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 CVS before the documentation is updated. Once
7 the documentation is updated, this file is reduced to a short list.
12 1. The new perl_tainmode option allows to run the embedded perl
13 interpreter in taint mode.
15 2. Facility for named queues. A commandline argument can specify
16 the queue name for a queue-runner.
22 1. The ACL conditions regex and mime_regex now capture substrings
23 into numeric variables $regex1 to 9, like the "match" expansion condition.
25 2. New $callout_address variable records the address used for a spam=,
26 malware= or verify= callout.
28 3. Transports now take a "max_parallel" option, to limit concurrency.
30 4. Expansion operators ${ipv6norm:<string>} and ${ipv6denorm:<string>}.
31 The latter expands to a 8-element colon-sep set of hex digits including
32 leading zeroes. A trailing ipv4-style dotted-decimal set is converted
33 to hex. Pure ipv4 addresses are converted to IPv4-mapped IPv6.
34 The former operator strips leading zeroes and collapses the longest
35 set of 0-groups to a double-colon.
37 5. New "-bP config" support, to dump the effective configuration.
39 6. New $dkim_key_length variable.
41 7. New base64d and base64 expansion items (the existing str2b64 being a
42 synonym of the latter). Add support in base64 for certificates.
44 8. New main configuration option "bounce_return_linesize_limit" to
45 avoid oversize bodies in bounces. The dafault value matches RFC
48 9. New $initial_cwd expansion variable.
54 1. Support for using the system standard CA bundle.
56 2. New expansion items $config_file, $config_dir, containing the file
57 and directory name of the main configuration file. Also $exim_version.
59 3. New "malware=" support for Avast.
61 4. New "spam=" variant option for Rspamd.
63 5. Assorted options on malware= and spam= scanners.
65 6. A commandline option to write a comment into the logfile.
67 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
68 be configured to make connections via socks5 proxies.
70 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
71 the transmission of UTF-8 envelope addresses.
73 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
74 used encoding of Maildir folder names.
76 10. A logging option for slow DNS lookups.
78 11. New ${env {<variable>}} expansion.
80 12. A non-SMTP authenticator using information from TLS client certificates.
82 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
83 Patch originally by Wolfgang Breyha.
85 14. Main option "dns_trust_aa" for trusting your local nameserver at the
92 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
93 DANE smtp draft to assess a secure chain of trust of the certificate
94 used to establish the TLS connection based on a TLSA record in the
97 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
98 and several new events have been created. The reason is because it has
99 been expanded beyond just firing events during the transport phase. Any
100 existing TPDA transport options will have to be rewritten to use a new
101 $event_name expansion variable in a condition. Refer to the
102 experimental-spec.txt for details and examples.
104 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
105 server certs used for TLS match the result of the MX lookup. It does
106 not use the same mechanism as DANE.
116 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
117 configured to expect an initial header from a proxy that will make the
118 actual external source IP:host be used in exim instead of the IP of the
119 proxy that is connecting to it.
121 2. New verify option header_names_ascii, which will check to make sure
122 there are no non-ASCII characters in header names. Exim itself handles
123 those non-ASCII characters, but downstream apps may not, so Exim can
124 detect and reject if those characters are present.
126 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
127 codepoints with valid ones.
129 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
130 command line and matching a regex against the return data for trigger
131 and a second regex to extract malware_name. The mail spoolfile name can
132 be included in the command line.
134 5. The smtp transport now supports options "tls_verify_hosts" and
135 "tls_try_verify_hosts". If either is set the certificate verification
136 is split from the encryption operation. The default remains that a failed
137 verification cancels the encryption.
139 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
140 lookup can now set a list of servers to use that is different from the
143 7. New command-line option -C for exiqgrep to specify alternate exim.conf
144 file when searching the queue.
146 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
148 9. Support for DNSSEC on outbound connections.
150 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
151 "certextract" to extract fields from them. Hash operators md5 and sha1
152 work over them for generating fingerprints, and a new sha256 operator
155 11. PRDR is now supported dy default.
157 12. OCSP stapling is now supported by default.
159 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
160 Delivery Status Notification messages in MIME format, and negociate
161 DSN features per RFC 3461.
167 1. New command-line option -bI:sieve will list all supported sieve extensions
168 of this Exim build on standard output, one per line.
169 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
170 query this to establish the correct list to include in the protocol's
171 SIEVE capability line.
173 2. If the -n option is combined with the -bP option, then the name of an
174 emitted option is not output, only the value (if visible to you).
175 For instance, "exim -n -bP pid_file_path" should just emit a pathname
176 followed by a newline, and no other text.
178 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
179 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
180 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
181 acceptable for security. (Option accepted but ignored if using OpenSSL).
182 Defaults to 1024, the old value. May be lowered only to 512, or raised as
183 far as you like. Raising this may hinder TLS interoperability with other
184 sites and is not currently recommended. Lowering this will permit you to
185 establish a TLS session which is not as secure as you might like.
187 Unless you really know what you are doing, leave it alone.
189 4. If not built with DISABLE_DNSSEC, Exim now has the main option
190 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
191 to send the DO flag to your recursive resolver. If you have a recursive
192 resolver, which can set the Authenticated Data (AD) flag in results, Exim
193 can now detect this. Exim does not perform validation itself, instead
194 relying upon a trusted path to the resolver.
196 Current status: work-in-progress; $sender_host_dnssec variable added.
198 5. DSCP support for outbound connections: on a transport using the smtp driver,
199 set "dscp = ef", for instance, to cause the connections to have the relevant
200 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
202 Similarly for inbound connections, there is a new control modifier, dscp,
203 so "warn control = dscp/ef" in the connect ACL, or after authentication.
205 Supported values depend upon system libraries. "exim -bI:dscp" to list the
206 ones Exim knows of. You can also set a raw number 0..0x3F.
208 6. The -G command-line flag is no longer ignored; it is now equivalent to an
209 ACL setting "control = suppress_local_fixups". The -L command-line flag
210 is now accepted and forces use of syslog, with the provided tag as the
211 process name. A few other flags used by Sendmail are now accepted and
214 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
215 ACL modifier; works for single-recipient mails which are recieved on and
216 deliverable via SMTP. Using the connection made for a recipient verify,
217 if requested before the verify, or a new one made for the purpose while
218 the inbound connection is still active. The bulk of the mail item is copied
219 direct from the inbound socket to the outbound (as well as the spool file).
220 When the source notifies the end of data, the data acceptance by the destination
221 is negociated before the acceptance is sent to the source. If the destination
222 does not accept the mail item, for example due to content-scanning, the item
223 is not accepted from the source and therefore there is no need to generate
224 a bounce mail. This is of benefit when providing a secondary-MX service.
225 The downside is that delays are under the control of the ultimate destination
228 The Recieved-by: header on items delivered by cutthrough is generated
229 early in reception rather than at the end; this will affect any timestamp
230 included. The log line showing delivery is recorded before that showing
231 reception; it uses a new ">>" tag instead of "=>".
233 To support the feature, verify-callout connections can now use ESMTP and TLS.
234 The usual smtp transport options are honoured, plus a (new, default everything)
235 hosts_verify_avoid_tls.
237 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
238 for specific access to the information for each connection. The old names
239 are present for now but deprecated.
241 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
243 8. New expansion operators ${listnamed:name} to get the content of a named list
244 and ${listcount:string} to count the items in a list.
246 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
247 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
248 modules. For some situations this is desirable, but we expect admin in
249 those situations to know they want the feature. More commonly, it means
250 that GUI user modules get loaded and are broken by the setuid Exim being
251 unable to access files specified in environment variables and passed
252 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
253 unless this new option is set.
255 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
256 so have also added a build option which can be used to build Exim with GnuTLS
257 but without trying to use any kind of PKCS11 support. Uncomment this in the
260 AVOID_GNUTLS_PKCS11=yes
262 10. The "acl = name" condition on an ACL now supports optional arguments.
263 New expansion item "${acl {name}{arg}...}" and expansion condition
264 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
265 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
266 Variable $acl_narg contains the number of arguments. If the ACL sets
267 a "message =" value this becomes the result of the expansion item,
268 or the value of $value for the expansion condition. If the ACL returns
269 accept the expansion condition is true; if reject, false. A defer
270 return results in a forced fail.
272 11. Routers and transports can now have multiple headers_add and headers_remove
273 option lines. The concatenated list is used.
275 12. New ACL modifier "remove_header" can remove headers before message gets
276 handled by routers/transports.
278 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
279 "aaaa" and "a" lookups is done and the full set of results returned.
281 14. New expansion variable $headers_added with content from ACL add_header
282 modifier (but not yet added to message).
284 15. New 8bitmime status logging option for received messages. Log field "M8S".
286 16. New authenticated_sender logging option, adding to log field "A".
288 17. New expansion variables $router_name and $transport_name. Useful
289 particularly for debug_print as -bt commandline option does not
290 require privilege whereas -d does.
292 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
293 proposed extension to SMTP from Eric Hall.
295 19. The pipe transport has gained the force_command option, to allow
296 decorating commands from user .forward pipe aliases with prefix
297 wrappers, for instance.
299 20. Callout connections can now AUTH; the same controls as normal delivery
302 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
303 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
304 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
305 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
306 dmarc_status. It adds new control flags dmarc_disable_verify and
307 dmarc_enable_forensic.
309 22. Add expansion variable $authenticated_fail_id, which is the username
310 provided to the authentication method which failed. It is available
311 for use in subsequent ACL processing (typically quit or notquit ACLs).
313 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
316 24. New ${hexquote:..string..} expansion operator converts non-printable
317 characters in the string to \xNN form.
319 25. Experimental TPDA (Transport Post Delivery Action) function added.
320 Patch provided by Axel Rau.
322 26. Experimental Redis lookup added. Patch provided by Warren Baker.
328 1. New authenticator driver, "gsasl". Server-only (at present).
329 This is a SASL interface, licensed under GPL, which can be found at
330 http://www.gnu.org/software/gsasl/.
331 This system does not provide sources of data for authentication, so
332 careful use needs to be made of the conditions in Exim.
334 2. New authenticator driver, "heimdal_gssapi". Server-only.
335 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
336 is no longer honoured for setuid programs by Heimdal. Use the
337 "server_keytab" option to point to the keytab.
339 3. The "pkg-config" system can now be used when building Exim to reference
340 cflags and library information for lookups and authenticators, rather
341 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
342 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
343 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
345 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
346 find the headers and libraries for PCRE.
348 4. New expansion variable $tls_bits.
350 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
351 be joined together with ASCII NUL characters to construct the key to pass
352 into the DBM library. Can be used with gsasl to access sasldb2 files as
355 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
357 Avoid release 1.0.1a if you can. Note that the default value of
358 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
359 increased susceptibility to attack. This may still have interoperability
360 implications for very old clients (see version 4.31 change 37) but
361 administrators can choose to make the trade-off themselves and restore
362 compatibility at the cost of session security.
364 7. Use of the new expansion variable $tls_sni in the main configuration option
365 tls_certificate will cause Exim to re-expand the option, if the client
366 sends the TLS Server Name Indication extension, to permit choosing a
367 different certificate; tls_privatekey will also be re-expanded. You must
368 still set these options to expand to valid files when $tls_sni is not set.
370 The SMTP Transport has gained the option tls_sni, which will set a hostname
371 for outbound TLS sessions, and set $tls_sni too.
373 A new log_selector, +tls_sni, has been added, to log received SNI values
374 for Exim as a server.
376 8. The existing "accept_8bitmime" option now defaults to true. This means
377 that Exim is deliberately not strictly RFC compliant. We're following
378 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
379 Those who disagree, or know that they are talking to mail servers that,
380 even today, are not 8-bit clean, need to turn off this option.
382 9. Exim can now be started with -bw (with an optional timeout, given as
383 -bw<timespec>). With this, stdin at startup is a socket that is
384 already listening for connections. This has a more modern name of
385 "socket activation", but forcing the activated socket to fd 0. We're
386 interested in adding more support for modern variants.
388 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
389 for numbers indicates multiplication by 1024^3.
391 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
392 gnutls_require_mac & gnutls_require_protocols are no longer supported.
393 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
394 string, documentation for which is at:
395 http://www.gnutls.org/manual/html_node/Priority-Strings.html
397 SNI support has been added to Exim's GnuTLS integration too.
399 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
400 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
402 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
403 is now available. If the contents of the file are valid, then Exim will
404 send that back in response to a TLS status request; this is OCSP Stapling.
405 Exim will not maintain the contents of the file in any way: administrators
406 are responsible for ensuring that it is up-to-date.
408 See "experimental-spec.txt" for more details.
410 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
411 identically to TXT record lookups.
413 14. New expansion variable $tod_epoch_l for higher-precision time.
415 15. New global option tls_dh_max_bits, defaulting to current value of NSS
416 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
417 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
419 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
420 Option can now be a path or an identifier for a standard prime.
421 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
422 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
425 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
426 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
427 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
433 1. New options for the ratelimit ACL condition: /count= and /unique=.
434 The /noupdate option has been replaced by a /readonly option.
436 2. The SMTP transport's protocol option may now be set to "smtps", to
437 use SSL-on-connect outbound.
439 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
440 there is a problem talking to the AV scanner, or the AV scanner running.
442 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
443 and check if the search item is a member of the list. This does not
444 support named lists, but does subject the list part to string expansion.
446 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
447 built, Exim no longer performs string expansion on the second string of
448 the match_* expansion conditions: "match_address", "match_domain",
449 "match_ip" & "match_local_part". Named lists can still be used.
455 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
456 or off in the resolver library.
462 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
463 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
464 libraries. The following global options have been added in support of
465 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
466 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
468 2. The pipe transport now takes a boolean option, "freeze_signal", default
469 false. When true, if the external delivery command exits on a signal then
470 Exim will freeze the message in the queue, instead of generating a bounce.
472 3. Log filenames may now use %M as an escape, instead of %D (still available).
473 The %M pattern expands to yyyymm, providing month-level resolution.
475 4. The $message_linecount variable is now updated for the maildir_tag option,
476 in the same way as $message_size, to reflect the real number of lines,
477 including any header additions or removals from transport.
479 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
480 Exim now selects entries randomly, to better scale in a cluster setup.
486 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
487 the flaw permitted the Exim run-time user to cause root to append to
488 arbitrary files of the attacker's choosing, with the content based
489 on content supplied by the attacker.
491 2. Exim now supports loading some lookup types at run-time, using your
492 platform's dlopen() functionality. This has limited platform support
493 and the intention is not to support every variant, it's limited to
494 dlopen(). This permits the main Exim binary to not be linked against
495 all the libraries needed for all the lookup types.
501 NOTE: this version is not guaranteed backwards-compatible, please read the
502 items below carefully
504 1. A new main configuration option, "openssl_options", is available if Exim
505 is built with SSL support provided by OpenSSL. The option allows
506 administrators to specify OpenSSL options to be used on connections;
507 typically this is to set bug compatibility features which the OpenSSL
508 developers have not enabled by default. There may be security
509 consequences for certain options, so these should not be changed
512 2. A new pipe transport option, "permit_coredumps", may help with problem
513 diagnosis in some scenarios. Note that Exim is typically installed as
514 a setuid binary, which on most OSes will inhibit coredumps by default,
515 so that safety mechanism would have to be overridden for this option to
516 be able to take effect.
518 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
519 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
520 Note that this switches Exim to use a new API ("INSTREAM") and a future
521 release of ClamAV will remove support for the old API ("STREAM").
523 The av_scanner option, when set to "clamd", now takes an optional third
524 part, "local", which causes Exim to pass a filename to ClamAV instead of
525 the file content. This is the same behaviour as when clamd is pointed at
526 a Unix-domain socket. For example:
528 av_scanner = clamd:192.0.2.3 1234:local
530 ClamAV's ExtendedDetectionInfo response format is now handled.
532 4. There is now a -bmalware option, restricted to admin users. This option
533 takes one parameter, a filename, and scans that file with Exim's
534 malware-scanning framework. This is intended purely as a debugging aid
535 to ensure that Exim's scanning is working, not to replace other tools.
536 Note that the ACL framework is not invoked, so if av_scanner references
537 ACL variables without a fallback then this will fail.
539 5. There is a new expansion operator, "reverse_ip", which will reverse IP
540 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
542 ${reverse_ip:192.0.2.4}
544 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
545 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
547 6. There is a new ACL control called "debug", to enable debug logging.
548 This allows selective logging of certain incoming transactions within
549 production environments, with some care. It takes two options, "tag"
550 and "opts"; "tag" is included in the filename of the log and "opts"
551 is used as per the -d<options> command-line option. Examples, which
552 don't all make sense in all contexts:
555 control = debug/tag=.$sender_host_address
556 control = debug/opts=+expand+acl
557 control = debug/tag=.$message_exim_id/opts=+expand
559 7. It has always been implicit in the design and the documentation that
560 "the Exim user" is not root. src/EDITME said that using root was
561 "very strongly discouraged". This is not enough to keep people from
562 shooting themselves in the foot in days when many don't configure Exim
563 themselves but via package build managers. The security consequences of
564 running various bits of network code are severe if there should be bugs in
565 them. As such, the Exim user may no longer be root. If configured
566 statically, Exim will refuse to build. If configured as ref:user then Exim
567 will exit shortly after start-up. If you must shoot yourself in the foot,
568 then henceforth you will have to maintain your own local patches to strip
571 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
572 condition logic to determine truth/failure and will fail to expand many
573 strings, bool_lax{} uses the router condition logic, where most strings
575 Note: bool{00} is false, bool_lax{00} is true.
577 9. Routers now support multiple "condition" tests.
579 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
580 Setting this allows an admin to define which entry in the tcpwrappers
581 config file will be used to control access to the daemon. This option
582 is only available when Exim is built with USE_TCP_WRAPPERS. The
583 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
586 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
587 the Exim run-time user, instead of root.
589 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
590 is forced on. This is mitigated by the new build option
591 TRUSTED_CONFIG_LIST which defines a list of configuration files which
592 are trusted; one per line. If a config file is owned by root and matches
593 a pathname in the list, then it may be invoked by the Exim build-time
594 user without Exim relinquishing root privileges.
596 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
597 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
598 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
599 include the main config. As a transition mechanism, we are temporarily
600 providing a work-around: the new build option WHITELIST_D_MACROS provides
601 a colon-separated list of macro names which may be overridden by the Exim
602 run-time user. The values of these macros are constrained to the regex
603 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
609 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
610 writable, the other to locking of MBX folders (not mbox).
612 2. MySQL stored procedures are now supported.
614 3. The dkim_domain transport option is now a list, not a single string, and
615 messages will be signed for each element in the list (discarding
618 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
619 in the presence of multiple character strings within the RR. Prior to 4.70,
620 only the first string would be returned. The dnsdb lookup now, by default,
621 preserves the pre-4.70 semantics, but also now takes an extended output
622 separator specification. The separator can be followed by a semicolon, to
623 concatenate the individual text strings together with no join character,
624 or by a comma and a second separator character, in which case the text
625 strings within a TXT record are joined on that second character.
626 Administrators are reminded that DNS provides no ordering guarantees
627 between multiple records in an RRset. For example:
629 foo.example. IN TXT "a" "b" "c"
630 foo.example. IN TXT "d" "e" "f"
632 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
633 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
634 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
640 1. Native DKIM support without an external library.
641 (Note that if no action to prevent it is taken, a straight upgrade will
642 result in DKIM verification of all signed incoming emails. See spec
643 for details on conditionally disabling)
645 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
647 3. There is now a bool{} expansion condition which maps certain strings to
648 true/false condition values (most likely of use in conjunction with the
649 and{} expansion operator).
651 4. The $spam_score, $spam_bar and $spam_report variables are now available
654 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
655 options, provided that Exim is invoked by an admin_user.
657 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
658 which increases compatibility with older clients at the cost of decreased
659 security. Don't set this unless you need to support such clients.
661 7. There is a new expansion operator, ${randint:...} which will produce a
662 "random" number less than the supplied integer. This randomness is
663 not guaranteed to be cryptographically strong, but depending upon how
664 Exim was built may be better than the most naive schemes.
666 8. Exim now explicitly ensures that SHA256 is available when linked against
669 9. The transport_filter_timeout option now applies to SMTP transports too.
675 1. Preliminary DKIM support in Experimental.
681 1. The body_linecount and body_zerocount C variables are now exported in the
684 2. When a dnslists lookup succeeds, the key that was looked up is now placed
685 in $dnslist_matched. When the key is an IP address, it is not reversed in
686 this variable (though it is, of course, in the actual lookup). In simple
689 deny dnslists = spamhaus.example
691 the key is also available in another variable (in this case,
692 $sender_host_address). In more complicated cases, however, this is not
693 true. For example, using a data lookup might generate a dnslists lookup
696 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
698 If this condition succeeds, the value in $dnslist_matched might be
699 192.168.6.7 (for example).
701 3. Authenticators now have a client_condition option. When Exim is running as
702 a client, it skips an authenticator whose client_condition expansion yields
703 "0", "no", or "false". This can be used, for example, to skip plain text
704 authenticators when the connection is not encrypted by a setting such as:
706 client_condition = ${if !eq{$tls_cipher}{}}
708 Note that the 4.67 documentation states that $tls_cipher contains the
709 cipher used for incoming messages. In fact, during SMTP delivery, it
710 contains the cipher used for the delivery. The same is true for
713 4. There is now a -Mvc <message-id> option, which outputs a copy of the
714 message to the standard output, in RFC 2822 format. The option can be used
715 only by an admin user.
717 5. There is now a /noupdate option for the ratelimit ACL condition. It
718 computes the rate and checks the limit as normal, but it does not update
719 the saved data. This means that, in relevant ACLs, it is possible to lookup
720 the existence of a specified (or auto-generated) ratelimit key without
721 incrementing the ratelimit counter for that key.
723 In order for this to be useful, another ACL entry must set the rate
724 for the same key somewhere (otherwise it will always be zero).
729 # Read the rate; if it doesn't exist or is below the maximum
731 deny ratelimit = 100 / 5m / strict / noupdate
732 log_message = RATE: $sender_rate / $sender_rate_period \
733 (max $sender_rate_limit)
735 [... some other logic and tests...]
737 warn ratelimit = 100 / 5m / strict / per_cmd
738 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
739 (max $sender_rate_limit)
740 condition = ${if le{$sender_rate}{$sender_rate_limit}}
744 6. The variable $max_received_linelength contains the number of bytes in the
745 longest line that was received as part of the message, not counting the
746 line termination character(s).
748 7. Host lists can now include +ignore_defer and +include_defer, analagous to
749 +ignore_unknown and +include_unknown. These options should be used with
750 care, probably only in non-critical host lists such as whitelists.
752 8. There's a new option called queue_only_load_latch, which defaults true.
753 If set false when queue_only_load is greater than zero, Exim re-evaluates
754 the load for each incoming message in an SMTP session. Otherwise, once one
755 message is queued, the remainder are also.
757 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
758 cases when an SMTP session ends without sending QUIT. However, when Exim
759 itself is is bad trouble, such as being unable to write to its log files,
760 this ACL is not run, because it might try to do things (such as write to
761 log files) that make the situation even worse.
763 Like the QUIT ACL, this new ACL is provided to make it possible to gather
764 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
765 modifier is forbidden in this ACL.
767 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
768 to a string that indicates the reason for the termination of the SMTP
769 connection. The possible values are:
771 acl-drop Another ACL issued a "drop" command
772 bad-commands Too many unknown or non-mail commands
773 command-timeout Timeout while reading SMTP commands
774 connection-lost The SMTP connection has been lost
775 data-timeout Timeout while reading message data
776 local-scan-error The local_scan() function crashed
777 local-scan-timeout The local_scan() function timed out
778 signal-exit SIGTERM or SIGINT
779 synchronization-error SMTP synchronization error
780 tls-failed TLS failed to start
782 In most cases when an SMTP connection is closed without having received
783 QUIT, Exim sends an SMTP response message before actually closing the
784 connection. With the exception of acl-drop, the default message can be
785 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
786 "drop" verb in another ACL, it is the message from the other ACL that is
789 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
790 servers with individual queries. This is done by starting the query with
791 "servers=x:y:z;", where each item in the list may take one of two forms:
793 (1) If it is just a host name, the appropriate global option (mysql_servers
794 or pgsql_servers) is searched for a host of the same name, and the
795 remaining parameters (database, user, password) are taken from there.
797 (2) If it contains any slashes, it is taken as a complete parameter set.
799 The list of servers is used in exactly the same was as the global list.
800 Once a connection to a server has happened and a query has been
801 successfully executed, processing of the lookup ceases.
803 This feature is intended for use in master/slave situations where updates
804 are occurring, and one wants to update a master rather than a slave. If the
805 masters are in the list for reading, you might have:
807 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
809 In an updating lookup, you could then write
811 ${lookup mysql{servers=master; UPDATE ...}
813 If, on the other hand, the master is not to be used for reading lookups:
815 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
817 you can still update the master by
819 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
821 11. The message_body_newlines option (default FALSE, for backwards
822 compatibility) can be used to control whether newlines are present in
823 $message_body and $message_body_end. If it is FALSE, they are replaced by
830 1. There is a new log selector called smtp_no_mail, which is not included in
831 the default setting. When it is set, a line is written to the main log
832 whenever an accepted SMTP connection terminates without having issued a
835 2. When an item in a dnslists list is followed by = and & and a list of IP
836 addresses, the behaviour was not clear when the lookup returned more than
837 one IP address. This has been solved by the addition of == and =& for "all"
838 rather than the default "any" matching.
840 3. Up till now, the only control over which cipher suites GnuTLS uses has been
841 for the cipher algorithms. New options have been added to allow some of the
842 other parameters to be varied.
844 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
845 set, Exim compiles a runtime option called disable_fsync.
847 5. There is a new variable called $smtp_count_at_connection_start.
849 6. There's a new control called no_pipelining.
851 7. There are two new variables called $sending_ip_address and $sending_port.
852 These are set whenever an SMTP connection to another host has been set up.
854 8. The expansion of the helo_data option in the smtp transport now happens
855 after the connection to the server has been made.
857 9. There is a new expansion operator ${rfc2047d: that decodes strings that
858 are encoded as per RFC 2047.
860 10. There is a new log selector called "pid", which causes the current process
861 id to be added to every log line, in square brackets, immediately after the
864 11. Exim has been modified so that it flushes SMTP output before implementing
865 a delay in an ACL. It also flushes the output before performing a callout,
866 as this can take a substantial time. These behaviours can be disabled by
867 obeying control = no_delay_flush or control = no_callout_flush,
868 respectively, at some earlier stage of the connection.
870 12. There are two new expansion conditions that iterate over a list. They are
871 called forany and forall.
873 13. There's a new global option called dsn_from that can be used to vary the
874 contents of From: lines in bounces and other automatically generated
875 messages ("delivery status notifications" - hence the name of the option).
877 14. The smtp transport has a new option called hosts_avoid_pipelining.
879 15. By default, exigrep does case-insensitive matches. There is now a -I option
880 that makes it case-sensitive.
882 16. A number of new features ("addresses", "map", "filter", and "reduce") have
883 been added to string expansions to make it easier to process lists of
884 items, typically addresses.
886 17. There's a new ACL modifier called "continue". It does nothing of itself,
887 and processing of the ACL always continues with the next condition or
888 modifier. It is provided so that the side effects of expanding its argument
891 18. It is now possible to use newline and other control characters (those with
892 values less than 32, plus DEL) as separators in lists.
894 19. The exigrep utility now has a -v option, which inverts the matching
897 20. The host_find_failed option in the manualroute router can now be set to
904 No new features were added to 4.66.
910 No new features were added to 4.65.
916 1. ACL variables can now be given arbitrary names, as long as they start with
917 "acl_c" or "acl_m" (for connection variables and message variables), are at
918 least six characters long, with the sixth character being either a digit or
921 2. There is a new ACL modifier called log_reject_target. It makes it possible
922 to specify which logs are used for messages about ACL rejections.
924 3. There is a new authenticator called "dovecot". This is an interface to the
925 authentication facility of the Dovecot POP/IMAP server, which can support a
926 number of authentication methods.
928 4. The variable $message_headers_raw provides a concatenation of all the
929 messages's headers without any decoding. This is in contrast to
930 $message_headers, which does RFC2047 decoding on the header contents.
932 5. In a DNS black list, if two domain names, comma-separated, are given, the
933 second is used first to do an initial check, making use of any IP value
934 restrictions that are set. If there is a match, the first domain is used,
935 without any IP value restrictions, to get the TXT record.
937 6. All authenticators now have a server_condition option.
939 7. There is a new command-line option called -Mset. It is useful only in
940 conjunction with -be (that is, when testing string expansions). It must be
941 followed by a message id; Exim loads the given message from its spool
942 before doing the expansions.
944 8. Another similar new command-line option is called -bem. It operates like
945 -be except that it must be followed by the name of a file that contains a
948 9. When an address is delayed because of a 4xx response to a RCPT command, it
949 is now the combination of sender and recipient that is delayed in
950 subsequent queue runs until its retry time is reached.
952 10. Unary negation and the bitwise logical operators and, or, xor, not, and
953 shift, have been added to the eval: and eval10: expansion items.
955 11. The variables $interface_address and $interface_port have been renamed
956 as $received_ip_address and $received_port, to make it clear that they
957 relate to message reception rather than delivery. (The old names remain
958 available for compatibility.)
960 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
961 to vary the message that is sent when an SMTP command is accepted.
967 1. There is a new Boolean option called filter_prepend_home for the redirect
970 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
971 start of receiving a non-SMTP message, before any of the message has been
974 3. When an SMTP error message is specified in a "message" modifier in an ACL,
975 or in a :fail: or :defer: message in a redirect router, Exim now checks the
976 start of the message for an SMTP error code.
978 4. There is a new parameter for LDAP lookups called "referrals", which takes
979 one of the settings "follow" (the default) or "nofollow".
981 5. Version 20070721.2 of exipick now included, offering these new options:
983 After all other sorting options have bee processed, reverse order
984 before displaying messages (-R is synonym).
986 Randomize order of matching messages before displaying.
988 Instead of displaying the matching messages, display the sum
990 --sort <variable>[,<variable>...]
991 Before displaying matching messages, sort the messages according to
992 each messages value for each variable.
994 Negate the value for every test (returns inverse output from the
995 same criteria without --not).
1001 1. The ${readsocket expansion item now supports Internet domain sockets as well
1002 as Unix domain sockets. If the first argument begins "inet:", it must be of
1003 the form "inet:host:port". The port is mandatory; it may be a number or the
1004 name of a TCP port in /etc/services. The host may be a name, or it may be an
1005 IP address. An ip address may optionally be enclosed in square brackets.
1006 This is best for IPv6 addresses. For example:
1008 ${readsocket{inet:[::1]:1234}{<request data>}...
1010 Only a single host name may be given, but if looking it up yield more than
1011 one IP address, they are each tried in turn until a connection is made. Once
1012 a connection has been made, the behaviour is as for ${readsocket with a Unix
1015 2. If a redirect router sets up file or pipe deliveries for more than one
1016 incoming address, and the relevant transport has batch_max set greater than
1017 one, a batch delivery now occurs.
1019 3. The appendfile transport has a new option called maildirfolder_create_regex.
1020 Its value is a regular expression. For a maildir delivery, this is matched
1021 against the maildir directory; if it matches, Exim ensures that a
1022 maildirfolder file is created alongside the new, cur, and tmp directories.
1028 The documentation is up-to-date for the 4.61 release. Major new features since
1029 the 4.60 release are:
1031 . An option called disable_ipv6, to disable the use of IPv6 completely.
1033 . An increase in the number of ACL variables to 20 of each type.
1035 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
1036 $2, $3, (though those are still set) because the numeric variables get used
1037 for other things in complicated expansions.
1039 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1041 . It is possible to use setclassresources() on some BSD OS to control the
1042 resources used in pipe deliveries.
1044 . A new ACL modifier called add_header, which can be used with any verb.
1046 . More errors are detectable in retry rules.
1048 There are a number of other additions too.
1054 The documentation is up-to-date for the 4.60 release. Major new features since
1055 the 4.50 release are:
1057 . Support for SQLite.
1059 . Support for IGNOREQUOTA in LMTP.
1061 . Extensions to the "submission mode" features.
1063 . Support for Client SMTP Authorization (CSA).
1065 . Support for ratelimiting hosts and users.
1067 . New expansion items to help with the BATV "prvs" scheme.
1069 . A "match_ip" condition, that matches an IP address against a list.
1071 There are many more minor changes.
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