim to pass a filename to ClamAV instead of
715 the file content. This is the same behaviour as when clamd is pointed at
716 a Unix-domain socket. For example:
718 av_scanner = clamd:192.0.2.3 1234:local
720 ClamAV's ExtendedDetectionInfo response format is now handled.
722 4. There is now a -bmalware option, restricted to admin users. This option
723 takes one parameter, a filename, and scans that file with Exim's
724 malware-scanning framework. This is intended purely as a debugging aid
725 to ensure that Exim's scanning is working, not to replace other tools.
726 Note that the ACL framework is not invoked, so if av_scanner references
727 ACL variables without a fallback then this will fail.
729 5. There is a new expansion operator, "reverse_ip", which will reverse IP
730 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
732 ${reverse_ip:192.0.2.4}
734 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
735 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
737 6. There is a new ACL control called "debug", to enable debug logging.
738 This allows selective logging of certain incoming transactions within
739 production environments, with some care. It takes two options, "tag"
740 and "opts"; "tag" is included in the filename of the log and "opts"
741 is used as per the -d<options> command-line option. Examples, which
742 don't all make sense in all contexts:
745 control = debug/tag=.$sender_host_address
746 control = debug/opts=+expand+acl
747 control = debug/tag=.$message_exim_id/opts=+expand
749 7. It has always been implicit in the design and the documentation that
750 "the Exim user" is not root. src/EDITME said that using root was
751 "very strongly discouraged". This is not enough to keep people from
752 shooting themselves in the foot in days when many don't configure Exim
753 themselves but via package build managers. The security consequences of
754 running various bits of network code are severe if there should be bugs in
755 them. As such, the Exim user may no longer be root. If configured
756 statically, Exim will refuse to build. If configured as ref:user then Exim
757 will exit shortly after start-up. If you must shoot yourself in the foot,
758 then henceforth you will have to maintain your own local patches to strip
761 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
762 condition logic to determine truth/failure and will fail to expand many
763 strings, bool_lax{} uses the router condition logic, where most strings
765 Note: bool{00} is false, bool_lax{00} is true.
767 9. Routers now support multiple "condition" tests.
769 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
770 Setting this allows an admin to define which entry in the tcpwrappers
771 config file will be used to control access to the daemon. This option
772 is only available when Exim is built with USE_TCP_WRAPPERS. The
773 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
776 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
777 the Exim run-time user, instead of root.
779 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
780 is forced on. This is mitigated by the new build option
781 TRUSTED_CONFIG_LIST which defines a list of configuration files which
782 are trusted; one per line. If a config file is owned by root and matches
783 a pathname in the list, then it may be invoked by the Exim build-time
784 user without Exim relinquishing root privileges.
786 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
787 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
788 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
789 include the main config. As a transition mechanism, we are temporarily
790 providing a work-around: the new build option WHITELIST_D_MACROS provides
791 a colon-separated list of macro names which may be overridden by the Exim
792 run-time user. The values of these macros are constrained to the regex
793 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
799 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
800 writable, the other to locking of MBX folders (not mbox).
802 2. MySQL stored procedures are now supported.
804 3. The dkim_domain transport option is now a list, not a single string, and
805 messages will be signed for each element in the list (discarding
808 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
809 in the presence of multiple character strings within the RR. Prior to 4.70,
810 only the first string would be returned. The dnsdb lookup now, by default,
811 preserves the pre-4.70 semantics, but also now takes an extended output
812 separator specification. The separator can be followed by a semicolon, to
813 concatenate the individual text strings together with no join character,
814 or by a comma and a second separator character, in which case the text
815 strings within a TXT record are joined on that second character.
816 Administrators are reminded that DNS provides no ordering guarantees
817 between multiple records in an RRset. For example:
819 foo.example. IN TXT "a" "b" "c"
820 foo.example. IN TXT "d" "e" "f"
822 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
823 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
824 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
830 1. Native DKIM support without an external library.
831 (Note that if no action to prevent it is taken, a straight upgrade will
832 result in DKIM verification of all signed incoming emails. See spec
833 for details on conditionally disabling)
835 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
837 3. There is now a bool{} expansion condition which maps certain strings to
838 true/false condition values (most likely of use in conjunction with the
839 and{} expansion operator).
841 4. The $spam_score, $spam_bar and $spam_report variables are now available
844 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
845 options, provided that Exim is invoked by an admin_user.
847 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
848 which increases compatibility with older clients at the cost of decreased
849 security. Don't set this unless you need to support such clients.
851 7. There is a new expansion operator, ${randint:...} which will produce a
852 "random" number less than the supplied integer. This randomness is
853 not guaranteed to be cryptographically strong, but depending upon how
854 Exim was built may be better than the most naive schemes.
856 8. Exim now explicitly ensures that SHA256 is available when linked against
859 9. The transport_filter_timeout option now applies to SMTP transports too.
865 1. Preliminary DKIM support in Experimental.
871 1. The body_linecount and body_zerocount C variables are now exported in the
874 2. When a dnslists lookup succeeds, the key that was looked up is now placed
875 in $dnslist_matched. When the key is an IP address, it is not reversed in
876 this variable (though it is, of course, in the actual lookup). In simple
879 deny dnslists = spamhaus.example
881 the key is also available in another variable (in this case,
882 $sender_host_address). In more complicated cases, however, this is not
883 true. For example, using a data lookup might generate a dnslists lookup
886 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
888 If this condition succeeds, the value in $dnslist_matched might be
889 192.168.6.7 (for example).
891 3. Authenticators now have a client_condition option. When Exim is running as
892 a client, it skips an authenticator whose client_condition expansion yields
893 "0", "no", or "false". This can be used, for example, to skip plain text
894 authenticators when the connection is not encrypted by a setting such as:
896 client_condition = ${if !eq{$tls_cipher}{}}
898 Note that the 4.67 documentation states that $tls_cipher contains the
899 cipher used for incoming messages. In fact, during SMTP delivery, it
900 contains the cipher used for the delivery. The same is true for
903 4. There is now a -Mvc <message-id> option, which outputs a copy of the
904 message to the standard output, in RFC 2822 format. The option can be used
905 only by an admin user.
907 5. There is now a /noupdate option for the ratelimit ACL condition. It
908 computes the rate and checks the limit as normal, but it does not update
909 the saved data. This means that, in relevant ACLs, it is possible to lookup
910 the existence of a specified (or auto-generated) ratelimit key without
911 incrementing the ratelimit counter for that key.
913 In order for this to be useful, another ACL entry must set the rate
914 for the same key somewhere (otherwise it will always be zero).
919 # Read the rate; if it doesn't exist or is below the maximum
921 deny ratelimit = 100 / 5m / strict / noupdate
922 log_message = RATE: $sender_rate / $sender_rate_period \
923 (max $sender_rate_limit)
925 [... some other logic and tests...]
927 warn ratelimit = 100 / 5m / strict / per_cmd
928 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
929 (max $sender_rate_limit)
930 condition = ${if le{$sender_rate}{$sender_rate_limit}}
934 6. The variable $max_received_linelength contains the number of bytes in the
935 longest line that was received as part of the message, not counting the
936 line termination character(s).
938 7. Host lists can now include +ignore_defer and +include_defer, analagous to
939 +ignore_unknown and +include_unknown. These options should be used with
940 care, probably only in non-critical host lists such as whitelists.
942 8. There's a new option called queue_only_load_latch, which defaults true.
943 If set false when queue_only_load is greater than zero, Exim re-evaluates
944 the load for each incoming message in an SMTP session. Otherwise, once one
945 message is queued, the remainder are also.
947 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
948 cases when an SMTP session ends without sending QUIT. However, when Exim
949 itself is is bad trouble, such as being unable to write to its log files,
950 this ACL is not run, because it might try to do things (such as write to
951 log files) that make the situation even worse.
953 Like the QUIT ACL, this new ACL is provided to make it possible to gather
954 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
955 modifier is forbidden in this ACL.
957 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
958 to a string that indicates the reason for the termination of the SMTP
959 connection. The possible values are:
961 acl-drop Another ACL issued a "drop" command
962 bad-commands Too many unknown or non-mail commands
963 command-timeout Timeout while reading SMTP commands
964 connection-lost The SMTP connection has been lost
965 data-timeout Timeout while reading message data
966 local-scan-error The local_scan() function crashed
967 local-scan-timeout The local_scan() function timed out
968 signal-exit SIGTERM or SIGINT
969 synchronization-error SMTP synchronization error
970 tls-failed TLS failed to start
972 In most cases when an SMTP connection is closed without having received
973 QUIT, Exim sends an SMTP response message before actually closing the
974 connection. With the exception of acl-drop, the default message can be
975 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
976 "drop" verb in another ACL, it is the message from the other ACL that is
979 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
980 servers with individual queries. This is done by starting the query with
981 "servers=x:y:z;", where each item in the list may take one of two forms:
983 (1) If it is just a host name, the appropriate global option (mysql_servers
984 or pgsql_servers) is searched for a host of the same name, and the
985 remaining parameters (database, user, password) are taken from there.
987 (2) If it contains any slashes, it is taken as a complete parameter set.
989 The list of servers is used in exactly the same was as the global list.
990 Once a connection to a server has happened and a query has been
991 successfully executed, processing of the lookup ceases.
993 This feature is intended for use in master/slave situations where updates
994 are occurring, and one wants to update a master rather than a slave. If the
995 masters are in the list for reading, you might have:
997 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
999 In an updating lookup, you could then write
1001 ${lookup mysql{servers=master; UPDATE ...}
1003 If, on the other hand, the master is not to be used for reading lookups:
1005 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
1007 you can still update the master by
1009 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
1011 11. The message_body_newlines option (default FALSE, for backwards
1012 compatibility) can be used to control whether newlines are present in
1013 $message_body and $message_body_end. If it is FALSE, they are replaced by
1020 1. There is a new log selector called smtp_no_mail, which is not included in
1021 the default setting. When it is set, a line is written to the main log
1022 whenever an accepted SMTP connection terminates without having issued a
1025 2. When an item in a dnslists list is followed by = and & and a list of IP
1026 addresses, the behaviour was not clear when the lookup returned more than
1027 one IP address. This has been solved by the addition of == and =& for "all"
1028 rather than the default "any" matching.
1030 3. Up till now, the only control over which cipher suites GnuTLS uses has been
1031 for the cipher algorithms. New options have been added to allow some of the
1032 other parameters to be varied.
1034 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
1035 set, Exim compiles a runtime option called disable_fsync.
1037 5. There is a new variable called $smtp_count_at_connection_start.
1039 6. There's a new control called no_pipelining.
1041 7. There are two new variables called $sending_ip_address and $sending_port.
1042 These are set whenever an SMTP connection to another host has been set up.
1044 8. The expansion of the helo_data option in the smtp transport now happens
1045 after the connection to the server has been made.
1047 9. There is a new expansion operator ${rfc2047d: that decodes strings that
1048 are encoded as per RFC 2047.
1050 10. There is a new log selector called "pid", which causes the current process
1051 id to be added to every log line, in square brackets, immediately after the
1054 11. Exim has been modified so that it flushes SMTP output before implementing
1055 a delay in an ACL. It also flushes the output before performing a callout,
1056 as this can take a substantial time. These behaviours can be disabled by
1057 obeying control = no_delay_flush or control = no_callout_flush,
1058 respectively, at some earlier stage of the connection.
1060 12. There are two new expansion conditions that iterate over a list. They are
1061 called forany and forall.
1063 13. There's a new global option called dsn_from that can be used to vary the
1064 contents of From: lines in bounces and other automatically generated
1065 messages ("delivery status notifications" - hence the name of the option).
1067 14. The smtp transport has a new option called hosts_avoid_pipelining.
1069 15. By default, exigrep does case-insensitive matches. There is now a -I option
1070 that makes it case-sensitive.
1072 16. A number of new features ("addresses", "map", "filter", and "reduce") have
1073 been added to string expansions to make it easier to process lists of
1074 items, typically addresses.
1076 17. There's a new ACL modifier called "continue". It does nothing of itself,
1077 and processing of the ACL always continues with the next condition or
1078 modifier. It is provided so that the side effects of expanding its argument
1081 18. It is now possible to use newline and other control characters (those with
1082 values less than 32, plus DEL) as separators in lists.
1084 19. The exigrep utility now has a -v option, which inverts the matching
1087 20. The host_find_failed option in the manualroute router can now be set to
1094 No new features were added to 4.66.
1100 No new features were added to 4.65.
1106 1. ACL variables can now be given arbitrary names, as long as they start with
1107 "acl_c" or "acl_m" (for connection variables and message variables), are at
1108 least six characters long, with the sixth character being either a digit or
1111 2. There is a new ACL modifier called log_reject_target. It makes it possible
1112 to specify which logs are used for messages about ACL rejections.
1114 3. There is a new authenticator called "dovecot". This is an interface to the
1115 authentication facility of the Dovecot POP/IMAP server, which can support a
1116 number of authentication methods.
1118 4. The variable $message_headers_raw provides a concatenation of all the
1119 messages's headers without any decoding. This is in contrast to
1120 $message_headers, which does RFC2047 decoding on the header contents.
1122 5. In a DNS black list, if two domain names, comma-separated, are given, the
1123 second is used first to do an initial check, making use of any IP value
1124 restrictions that are set. If there is a match, the first domain is used,
1125 without any IP value restrictions, to get the TXT record.
1127 6. All authenticators now have a server_condition option.
1129 7. There is a new command-line option called -Mset. It is useful only in
1130 conjunction with -be (that is, when testing string expansions). It must be
1131 followed by a message id; Exim loads the given message from its spool
1132 before doing the expansions.
1134 8. Another similar new command-line option is called -bem. It operates like
1135 -be except that it must be followed by the name of a file that contains a
1138 9. When an address is delayed because of a 4xx response to a RCPT command, it
1139 is now the combination of sender and recipient that is delayed in
1140 subsequent queue runs until its retry time is reached.
1142 10. Unary negation and the bitwise logical operators and, or, xor, not, and
1143 shift, have been added to the eval: and eval10: expansion items.
1145 11. The variables $interface_address and $interface_port have been renamed
1146 as $received_ip_address and $received_port, to make it clear that they
1147 relate to message reception rather than delivery. (The old names remain
1148 available for compatibility.)
1150 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
1151 to vary the message that is sent when an SMTP command is accepted.
1157 1. There is a new Boolean option called filter_prepend_home for the redirect
1160 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
1161 start of receiving a non-SMTP message, before any of the message has been
1164 3. When an SMTP error message is specified in a "message" modifier in an ACL,
1165 or in a :fail: or :defer: message in a redirect router, Exim now checks the
1166 start of the message for an SMTP error code.
1168 4. There is a new parameter for LDAP lookups called "referrals", which takes
1169 one of the settings "follow" (the default) or "nofollow".
1171 5. Version 20070721.2 of exipick now included, offering these new options:
1173 After all other sorting options have bee processed, reverse order
1174 before displaying messages (-R is synonym).
1176 Randomize order of matching messages before displaying.
1178 Instead of displaying the matching messages, display the sum
1180 --sort <variable>[,<variable>...]
1181 Before displaying matching messages, sort the messages according to
1182 each messages value for each variable.
1184 Negate the value for every test (returns inverse output from the
1185 same criteria without --not).
1191 1. The ${readsocket expansion item now supports Internet domain sockets as well
1192 as Unix domain sockets. If the first argument begins "inet:", it must be of
1193 the form "inet:host:port". The port is mandatory; it may be a number or the
1194 name of a TCP port in /etc/services. The host may be a name, or it may be an
1195 IP address. An ip address may optionally be enclosed in square brackets.
1196 This is best for IPv6 addresses. For example:
1198 ${readsocket{inet:[::1]:1234}{<request data>}...
1200 Only a single host name may be given, but if looking it up yield more than
1201 one IP address, they are each tried in turn until a connection is made. Once
1202 a connection has been made, the behaviour is as for ${readsocket with a Unix
1205 2. If a redirect router sets up file or pipe deliveries for more than one
1206 incoming address, and the relevant transport has batch_max set greater than
1207 one, a batch delivery now occurs.
1209 3. The appendfile transport has a new option called maildirfolder_create_regex.
1210 Its value is a regular expression. For a maildir delivery, this is matched
1211 against the maildir directory; if it matches, Exim ensures that a
1212 maildirfolder file is created alongside the new, cur, and tmp directories.
1218 The documentation is up-to-date for the 4.61 release. Major new features since
1219 the 4.60 release are:
1221 . An option called disable_ipv6, to disable the use of IPv6 completely.
1223 . An increase in the number of ACL variables to 20 of each type.
1225 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
1226 $2, $3, (though those are still set) because the numeric variables get used
1227 for other things in complicated expansions.
1229 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1231 . It is possible to use setclassresources() on some BSD OS to control the
1232 resources used in pipe deliveries.
1234 . A new ACL modifier called add_header, which can be used with any verb.
1236 . More errors are detectable in retry rules.
1238 There are a number of other additions too.
1244 The documentation is up-to-date for the 4.60 release. Major new features since
1245 the 4.50 release are:
1247 . Support for SQLite.
1249 . Support for IGNOREQUOTA in LMTP.
1251 . Extensions to the "submission mode" features.
1253 . Support for Client SMTP Authorization (CSA).
1255 . Support for ratelimiting hosts and users.
1257 . New expansion items to help with the BATV "prvs" scheme.
1259 . A "match_ip" condition, that matches an IP address against a list.
1261 There are many more minor changes.
git://git.exim.org / users / jgh / exim.git / blob