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
20 3. EXPERIMENTAL_REQUIRETLS. See the experimental.spec file.
22 4. If built with SUPPORT_I18N a "utf8_downconvert" option on the smtp transport.
24 5. A "pipelining" log_selector.
26 6. Builtin macros for supported log_selector and openssl_options values.
28 7. JSON variants of the ${extract } expansion item.
30 8. A "noutf8" debug option, for disabling the UTF-8 characters in debug output.
32 9. TCP Fast Open support on MacOS.
37 1. Dual-certificate stacks on servers now support OCSP stapling, under GnuTLS
38 version 3.5.6 or later.
40 2. DANE is now supported under GnuTLS version 3.0.0 or later. Both GnuTLS and
41 OpenSSL versions are moved to mainline support from Experimental.
42 New SMTP transport option "dane_require_tls_ciphers".
44 3. Feature macros for the compiled-in set of malware scanner interfaces.
46 4. SPF support is promoted from Experimental to mainline status. The template
47 src/EDITME makefile does not enable its inclusion.
49 5. Logging control for DKIM verification. The existing DKIM log line is
50 controlled by a "dkim_verbose" selector which is _not_ enabled by default.
51 A new tag "DKIM=<domain>" is added to <= lines by default, controlled by
52 a "dkim" log_selector.
54 6. Receive duration on <= lines, under a new log_selector "receive_time".
56 7. Options "ipv4_only" and "ipv4_prefer" on the dnslookup router and on
57 routing rules in the manualroute router.
59 8. Expansion item ${sha3:<string>} / ${sha3_<N>:<string>} now also supported
60 under OpenSSL version 1.1.1 or later.
62 9. DKIM operations can now use the Ed25519 algorithm in addition to RSA, under
63 GnuTLS 3.6.0 or OpenSSL 1.1.1 or later.
65 10. Builtin feature-macros _CRYPTO_HASH_SHA3 and _CRYPTO_SIGN_ED25519, library
68 11. "exim -bP macro <name>" returns caller-usable status.
70 12. Expansion item ${authresults {<machine>}} for creating an
71 Authentication-Results: header.
73 13. EXPERIMENTAL_ARC. See the experimental.spec file.
74 See also new util/renew-opendmarc-tlds.sh script for use with DMARC/ARC.
76 14: A dane:fail event, intended to facilitate reporting.
78 15. "Lightweight" support for Redis Cluster. Requires redis_servers list to
79 contain all the servers in the cluster, all of which must be reachable from
80 the running exim instance. If the cluster has master/slave replication, the
81 list must contain all the master and slave servers.
83 16. Add an option to the Avast scanner interface: "pass_unscanned". This
84 allows to treat unscanned files as clean. Files may be unscanned for
85 several reasons: decompression bombs, broken archives.
91 1. PKG_CONFIG_PATH can now be set in Local/Makefile;
92 wildcards will be expanded, values are collapsed.
94 2. The ${readsocket } expansion now takes an option to not shutdown the
95 connection after sending the query string. The default remains to do so.
97 3. An smtp transport option "hosts_noproxy_tls" to control whether multiple
98 deliveries on a single TCP connection can maintain a TLS connection
99 open. By default disabled for all hosts, doing so saves the cost of
100 making new TLS sessions, at the cost of having to proxy the data via
101 another process. Logging is also affected.
103 4. A malware connection type for the FPSCAND protocol.
105 5. An option for recipient verify callouts to hold the connection open for
106 further recipients and for delivery.
108 6. The reproducible build $SOURCE_DATE_EPOCH environment variable is now
111 7. Optionally, an alternate format for spool data-files which matches the
112 wire format - meaning more efficient reception and transmission (at the
113 cost of difficulty with standard Unix tools). Only used for messages
114 received using the ESMTP CHUNKING option, and when a new main-section
115 option "spool_wireformat" (false by default) is set.
117 8. New main configuration option "commandline_checks_require_admin" to
118 restrict who can use various introspection options.
120 9. New option modifier "no_check" for quota and quota_filecount
121 appendfile transport.
123 10. Variable $smtp_command_history returning a comma-sep list of recent
126 11. Millisecond timetamps in logs, on log_selector "millisec". Also affects
127 log elements QT, DT and D, and timstamps in debug output.
129 12. TCP Fast Open logging. As a server, logs when the SMTP banner was sent
130 while still in SYN_RECV state; as a client logs when the connection
131 is opened with a TFO cookie.
133 13. DKIM support for multiple signing, by domain and/or key-selector.
134 DKIM support for multiple hashes, and for alternate-identity tags.
135 Builtin macro with default list of signed headers.
136 Better syntax for specifying oversigning.
137 The DKIM ACL can override verification status, and status is visible in
140 14. Exipick understands -C|--config for an alternative Exim
143 15. TCP Fast Open used, with data-on-SYN, for client SMTP via SOCKS5 proxy,
144 for ${readsocket } expansions, and for ClamAV.
146 16. The "-be" expansion test mode now supports macros. Macros are expanded
147 in test lines, and new macros can be defined.
149 17. Support for server-side dual-certificate-stacks (eg. RSA + ECDSA).
155 1. Allow relative config file names for ".include"
157 2. A main-section config option "debug_store" to control the checks on
158 variable locations during store-reset. Normally false but can be enabled
159 when a memory corrution issue is suspected on a production system.
165 1. The new perl_taintmode option allows to run the embedded perl
166 interpreter in taint mode.
168 2. New log_selector: dnssec, adds a "DS" tag to acceptance and delivery lines.
170 3. Speculative debugging, via a "kill" option to the "control=debug" ACL
173 4. New expansion item ${sha3:<string>} / ${sha3_<N>:<string>}.
174 N can be 224, 256 (default), 384, 512.
175 With GnuTLS 3.5.0 or later, only.
177 5. Facility for named queues: A command-line argument can specify
178 the queue name for a queue operation, and an ACL modifier can set
179 the queue to be used for a message. A $queue_name variable gives
182 6. New expansion operators base32/base32d.
184 7. The CHUNKING ESMTP extension from RFC 3030. May give some slight
185 performance increase and network load decrease. Main config option
186 chunking_advertise_hosts, and smtp transport option hosts_try_chunking
189 8. LMDB lookup support, as Experimental. Patch supplied by Andrew Colin Kissa.
191 9. Expansion operator escape8bit, like escape but not touching newline etc..
193 10. Feature macros, generated from compile options. All start with "_HAVE_"
194 and go on with some roughly recognisable name. Driver macros, for
195 router, transport and authentication drivers; names starting with "_DRIVER_".
196 Option macros, for each configuration-file option; all start with "_OPT_".
197 Use the "-bP macros" command-line option to see what is present.
199 11. Integer values for options can take a "G" multiplier.
201 12. defer=pass option for the ACL control cutthrough_delivery, to reflect 4xx
202 returns from the target back to the initiator, rather than spooling the
205 13. New built-in constants available for tls_dhparam and default changed.
207 14. If built with EXPERIMENTAL_QUEUEFILE, a queuefile transport, for writing
208 out copies of the message spool files for use by 3rd-party scanners.
210 15. A new option on the smtp transport, hosts_try_fastopen. If the system
211 supports it (on Linux it must be enabled in the kernel by the sysadmin)
212 try to use RFC 7413 "TCP Fast Open". No data is sent on the SYN segment
213 but it permits a peer that also supports the facility to send its SMTP
214 banner immediately after the SYN,ACK segment rather then waiting for
215 another ACK - so saving up to one roundtrip time. Because it requires
216 previous communication with the peer (we save a cookie from it) this
217 will only become active on frequently-contacted destinations.
219 16. A new syslog_pid option to suppress PID duplication in syslog lines.
225 1. The ACL conditions regex and mime_regex now capture substrings
226 into numeric variables $regex1 to 9, like the "match" expansion condition.
228 2. New $callout_address variable records the address used for a spam=,
229 malware= or verify= callout.
231 3. Transports now take a "max_parallel" option, to limit concurrency.
233 4. Expansion operators ${ipv6norm:<string>} and ${ipv6denorm:<string>}.
234 The latter expands to a 8-element colon-sep set of hex digits including
235 leading zeroes. A trailing ipv4-style dotted-decimal set is converted
236 to hex. Pure ipv4 addresses are converted to IPv4-mapped IPv6.
237 The former operator strips leading zeroes and collapses the longest
238 set of 0-groups to a double-colon.
240 5. New "-bP config" support, to dump the effective configuration.
242 6. New $dkim_key_length variable.
244 7. New base64d and base64 expansion items (the existing str2b64 being a
245 synonym of the latter). Add support in base64 for certificates.
247 8. New main configuration option "bounce_return_linesize_limit" to
248 avoid oversize bodies in bounces. The default value matches RFC
251 9. New $initial_cwd expansion variable.
257 1. Support for using the system standard CA bundle.
259 2. New expansion items $config_file, $config_dir, containing the file
260 and directory name of the main configuration file. Also $exim_version.
262 3. New "malware=" support for Avast.
264 4. New "spam=" variant option for Rspamd.
266 5. Assorted options on malware= and spam= scanners.
268 6. A command-line option to write a comment into the logfile.
270 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
271 be configured to make connections via socks5 proxies.
273 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
274 the transmission of UTF-8 envelope addresses.
276 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
277 used encoding of Maildir folder names.
279 10. A logging option for slow DNS lookups.
281 11. New ${env {<variable>}} expansion.
283 12. A non-SMTP authenticator using information from TLS client certificates.
285 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
286 Patch originally by Wolfgang Breyha.
288 14. Main option "dns_trust_aa" for trusting your local nameserver at the
289 same level as DNSSEC.
295 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
296 DANE SMTP draft to assess a secure chain of trust of the certificate
297 used to establish the TLS connection based on a TLSA record in the
298 domain of the sender.
300 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
301 and several new events have been created. The reason is because it has
302 been expanded beyond just firing events during the transport phase. Any
303 existing TPDA transport options will have to be rewritten to use a new
304 $event_name expansion variable in a condition. Refer to the
305 experimental-spec.txt for details and examples.
307 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
308 server certs used for TLS match the result of the MX lookup. It does
309 not use the same mechanism as DANE.
319 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
320 configured to expect an initial header from a proxy that will make the
321 actual external source IP:host be used in exim instead of the IP of the
322 proxy that is connecting to it.
324 2. New verify option header_names_ascii, which will check to make sure
325 there are no non-ASCII characters in header names. Exim itself handles
326 those non-ASCII characters, but downstream apps may not, so Exim can
327 detect and reject if those characters are present.
329 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
330 codepoints with valid ones.
332 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
333 command line and matching a regex against the return data for trigger
334 and a second regex to extract malware_name. The mail spoolfile name can
335 be included in the command line.
337 5. The smtp transport now supports options "tls_verify_hosts" and
338 "tls_try_verify_hosts". If either is set the certificate verification
339 is split from the encryption operation. The default remains that a failed
340 verification cancels the encryption.
342 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
343 lookup can now set a list of servers to use that is different from the
346 7. New command-line option -C for exiqgrep to specify alternate exim.conf
347 file when searching the queue.
349 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
351 9. Support for DNSSEC on outbound connections.
353 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
354 "certextract" to extract fields from them. Hash operators md5 and sha1
355 work over them for generating fingerprints, and a new sha256 operator
358 11. PRDR is now supported dy default.
360 12. OCSP stapling is now supported by default.
362 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
363 Delivery Status Notification messages in MIME format, and negotiate
364 DSN features per RFC 3461.
370 1. New command-line option -bI:sieve will list all supported sieve extensions
371 of this Exim build on standard output, one per line.
372 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
373 query this to establish the correct list to include in the protocol's
374 SIEVE capability line.
376 2. If the -n option is combined with the -bP option, then the name of an
377 emitted option is not output, only the value (if visible to you).
378 For instance, "exim -n -bP pid_file_path" should just emit a pathname
379 followed by a newline, and no other text.
381 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
382 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
383 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
384 acceptable for security. (Option accepted but ignored if using OpenSSL).
385 Defaults to 1024, the old value. May be lowered only to 512, or raised as
386 far as you like. Raising this may hinder TLS interoperability with other
387 sites and is not currently recommended. Lowering this will permit you to
388 establish a TLS session which is not as secure as you might like.
390 Unless you really know what you are doing, leave it alone.
392 4. If not built with DISABLE_DNSSEC, Exim now has the main option
393 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
394 to send the DO flag to your recursive resolver. If you have a recursive
395 resolver, which can set the Authenticated Data (AD) flag in results, Exim
396 can now detect this. Exim does not perform validation itself, instead
397 relying upon a trusted path to the resolver.
399 Current status: work-in-progress; $sender_host_dnssec variable added.
401 5. DSCP support for outbound connections: on a transport using the smtp driver,
402 set "dscp = ef", for instance, to cause the connections to have the relevant
403 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
405 Similarly for inbound connections, there is a new control modifier, dscp,
406 so "warn control = dscp/ef" in the connect ACL, or after authentication.
408 Supported values depend upon system libraries. "exim -bI:dscp" to list the
409 ones Exim knows of. You can also set a raw number 0..0x3F.
411 6. The -G command-line flag is no longer ignored; it is now equivalent to an
412 ACL setting "control = suppress_local_fixups". The -L command-line flag
413 is now accepted and forces use of syslog, with the provided tag as the
414 process name. A few other flags used by Sendmail are now accepted and
417 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
418 ACL modifier; works for single-recipient mails which are received on and
419 deliverable via SMTP. Using the connection made for a recipient verify,
420 if requested before the verify, or a new one made for the purpose while
421 the inbound connection is still active. The bulk of the mail item is copied
422 direct from the inbound socket to the outbound (as well as the spool file).
423 When the source notifies the end of data, the data acceptance by the destination
424 is negotiated before the acceptance is sent to the source. If the destination
425 does not accept the mail item, for example due to content-scanning, the item
426 is not accepted from the source and therefore there is no need to generate
427 a bounce mail. This is of benefit when providing a secondary-MX service.
428 The downside is that delays are under the control of the ultimate destination
431 The Received-by: header on items delivered by cutthrough is generated
432 early in reception rather than at the end; this will affect any timestamp
433 included. The log line showing delivery is recorded before that showing
434 reception; it uses a new ">>" tag instead of "=>".
436 To support the feature, verify-callout connections can now use ESMTP and TLS.
437 The usual smtp transport options are honoured, plus a (new, default everything)
438 hosts_verify_avoid_tls.
440 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
441 for specific access to the information for each connection. The old names
442 are present for now but deprecated.
444 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
446 8. New expansion operators ${listnamed:name} to get the content of a named list
447 and ${listcount:string} to count the items in a list.
449 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
450 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
451 modules. For some situations this is desirable, but we expect admin in
452 those situations to know they want the feature. More commonly, it means
453 that GUI user modules get loaded and are broken by the setuid Exim being
454 unable to access files specified in environment variables and passed
455 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
456 unless this new option is set.
458 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
459 so have also added a build option which can be used to build Exim with GnuTLS
460 but without trying to use any kind of PKCS11 support. Uncomment this in the
463 AVOID_GNUTLS_PKCS11=yes
465 10. The "acl = name" condition on an ACL now supports optional arguments.
466 New expansion item "${acl {name}{arg}...}" and expansion condition
467 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
468 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
469 Variable $acl_narg contains the number of arguments. If the ACL sets
470 a "message =" value this becomes the result of the expansion item,
471 or the value of $value for the expansion condition. If the ACL returns
472 accept the expansion condition is true; if reject, false. A defer
473 return results in a forced fail.
475 11. Routers and transports can now have multiple headers_add and headers_remove
476 option lines. The concatenated list is used.
478 12. New ACL modifier "remove_header" can remove headers before message gets
479 handled by routers/transports.
481 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
482 "aaaa" and "a" lookups is done and the full set of results returned.
484 14. New expansion variable $headers_added with content from ACL add_header
485 modifier (but not yet added to message).
487 15. New 8bitmime status logging option for received messages. Log field "M8S".
489 16. New authenticated_sender logging option, adding to log field "A".
491 17. New expansion variables $router_name and $transport_name. Useful
492 particularly for debug_print as -bt command-line option does not
493 require privilege whereas -d does.
495 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
496 proposed extension to SMTP from Eric Hall.
498 19. The pipe transport has gained the force_command option, to allow
499 decorating commands from user .forward pipe aliases with prefix
500 wrappers, for instance.
502 20. Callout connections can now AUTH; the same controls as normal delivery
505 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
506 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
507 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
508 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
509 dmarc_status. It adds new control flags dmarc_disable_verify and
510 dmarc_enable_forensic. The default for the dmarc_tld_file option is
511 "/etc/exim/opendmarc.tlds" and can be changed via EDITME.
513 22. Add expansion variable $authenticated_fail_id, which is the username
514 provided to the authentication method which failed. It is available
515 for use in subsequent ACL processing (typically quit or notquit ACLs).
517 23. New ACL modifier "udpsend" can construct a UDP packet to send to a given
520 24. New ${hexquote:..string..} expansion operator converts non-printable
521 characters in the string to \xNN form.
523 25. Experimental TPDA (Transport Post Delivery Action) function added.
524 Patch provided by Axel Rau.
526 26. Experimental Redis lookup added. Patch provided by Warren Baker.
532 1. New authenticator driver, "gsasl". Server-only (at present).
533 This is a SASL interface, licensed under GPL, which can be found at
534 http://www.gnu.org/software/gsasl/.
535 This system does not provide sources of data for authentication, so
536 careful use needs to be made of the conditions in Exim.
538 2. New authenticator driver, "heimdal_gssapi". Server-only.
539 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
540 is no longer honoured for setuid programs by Heimdal. Use the
541 "server_keytab" option to point to the keytab.
543 3. The "pkg-config" system can now be used when building Exim to reference
544 cflags and library information for lookups and authenticators, rather
545 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
546 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
547 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
549 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
550 find the headers and libraries for PCRE.
552 4. New expansion variable $tls_bits.
554 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
555 be joined together with ASCII NUL characters to construct the key to pass
556 into the DBM library. Can be used with gsasl to access sasldb2 files as
559 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
561 Avoid release 1.0.1a if you can. Note that the default value of
562 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
563 increased susceptibility to attack. This may still have interoperability
564 implications for very old clients (see version 4.31 change 37) but
565 administrators can choose to make the trade-off themselves and restore
566 compatibility at the cost of session security.
568 7. Use of the new expansion variable $tls_sni in the main configuration option
569 tls_certificate will cause Exim to re-expand the option, if the client
570 sends the TLS Server Name Indication extension, to permit choosing a
571 different certificate; tls_privatekey will also be re-expanded. You must
572 still set these options to expand to valid files when $tls_sni is not set.
574 The SMTP Transport has gained the option tls_sni, which will set a hostname
575 for outbound TLS sessions, and set $tls_sni too.
577 A new log_selector, +tls_sni, has been added, to log received SNI values
578 for Exim as a server.
580 8. The existing "accept_8bitmime" option now defaults to true. This means
581 that Exim is deliberately not strictly RFC compliant. We're following
582 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
583 Those who disagree, or know that they are talking to mail servers that,
584 even today, are not 8-bit clean, need to turn off this option.
586 9. Exim can now be started with -bw (with an optional timeout, given as
587 -bw<timespec>). With this, stdin at startup is a socket that is
588 already listening for connections. This has a more modern name of
589 "socket activation", but forcing the activated socket to fd 0. We're
590 interested in adding more support for modern variants.
592 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
593 for numbers indicates multiplication by 1024^3.
595 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
596 gnutls_require_mac & gnutls_require_protocols are no longer supported.
597 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
598 string, documentation for which is at:
599 http://www.gnutls.org/manual/html_node/Priority-Strings.html
601 SNI support has been added to Exim's GnuTLS integration too.
603 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
604 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
606 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
607 is now available. If the contents of the file are valid, then Exim will
608 send that back in response to a TLS status request; this is OCSP Stapling.
609 Exim will not maintain the contents of the file in any way: administrators
610 are responsible for ensuring that it is up-to-date.
612 See "experimental-spec.txt" for more details.
614 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
615 identically to TXT record lookups.
617 14. New expansion variable $tod_epoch_l for higher-precision time.
619 15. New global option tls_dh_max_bits, defaulting to current value of NSS
620 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
621 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
623 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
624 Option can now be a path or an identifier for a standard prime.
625 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
626 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
629 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
630 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
631 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
637 1. New options for the ratelimit ACL condition: /count= and /unique=.
638 The /noupdate option has been replaced by a /readonly option.
640 2. The SMTP transport's protocol option may now be set to "smtps", to
641 use SSL-on-connect outbound.
643 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
644 there is a problem talking to the AV scanner, or the AV scanner running.
646 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
647 and check if the search item is a member of the list. This does not
648 support named lists, but does subject the list part to string expansion.
650 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
651 built, Exim no longer performs string expansion on the second string of
652 the match_* expansion conditions: "match_address", "match_domain",
653 "match_ip" & "match_local_part". Named lists can still be used.
659 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
660 or off in the resolver library.
666 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
667 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
668 libraries. The following global options have been added in support of
669 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
670 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
672 2. The pipe transport now takes a boolean option, "freeze_signal", default
673 false. When true, if the external delivery command exits on a signal then
674 Exim will freeze the message in the queue, instead of generating a bounce.
676 3. Log filenames may now use %M as an escape, instead of %D (still available).
677 The %M pattern expands to yyyymm, providing month-level resolution.
679 4. The $message_linecount variable is now updated for the maildir_tag option,
680 in the same way as $message_size, to reflect the real number of lines,
681 including any header additions or removals from transport.
683 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
684 Exim now selects entries randomly, to better scale in a cluster setup.
690 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
691 the flaw permitted the Exim run-time user to cause root to append to
692 arbitrary files of the attacker's choosing, with the content based
693 on content supplied by the attacker.
695 2. Exim now supports loading some lookup types at run-time, using your
696 platform's dlopen() functionality. This has limited platform support
697 and the intention is not to support every variant, it's limited to
698 dlopen(). This permits the main Exim binary to not be linked against
699 all the libraries needed for all the lookup types.
705 NOTE: this version is not guaranteed backwards-compatible, please read the
706 items below carefully
708 1. A new main configuration option, "openssl_options", is available if Exim
709 is built with SSL support provided by OpenSSL. The option allows
710 administrators to specify OpenSSL options to be used on connections;
711 typically this is to set bug compatibility features which the OpenSSL
712 developers have not enabled by default. There may be security
713 consequences for certain options, so these should not be changed
716 2. A new pipe transport option, "permit_coredumps", may help with problem
717 diagnosis in some scenarios. Note that Exim is typically installed as
718 a setuid binary, which on most OSes will inhibit coredumps by default,
719 so that safety mechanism would have to be overridden for this option to
720 be able to take effect.
722 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
723 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
724 Note that this switches Exim to use a new API ("INSTREAM") and a future
725 release of ClamAV will remove support for the old API ("STREAM").
727 The av_scanner option, when set to "clamd", now takes an optional third
728 part, "local", which causes Exim to pass a filename to ClamAV instead of
729 the file content. This is the same behaviour as when clamd is pointed at
730 a Unix-domain socket. For example:
732 av_scanner = clamd:192.0.2.3 1234:local
734 ClamAV's ExtendedDetectionInfo response format is now handled.
736 4. There is now a -bmalware option, restricted to admin users. This option
737 takes one parameter, a filename, and scans that file with Exim's
738 malware-scanning framework. This is intended purely as a debugging aid
739 to ensure that Exim's scanning is working, not to replace other tools.
740 Note that the ACL framework is not invoked, so if av_scanner references
741 ACL variables without a fallback then this will fail.
743 5. There is a new expansion operator, "reverse_ip", which will reverse IP
744 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
746 ${reverse_ip:192.0.2.4}
748 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
749 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
751 6. There is a new ACL control called "debug", to enable debug logging.
752 This allows selective logging of certain incoming transactions within
753 production environments, with some care. It takes two options, "tag"
754 and "opts"; "tag" is included in the filename of the log and "opts"
755 is used as per the -d<options> command-line option. Examples, which
756 don't all make sense in all contexts:
759 control = debug/tag=.$sender_host_address
760 control = debug/opts=+expand+acl
761 control = debug/tag=.$message_exim_id/opts=+expand
763 7. It has always been implicit in the design and the documentation that
764 "the Exim user" is not root. src/EDITME said that using root was
765 "very strongly discouraged". This is not enough to keep people from
766 shooting themselves in the foot in days when many don't configure Exim
767 themselves but via package build managers. The security consequences of
768 running various bits of network code are severe if there should be bugs in
769 them. As such, the Exim user may no longer be root. If configured
770 statically, Exim will refuse to build. If configured as ref:user then Exim
771 will exit shortly after start-up. If you must shoot yourself in the foot,
772 then henceforth you will have to maintain your own local patches to strip
775 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
776 condition logic to determine truth/failure and will fail to expand many
777 strings, bool_lax{} uses the router condition logic, where most strings
779 Note: bool{00} is false, bool_lax{00} is true.
781 9. Routers now support multiple "condition" tests.
783 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
784 Setting this allows an admin to define which entry in the tcpwrappers
785 config file will be used to control access to the daemon. This option
786 is only available when Exim is built with USE_TCP_WRAPPERS. The
787 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
790 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
791 the Exim run-time user, instead of root.
793 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
794 is forced on. This is mitigated by the new build option
795 TRUSTED_CONFIG_LIST which defines a list of configuration files which
796 are trusted; one per line. If a config file is owned by root and matches
797 a pathname in the list, then it may be invoked by the Exim build-time
798 user without Exim relinquishing root privileges.
800 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
801 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
802 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
803 include the main config. As a transition mechanism, we are temporarily
804 providing a work-around: the new build option WHITELIST_D_MACROS provides
805 a colon-separated list of macro names which may be overridden by the Exim
806 run-time user. The values of these macros are constrained to the regex
807 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
813 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
814 writable, the other to locking of MBX folders (not mbox).
816 2. MySQL stored procedures are now supported.
818 3. The dkim_domain transport option is now a list, not a single string, and
819 messages will be signed for each element in the list (discarding
822 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
823 in the presence of multiple character strings within the RR. Prior to 4.70,
824 only the first string would be returned. The dnsdb lookup now, by default,
825 preserves the pre-4.70 semantics, but also now takes an extended output
826 separator specification. The separator can be followed by a semicolon, to
827 concatenate the individual text strings together with no join character,
828 or by a comma and a second separator character, in which case the text
829 strings within a TXT record are joined on that second character.
830 Administrators are reminded that DNS provides no ordering guarantees
831 between multiple records in an RRset. For example:
833 foo.example. IN TXT "a" "b" "c"
834 foo.example. IN TXT "d" "e" "f"
836 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
837 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
838 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
844 1. Native DKIM support without an external library.
845 (Note that if no action to prevent it is taken, a straight upgrade will
846 result in DKIM verification of all signed incoming emails. See spec
847 for details on conditionally disabling)
849 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
851 3. There is now a bool{} expansion condition which maps certain strings to
852 true/false condition values (most likely of use in conjunction with the
853 and{} expansion operator).
855 4. The $spam_score, $spam_bar and $spam_report variables are now available
858 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
859 options, provided that Exim is invoked by an admin_user.
861 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
862 which increases compatibility with older clients at the cost of decreased
863 security. Don't set this unless you need to support such clients.
865 7. There is a new expansion operator, ${randint:...} which will produce a
866 "random" number less than the supplied integer. This randomness is
867 not guaranteed to be cryptographically strong, but depending upon how
868 Exim was built may be better than the most naive schemes.
870 8. Exim now explicitly ensures that SHA256 is available when linked against
873 9. The transport_filter_timeout option now applies to SMTP transports too.
879 1. Preliminary DKIM support in Experimental.
885 1. The body_linecount and body_zerocount C variables are now exported in the
888 2. When a dnslists lookup succeeds, the key that was looked up is now placed
889 in $dnslist_matched. When the key is an IP address, it is not reversed in
890 this variable (though it is, of course, in the actual lookup). In simple
893 deny dnslists = spamhaus.example
895 the key is also available in another variable (in this case,
896 $sender_host_address). In more complicated cases, however, this is not
897 true. For example, using a data lookup might generate a dnslists lookup
900 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
902 If this condition succeeds, the value in $dnslist_matched might be
903 192.168.6.7 (for example).
905 3. Authenticators now have a client_condition option. When Exim is running as
906 a client, it skips an authenticator whose client_condition expansion yields
907 "0", "no", or "false". This can be used, for example, to skip plain text
908 authenticators when the connection is not encrypted by a setting such as:
910 client_condition = ${if !eq{$tls_cipher}{}}
912 Note that the 4.67 documentation states that $tls_cipher contains the
913 cipher used for incoming messages. In fact, during SMTP delivery, it
914 contains the cipher used for the delivery. The same is true for
917 4. There is now a -Mvc <message-id> option, which outputs a copy of the
918 message to the standard output, in RFC 2822 format. The option can be used
919 only by an admin user.
921 5. There is now a /noupdate option for the ratelimit ACL condition. It
922 computes the rate and checks the limit as normal, but it does not update
923 the saved data. This means that, in relevant ACLs, it is possible to lookup
924 the existence of a specified (or auto-generated) ratelimit key without
925 incrementing the ratelimit counter for that key.
927 In order for this to be useful, another ACL entry must set the rate
928 for the same key somewhere (otherwise it will always be zero).
933 # Read the rate; if it doesn't exist or is below the maximum
935 deny ratelimit = 100 / 5m / strict / noupdate
936 log_message = RATE: $sender_rate / $sender_rate_period \
937 (max $sender_rate_limit)
939 [... some other logic and tests...]
941 warn ratelimit = 100 / 5m / strict / per_cmd
942 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
943 (max $sender_rate_limit)
944 condition = ${if le{$sender_rate}{$sender_rate_limit}}
948 6. The variable $max_received_linelength contains the number of bytes in the
949 longest line that was received as part of the message, not counting the
950 line termination character(s).
952 7. Host lists can now include +ignore_defer and +include_defer, analagous to
953 +ignore_unknown and +include_unknown. These options should be used with
954 care, probably only in non-critical host lists such as whitelists.
956 8. There's a new option called queue_only_load_latch, which defaults true.
957 If set false when queue_only_load is greater than zero, Exim re-evaluates
958 the load for each incoming message in an SMTP session. Otherwise, once one
959 message is queued, the remainder are also.
961 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
962 cases when an SMTP session ends without sending QUIT. However, when Exim
963 itself is is bad trouble, such as being unable to write to its log files,
964 this ACL is not run, because it might try to do things (such as write to
965 log files) that make the situation even worse.
967 Like the QUIT ACL, this new ACL is provided to make it possible to gather
968 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
969 modifier is forbidden in this ACL.
971 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
972 to a string that indicates the reason for the termination of the SMTP
973 connection. The possible values are:
975 acl-drop Another ACL issued a "drop" command
976 bad-commands Too many unknown or non-mail commands
977 command-timeout Timeout while reading SMTP commands
978 connection-lost The SMTP connection has been lost
979 data-timeout Timeout while reading message data
980 local-scan-error The local_scan() function crashed
981 local-scan-timeout The local_scan() function timed out
982 signal-exit SIGTERM or SIGINT
983 synchronization-error SMTP synchronization error
984 tls-failed TLS failed to start
986 In most cases when an SMTP connection is closed without having received
987 QUIT, Exim sends an SMTP response message before actually closing the
988 connection. With the exception of acl-drop, the default message can be
989 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
990 "drop" verb in another ACL, it is the message from the other ACL that is
993 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
994 servers with individual queries. This is done by starting the query with
995 "servers=x:y:z;", where each item in the list may take one of two forms:
997 (1) If it is just a host name, the appropriate global option (mysql_servers
998 or pgsql_servers) is searched for a host of the same name, and the
999 remaining parameters (database, user, password) are taken from there.
1001 (2) If it contains any slashes, it is taken as a complete parameter set.
1003 The list of servers is used in exactly the same was as the global list.
1004 Once a connection to a server has happened and a query has been
1005 successfully executed, processing of the lookup ceases.
1007 This feature is intended for use in master/slave situations where updates
1008 are occurring, and one wants to update a master rather than a slave. If the
1009 masters are in the list for reading, you might have:
1011 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
1013 In an updating lookup, you could then write
1015 ${lookup mysql{servers=master; UPDATE ...}
1017 If, on the other hand, the master is not to be used for reading lookups:
1019 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
1021 you can still update the master by
1023 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
1025 11. The message_body_newlines option (default FALSE, for backwards
1026 compatibility) can be used to control whether newlines are present in
1027 $message_body and $message_body_end. If it is FALSE, they are replaced by
1034 1. There is a new log selector called smtp_no_mail, which is not included in
1035 the default setting. When it is set, a line is written to the main log
1036 whenever an accepted SMTP connection terminates without having issued a
1039 2. When an item in a dnslists list is followed by = and & and a list of IP
1040 addresses, the behaviour was not clear when the lookup returned more than
1041 one IP address. This has been solved by the addition of == and =& for "all"
1042 rather than the default "any" matching.
1044 3. Up till now, the only control over which cipher suites GnuTLS uses has been
1045 for the cipher algorithms. New options have been added to allow some of the
1046 other parameters to be varied.
1048 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
1049 set, Exim compiles a runtime option called disable_fsync.
1051 5. There is a new variable called $smtp_count_at_connection_start.
1053 6. There's a new control called no_pipelining.
1055 7. There are two new variables called $sending_ip_address and $sending_port.
1056 These are set whenever an SMTP connection to another host has been set up.
1058 8. The expansion of the helo_data option in the smtp transport now happens
1059 after the connection to the server has been made.
1061 9. There is a new expansion operator ${rfc2047d: that decodes strings that
1062 are encoded as per RFC 2047.
1064 10. There is a new log selector called "pid", which causes the current process
1065 id to be added to every log line, in square brackets, immediately after the
1068 11. Exim has been modified so that it flushes SMTP output before implementing
1069 a delay in an ACL. It also flushes the output before performing a callout,
1070 as this can take a substantial time. These behaviours can be disabled by
1071 obeying control = no_delay_flush or control = no_callout_flush,
1072 respectively, at some earlier stage of the connection.
1074 12. There are two new expansion conditions that iterate over a list. They are
1075 called forany and forall.
1077 13. There's a new global option called dsn_from that can be used to vary the
1078 contents of From: lines in bounces and other automatically generated
1079 messages ("delivery status notifications" - hence the name of the option).
1081 14. The smtp transport has a new option called hosts_avoid_pipelining.
1083 15. By default, exigrep does case-insensitive matches. There is now a -I option
1084 that makes it case-sensitive.
1086 16. A number of new features ("addresses", "map", "filter", and "reduce") have
1087 been added to string expansions to make it easier to process lists of
1088 items, typically addresses.
1090 17. There's a new ACL modifier called "continue". It does nothing of itself,
1091 and processing of the ACL always continues with the next condition or
1092 modifier. It is provided so that the side effects of expanding its argument
1095 18. It is now possible to use newline and other control characters (those with
1096 values less than 32, plus DEL) as separators in lists.
1098 19. The exigrep utility now has a -v option, which inverts the matching
1101 20. The host_find_failed option in the manualroute router can now be set to
1108 No new features were added to 4.66.
1114 No new features were added to 4.65.
1120 1. ACL variables can now be given arbitrary names, as long as they start with
1121 "acl_c" or "acl_m" (for connection variables and message variables), are at
1122 least six characters long, with the sixth character being either a digit or
1125 2. There is a new ACL modifier called log_reject_target. It makes it possible
1126 to specify which logs are used for messages about ACL rejections.
1128 3. There is a new authenticator called "dovecot". This is an interface to the
1129 authentication facility of the Dovecot POP/IMAP server, which can support a
1130 number of authentication methods.
1132 4. The variable $message_headers_raw provides a concatenation of all the
1133 messages's headers without any decoding. This is in contrast to
1134 $message_headers, which does RFC2047 decoding on the header contents.
1136 5. In a DNS black list, if two domain names, comma-separated, are given, the
1137 second is used first to do an initial check, making use of any IP value
1138 restrictions that are set. If there is a match, the first domain is used,
1139 without any IP value restrictions, to get the TXT record.
1141 6. All authenticators now have a server_condition option.
1143 7. There is a new command-line option called -Mset. It is useful only in
1144 conjunction with -be (that is, when testing string expansions). It must be
1145 followed by a message id; Exim loads the given message from its spool
1146 before doing the expansions.
1148 8. Another similar new command-line option is called -bem. It operates like
1149 -be except that it must be followed by the name of a file that contains a
1152 9. When an address is delayed because of a 4xx response to a RCPT command, it
1153 is now the combination of sender and recipient that is delayed in
1154 subsequent queue runs until its retry time is reached.
1156 10. Unary negation and the bitwise logical operators and, or, xor, not, and
1157 shift, have been added to the eval: and eval10: expansion items.
1159 11. The variables $interface_address and $interface_port have been renamed
1160 as $received_ip_address and $received_port, to make it clear that they
1161 relate to message reception rather than delivery. (The old names remain
1162 available for compatibility.)
1164 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
1165 to vary the message that is sent when an SMTP command is accepted.
1171 1. There is a new Boolean option called filter_prepend_home for the redirect
1174 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
1175 start of receiving a non-SMTP message, before any of the message has been
1178 3. When an SMTP error message is specified in a "message" modifier in an ACL,
1179 or in a :fail: or :defer: message in a redirect router, Exim now checks the
1180 start of the message for an SMTP error code.
1182 4. There is a new parameter for LDAP lookups called "referrals", which takes
1183 one of the settings "follow" (the default) or "nofollow".
1185 5. Version 20070721.2 of exipick now included, offering these new options:
1187 After all other sorting options have bee processed, reverse order
1188 before displaying messages (-R is synonym).
1190 Randomize order of matching messages before displaying.
1192 Instead of displaying the matching messages, display the sum
1194 --sort <variable>[,<variable>...]
1195 Before displaying matching messages, sort the messages according to
1196 each messages value for each variable.
1198 Negate the value for every test (returns inverse output from the
1199 same criteria without --not).
1205 1. The ${readsocket expansion item now supports Internet domain sockets as well
1206 as Unix domain sockets. If the first argument begins "inet:", it must be of
1207 the form "inet:host:port". The port is mandatory; it may be a number or the
1208 name of a TCP port in /etc/services. The host may be a name, or it may be an
1209 IP address. An ip address may optionally be enclosed in square brackets.
1210 This is best for IPv6 addresses. For example:
1212 ${readsocket{inet:[::1]:1234}{<request data>}...
1214 Only a single host name may be given, but if looking it up yield more than
1215 one IP address, they are each tried in turn until a connection is made. Once
1216 a connection has been made, the behaviour is as for ${readsocket with a Unix
1219 2. If a redirect router sets up file or pipe deliveries for more than one
1220 incoming address, and the relevant transport has batch_max set greater than
1221 one, a batch delivery now occurs.
1223 3. The appendfile transport has a new option called maildirfolder_create_regex.
1224 Its value is a regular expression. For a maildir delivery, this is matched
1225 against the maildir directory; if it matches, Exim ensures that a
1226 maildirfolder file is created alongside the new, cur, and tmp directories.
1232 The documentation is up-to-date for the 4.61 release. Major new features since
1233 the 4.60 release are:
1235 . An option called disable_ipv6, to disable the use of IPv6 completely.
1237 . An increase in the number of ACL variables to 20 of each type.
1239 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
1240 $2, $3, (though those are still set) because the numeric variables get used
1241 for other things in complicated expansions.
1243 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1245 . It is possible to use setclassresources() on some BSD OS to control the
1246 resources used in pipe deliveries.
1248 . A new ACL modifier called add_header, which can be used with any verb.
1250 . More errors are detectable in retry rules.
1252 There are a number of other additions too.
1258 The documentation is up-to-date for the 4.60 release. Major new features since
1259 the 4.50 release are:
1261 . Support for SQLite.
1263 . Support for IGNOREQUOTA in LMTP.
1265 . Extensions to the "submission mode" features.
1267 . Support for Client SMTP Authorization (CSA).
1269 . Support for ratelimiting hosts and users.
1271 . New expansion items to help with the BATV "prvs" scheme.
1273 . A "match_ip" condition, that matches an IP address against a list.
1275 There are many more minor changes.
git://git.exim.org / users / heiko / exim.git / blob