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 ACL conditions regex and mime_regex now capture substrings
13 into numeric variables $regex1 to 9, like the "match" expansion condition.
15 2. New $callout_address variable records the address used for a spam=,
16 malware= or verify= callout.
18 3. Transports now take a "max_parallel" option, to limit concurrency.
20 4. Expansion operators ${ipv6norm:<string>} and ${ipv6denorm:<string>}.
21 The latter expands to a 8-element colon-sep set of hex digits including
22 leading zeroes. A trailing ipv4-style dotted-decimal set is converted
23 to hex. Pure ipv4 addresses are converted to IPv4-mapped IPv6.
24 The former operator strips leading zeroes and collapses the longest
25 set of 0-groups to a double-colon.
27 5. New "-bP config" support, to dump the effective configuration.
29 6. New $dkim_key_length variable.
31 7. New base64d and base64 expansion items (the existing str2b64 being a
32 synonym of the latter). Add support in base64 for certificates.
34 8. New main configuration option "bounce_return_linesize_limit" to
35 avoid oversize bodies in bounces. The dafault value matches RFC
42 1. Support for using the system standard CA bundle.
44 2. New expansion items $config_file, $config_dir, containing the file
45 and directory name of the main configuration file. Also $exim_version.
47 3. New "malware=" support for Avast.
49 4. New "spam=" variant option for Rspamd.
51 5. Assorted options on malware= and spam= scanners.
53 6. A commandline option to write a comment into the logfile.
55 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
56 be configured to make connections via socks5 proxies.
58 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
59 the transmission of UTF-8 envelope addresses.
61 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
62 used encoding of Maildir folder names.
64 10. A logging option for slow DNS lookups.
66 11. New ${env {<variable>}} expansion.
68 12. A non-SMTP authenticator using information from TLS client certificates.
70 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
71 Patch originally by Wolfgang Breyha.
73 14. Main option "dns_trust_aa" for trusting your local nameserver at the
80 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
81 DANE smtp draft to assess a secure chain of trust of the certificate
82 used to establish the TLS connection based on a TLSA record in the
85 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
86 and several new events have been created. The reason is because it has
87 been expanded beyond just firing events during the transport phase. Any
88 existing TPDA transport options will have to be rewritten to use a new
89 $event_name expansion variable in a condition. Refer to the
90 experimental-spec.txt for details and examples.
92 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
93 server certs used for TLS match the result of the MX lookup. It does
94 not use the same mechanism as DANE.
104 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
105 configured to expect an initial header from a proxy that will make the
106 actual external source IP:host be used in exim instead of the IP of the
107 proxy that is connecting to it.
109 2. New verify option header_names_ascii, which will check to make sure
110 there are no non-ASCII characters in header names. Exim itself handles
111 those non-ASCII characters, but downstream apps may not, so Exim can
112 detect and reject if those characters are present.
114 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
115 codepoints with valid ones.
117 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
118 command line and matching a regex against the return data for trigger
119 and a second regex to extract malware_name. The mail spoolfile name can
120 be included in the command line.
122 5. The smtp transport now supports options "tls_verify_hosts" and
123 "tls_try_verify_hosts". If either is set the certificate verification
124 is split from the encryption operation. The default remains that a failed
125 verification cancels the encryption.
127 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
128 lookup can now set a list of servers to use that is different from the
131 7. New command-line option -C for exiqgrep to specify alternate exim.conf
132 file when searching the queue.
134 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
136 9. Support for DNSSEC on outbound connections.
138 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
139 "certextract" to extract fields from them. Hash operators md5 and sha1
140 work over them for generating fingerprints, and a new sha256 operator
143 11. PRDR is now supported dy default.
145 12. OCSP stapling is now supported by default.
147 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
148 Delivery Status Notification messages in MIME format, and negociate
149 DSN features per RFC 3461.
155 1. New command-line option -bI:sieve will list all supported sieve extensions
156 of this Exim build on standard output, one per line.
157 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
158 query this to establish the correct list to include in the protocol's
159 SIEVE capability line.
161 2. If the -n option is combined with the -bP option, then the name of an
162 emitted option is not output, only the value (if visible to you).
163 For instance, "exim -n -bP pid_file_path" should just emit a pathname
164 followed by a newline, and no other text.
166 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
167 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
168 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
169 acceptable for security. (Option accepted but ignored if using OpenSSL).
170 Defaults to 1024, the old value. May be lowered only to 512, or raised as
171 far as you like. Raising this may hinder TLS interoperability with other
172 sites and is not currently recommended. Lowering this will permit you to
173 establish a TLS session which is not as secure as you might like.
175 Unless you really know what you are doing, leave it alone.
177 4. If not built with DISABLE_DNSSEC, Exim now has the main option
178 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
179 to send the DO flag to your recursive resolver. If you have a recursive
180 resolver, which can set the Authenticated Data (AD) flag in results, Exim
181 can now detect this. Exim does not perform validation itself, instead
182 relying upon a trusted path to the resolver.
184 Current status: work-in-progress; $sender_host_dnssec variable added.
186 5. DSCP support for outbound connections: on a transport using the smtp driver,
187 set "dscp = ef", for instance, to cause the connections to have the relevant
188 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
190 Similarly for inbound connections, there is a new control modifier, dscp,
191 so "warn control = dscp/ef" in the connect ACL, or after authentication.
193 Supported values depend upon system libraries. "exim -bI:dscp" to list the
194 ones Exim knows of. You can also set a raw number 0..0x3F.
196 6. The -G command-line flag is no longer ignored; it is now equivalent to an
197 ACL setting "control = suppress_local_fixups". The -L command-line flag
198 is now accepted and forces use of syslog, with the provided tag as the
199 process name. A few other flags used by Sendmail are now accepted and
202 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
203 ACL modifier; works for single-recipient mails which are recieved on and
204 deliverable via SMTP. Using the connection made for a recipient verify,
205 if requested before the verify, or a new one made for the purpose while
206 the inbound connection is still active. The bulk of the mail item is copied
207 direct from the inbound socket to the outbound (as well as the spool file).
208 When the source notifies the end of data, the data acceptance by the destination
209 is negociated before the acceptance is sent to the source. If the destination
210 does not accept the mail item, for example due to content-scanning, the item
211 is not accepted from the source and therefore there is no need to generate
212 a bounce mail. This is of benefit when providing a secondary-MX service.
213 The downside is that delays are under the control of the ultimate destination
216 The Recieved-by: header on items delivered by cutthrough is generated
217 early in reception rather than at the end; this will affect any timestamp
218 included. The log line showing delivery is recorded before that showing
219 reception; it uses a new ">>" tag instead of "=>".
221 To support the feature, verify-callout connections can now use ESMTP and TLS.
222 The usual smtp transport options are honoured, plus a (new, default everything)
223 hosts_verify_avoid_tls.
225 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
226 for specific access to the information for each connection. The old names
227 are present for now but deprecated.
229 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
231 8. New expansion operators ${listnamed:name} to get the content of a named list
232 and ${listcount:string} to count the items in a list.
234 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
235 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
236 modules. For some situations this is desirable, but we expect admin in
237 those situations to know they want the feature. More commonly, it means
238 that GUI user modules get loaded and are broken by the setuid Exim being
239 unable to access files specified in environment variables and passed
240 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
241 unless this new option is set.
243 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
244 so have also added a build option which can be used to build Exim with GnuTLS
245 but without trying to use any kind of PKCS11 support. Uncomment this in the
248 AVOID_GNUTLS_PKCS11=yes
250 10. The "acl = name" condition on an ACL now supports optional arguments.
251 New expansion item "${acl {name}{arg}...}" and expansion condition
252 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
253 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
254 Variable $acl_narg contains the number of arguments. If the ACL sets
255 a "message =" value this becomes the result of the expansion item,
256 or the value of $value for the expansion condition. If the ACL returns
257 accept the expansion condition is true; if reject, false. A defer
258 return results in a forced fail.
260 11. Routers and transports can now have multiple headers_add and headers_remove
261 option lines. The concatenated list is used.
263 12. New ACL modifier "remove_header" can remove headers before message gets
264 handled by routers/transports.
266 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
267 "aaaa" and "a" lookups is done and the full set of results returned.
269 14. New expansion variable $headers_added with content from ACL add_header
270 modifier (but not yet added to messsage).
272 15. New 8bitmime status logging option for received messages. Log field "M8S".
274 16. New authenticated_sender logging option, adding to log field "A".
276 17. New expansion variables $router_name and $transport_name. Useful
277 particularly for debug_print as -bt commandline option does not
278 require privilege whereas -d does.
280 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
281 proposed extension to SMTP from Eric Hall.
283 19. The pipe transport has gained the force_command option, to allow
284 decorating commands from user .forward pipe aliases with prefix
285 wrappers, for instance.
287 20. Callout connections can now AUTH; the same controls as normal delivery
290 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
291 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
292 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
293 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
294 dmarc_status. It adds new control flags dmarc_disable_verify and
295 dmarc_enable_forensic.
297 22. Add expansion variable $authenticated_fail_id, which is the username
298 provided to the authentication method which failed. It is available
299 for use in subsequent ACL processing (typically quit or notquit ACLs).
301 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
304 24. New ${hexquote:..string..} expansion operator converts non-printable
305 characters in the string to \xNN form.
307 25. Experimental TPDA (Transport Post Delivery Action) function added.
308 Patch provided by Axel Rau.
310 26. Experimental Redis lookup added. Patch provided by Warren Baker.
316 1. New authenticator driver, "gsasl". Server-only (at present).
317 This is a SASL interface, licensed under GPL, which can be found at
318 http://www.gnu.org/software/gsasl/.
319 This system does not provide sources of data for authentication, so
320 careful use needs to be made of the conditions in Exim.
322 2. New authenticator driver, "heimdal_gssapi". Server-only.
323 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
324 is no longer honoured for setuid programs by Heimdal. Use the
325 "server_keytab" option to point to the keytab.
327 3. The "pkg-config" system can now be used when building Exim to reference
328 cflags and library information for lookups and authenticators, rather
329 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
330 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
331 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
333 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
334 find the headers and libraries for PCRE.
336 4. New expansion variable $tls_bits.
338 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
339 be joined together with ASCII NUL characters to construct the key to pass
340 into the DBM library. Can be used with gsasl to access sasldb2 files as
343 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
345 Avoid release 1.0.1a if you can. Note that the default value of
346 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
347 increased susceptibility to attack. This may still have interoperability
348 implications for very old clients (see version 4.31 change 37) but
349 administrators can choose to make the trade-off themselves and restore
350 compatibility at the cost of session security.
352 7. Use of the new expansion variable $tls_sni in the main configuration option
353 tls_certificate will cause Exim to re-expand the option, if the client
354 sends the TLS Server Name Indication extension, to permit choosing a
355 different certificate; tls_privatekey will also be re-expanded. You must
356 still set these options to expand to valid files when $tls_sni is not set.
358 The SMTP Transport has gained the option tls_sni, which will set a hostname
359 for outbound TLS sessions, and set $tls_sni too.
361 A new log_selector, +tls_sni, has been added, to log received SNI values
362 for Exim as a server.
364 8. The existing "accept_8bitmime" option now defaults to true. This means
365 that Exim is deliberately not strictly RFC compliant. We're following
366 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
367 Those who disagree, or know that they are talking to mail servers that,
368 even today, are not 8-bit clean, need to turn off this option.
370 9. Exim can now be started with -bw (with an optional timeout, given as
371 -bw<timespec>). With this, stdin at startup is a socket that is
372 already listening for connections. This has a more modern name of
373 "socket activation", but forcing the activated socket to fd 0. We're
374 interested in adding more support for modern variants.
376 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
377 for numbers indicates multiplication by 1024^3.
379 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
380 gnutls_require_mac & gnutls_require_protocols are no longer supported.
381 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
382 string, documentation for which is at:
383 http://www.gnutls.org/manual/html_node/Priority-Strings.html
385 SNI support has been added to Exim's GnuTLS integration too.
387 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
388 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
390 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
391 is now available. If the contents of the file are valid, then Exim will
392 send that back in response to a TLS status request; this is OCSP Stapling.
393 Exim will not maintain the contents of the file in any way: administrators
394 are responsible for ensuring that it is up-to-date.
396 See "experimental-spec.txt" for more details.
398 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
399 identically to TXT record lookups.
401 14. New expansion variable $tod_epoch_l for higher-precision time.
403 15. New global option tls_dh_max_bits, defaulting to current value of NSS
404 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
405 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
407 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
408 Option can now be a path or an identifier for a standard prime.
409 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
410 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
413 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
414 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
415 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
421 1. New options for the ratelimit ACL condition: /count= and /unique=.
422 The /noupdate option has been replaced by a /readonly option.
424 2. The SMTP transport's protocol option may now be set to "smtps", to
425 use SSL-on-connect outbound.
427 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
428 there is a problem talking to the AV scanner, or the AV scanner running.
430 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
431 and check if the search item is a member of the list. This does not
432 support named lists, but does subject the list part to string expansion.
434 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
435 built, Exim no longer performs string expansion on the second string of
436 the match_* expansion conditions: "match_address", "match_domain",
437 "match_ip" & "match_local_part". Named lists can still be used.
443 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
444 or off in the resolver library.
450 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
451 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
452 libraries. The following global options have been added in support of
453 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
454 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
456 2. The pipe transport now takes a boolean option, "freeze_signal", default
457 false. When true, if the external delivery command exits on a signal then
458 Exim will freeze the message in the queue, instead of generating a bounce.
460 3. Log filenames may now use %M as an escape, instead of %D (still available).
461 The %M pattern expands to yyyymm, providing month-level resolution.
463 4. The $message_linecount variable is now updated for the maildir_tag option,
464 in the same way as $message_size, to reflect the real number of lines,
465 including any header additions or removals from transport.
467 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
468 Exim now selects entries randomly, to better scale in a cluster setup.
474 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
475 the flaw permitted the Exim run-time user to cause root to append to
476 arbitrary files of the attacker's choosing, with the content based
477 on content supplied by the attacker.
479 2. Exim now supports loading some lookup types at run-time, using your
480 platform's dlopen() functionality. This has limited platform support
481 and the intention is not to support every variant, it's limited to
482 dlopen(). This permits the main Exim binary to not be linked against
483 all the libraries needed for all the lookup types.
489 NOTE: this version is not guaranteed backwards-compatible, please read the
490 items below carefully
492 1. A new main configuration option, "openssl_options", is available if Exim
493 is built with SSL support provided by OpenSSL. The option allows
494 administrators to specify OpenSSL options to be used on connections;
495 typically this is to set bug compatibility features which the OpenSSL
496 developers have not enabled by default. There may be security
497 consequences for certain options, so these should not be changed
500 2. A new pipe transport option, "permit_coredumps", may help with problem
501 diagnosis in some scenarios. Note that Exim is typically installed as
502 a setuid binary, which on most OSes will inhibit coredumps by default,
503 so that safety mechanism would have to be overridden for this option to
504 be able to take effect.
506 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
507 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
508 Note that this switches Exim to use a new API ("INSTREAM") and a future
509 release of ClamAV will remove support for the old API ("STREAM").
511 The av_scanner option, when set to "clamd", now takes an optional third
512 part, "local", which causes Exim to pass a filename to ClamAV instead of
513 the file content. This is the same behaviour as when clamd is pointed at
514 a Unix-domain socket. For example:
516 av_scanner = clamd:192.0.2.3 1234:local
518 ClamAV's ExtendedDetectionInfo response format is now handled.
520 4. There is now a -bmalware option, restricted to admin users. This option
521 takes one parameter, a filename, and scans that file with Exim's
522 malware-scanning framework. This is intended purely as a debugging aid
523 to ensure that Exim's scanning is working, not to replace other tools.
524 Note that the ACL framework is not invoked, so if av_scanner references
525 ACL variables without a fallback then this will fail.
527 5. There is a new expansion operator, "reverse_ip", which will reverse IP
528 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
530 ${reverse_ip:192.0.2.4}
532 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
533 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
535 6. There is a new ACL control called "debug", to enable debug logging.
536 This allows selective logging of certain incoming transactions within
537 production environments, with some care. It takes two options, "tag"
538 and "opts"; "tag" is included in the filename of the log and "opts"
539 is used as per the -d<options> command-line option. Examples, which
540 don't all make sense in all contexts:
543 control = debug/tag=.$sender_host_address
544 control = debug/opts=+expand+acl
545 control = debug/tag=.$message_exim_id/opts=+expand
547 7. It has always been implicit in the design and the documentation that
548 "the Exim user" is not root. src/EDITME said that using root was
549 "very strongly discouraged". This is not enough to keep people from
550 shooting themselves in the foot in days when many don't configure Exim
551 themselves but via package build managers. The security consequences of
552 running various bits of network code are severe if there should be bugs in
553 them. As such, the Exim user may no longer be root. If configured
554 statically, Exim will refuse to build. If configured as ref:user then Exim
555 will exit shortly after start-up. If you must shoot yourself in the foot,
556 then henceforth you will have to maintain your own local patches to strip
559 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
560 condition logic to determine truth/failure and will fail to expand many
561 strings, bool_lax{} uses the router condition logic, where most strings
563 Note: bool{00} is false, bool_lax{00} is true.
565 9. Routers now support multiple "condition" tests.
567 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
568 Setting this allows an admin to define which entry in the tcpwrappers
569 config file will be used to control access to the daemon. This option
570 is only available when Exim is built with USE_TCP_WRAPPERS. The
571 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
574 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
575 the Exim run-time user, instead of root.
577 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
578 is forced on. This is mitigated by the new build option
579 TRUSTED_CONFIG_LIST which defines a list of configuration files which
580 are trusted; one per line. If a config file is owned by root and matches
581 a pathname in the list, then it may be invoked by the Exim build-time
582 user without Exim relinquishing root privileges.
584 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
585 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
586 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
587 include the main config. As a transition mechanism, we are temporarily
588 providing a work-around: the new build option WHITELIST_D_MACROS provides
589 a colon-separated list of macro names which may be overridden by the Exim
590 run-time user. The values of these macros are constrained to the regex
591 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
597 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
598 writable, the other to locking of MBX folders (not mbox).
600 2. MySQL stored procedures are now supported.
602 3. The dkim_domain transport option is now a list, not a single string, and
603 messages will be signed for each element in the list (discarding
606 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
607 in the presence of multiple character strings within the RR. Prior to 4.70,
608 only the first string would be returned. The dnsdb lookup now, by default,
609 preserves the pre-4.70 semantics, but also now takes an extended output
610 separator specification. The separator can be followed by a semicolon, to
611 concatenate the individual text strings together with no join character,
612 or by a comma and a second separator character, in which case the text
613 strings within a TXT record are joined on that second character.
614 Administrators are reminded that DNS provides no ordering guarantees
615 between multiple records in an RRset. For example:
617 foo.example. IN TXT "a" "b" "c"
618 foo.example. IN TXT "d" "e" "f"
620 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
621 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
622 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
628 1. Native DKIM support without an external library.
629 (Note that if no action to prevent it is taken, a straight upgrade will
630 result in DKIM verification of all signed incoming emails. See spec
631 for details on conditionally disabling)
633 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
635 3. There is now a bool{} expansion condition which maps certain strings to
636 true/false condition values (most likely of use in conjunction with the
637 and{} expansion operator).
639 4. The $spam_score, $spam_bar and $spam_report variables are now available
642 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
643 options, provided that Exim is invoked by an admin_user.
645 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
646 which increases compatibility with older clients at the cost of decreased
647 security. Don't set this unless you need to support such clients.
649 7. There is a new expansion operator, ${randint:...} which will produce a
650 "random" number less than the supplied integer. This randomness is
651 not guaranteed to be cryptographically strong, but depending upon how
652 Exim was built may be better than the most naive schemes.
654 8. Exim now explicitly ensures that SHA256 is available when linked against
657 9. The transport_filter_timeout option now applies to SMTP transports too.
663 1. Preliminary DKIM support in Experimental.
669 1. The body_linecount and body_zerocount C variables are now exported in the
672 2. When a dnslists lookup succeeds, the key that was looked up is now placed
673 in $dnslist_matched. When the key is an IP address, it is not reversed in
674 this variable (though it is, of course, in the actual lookup). In simple
677 deny dnslists = spamhaus.example
679 the key is also available in another variable (in this case,
680 $sender_host_address). In more complicated cases, however, this is not
681 true. For example, using a data lookup might generate a dnslists lookup
684 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
686 If this condition succeeds, the value in $dnslist_matched might be
687 192.168.6.7 (for example).
689 3. Authenticators now have a client_condition option. When Exim is running as
690 a client, it skips an authenticator whose client_condition expansion yields
691 "0", "no", or "false". This can be used, for example, to skip plain text
692 authenticators when the connection is not encrypted by a setting such as:
694 client_condition = ${if !eq{$tls_cipher}{}}
696 Note that the 4.67 documentation states that $tls_cipher contains the
697 cipher used for incoming messages. In fact, during SMTP delivery, it
698 contains the cipher used for the delivery. The same is true for
701 4. There is now a -Mvc <message-id> option, which outputs a copy of the
702 message to the standard output, in RFC 2822 format. The option can be used
703 only by an admin user.
705 5. There is now a /noupdate option for the ratelimit ACL condition. It
706 computes the rate and checks the limit as normal, but it does not update
707 the saved data. This means that, in relevant ACLs, it is possible to lookup
708 the existence of a specified (or auto-generated) ratelimit key without
709 incrementing the ratelimit counter for that key.
711 In order for this to be useful, another ACL entry must set the rate
712 for the same key somewhere (otherwise it will always be zero).
717 # Read the rate; if it doesn't exist or is below the maximum
719 deny ratelimit = 100 / 5m / strict / noupdate
720 log_message = RATE: $sender_rate / $sender_rate_period \
721 (max $sender_rate_limit)
723 [... some other logic and tests...]
725 warn ratelimit = 100 / 5m / strict / per_cmd
726 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
727 (max $sender_rate_limit)
728 condition = ${if le{$sender_rate}{$sender_rate_limit}}
732 6. The variable $max_received_linelength contains the number of bytes in the
733 longest line that was received as part of the message, not counting the
734 line termination character(s).
736 7. Host lists can now include +ignore_defer and +include_defer, analagous to
737 +ignore_unknown and +include_unknown. These options should be used with
738 care, probably only in non-critical host lists such as whitelists.
740 8. There's a new option called queue_only_load_latch, which defaults true.
741 If set false when queue_only_load is greater than zero, Exim re-evaluates
742 the load for each incoming message in an SMTP session. Otherwise, once one
743 message is queued, the remainder are also.
745 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
746 cases when an SMTP session ends without sending QUIT. However, when Exim
747 itself is is bad trouble, such as being unable to write to its log files,
748 this ACL is not run, because it might try to do things (such as write to
749 log files) that make the situation even worse.
751 Like the QUIT ACL, this new ACL is provided to make it possible to gather
752 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
753 modifier is forbidden in this ACL.
755 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
756 to a string that indicates the reason for the termination of the SMTP
757 connection. The possible values are:
759 acl-drop Another ACL issued a "drop" command
760 bad-commands Too many unknown or non-mail commands
761 command-timeout Timeout while reading SMTP commands
762 connection-lost The SMTP connection has been lost
763 data-timeout Timeout while reading message data
764 local-scan-error The local_scan() function crashed
765 local-scan-timeout The local_scan() function timed out
766 signal-exit SIGTERM or SIGINT
767 synchronization-error SMTP synchronization error
768 tls-failed TLS failed to start
770 In most cases when an SMTP connection is closed without having received
771 QUIT, Exim sends an SMTP response message before actually closing the
772 connection. With the exception of acl-drop, the default message can be
773 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
774 "drop" verb in another ACL, it is the message from the other ACL that is
777 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
778 servers with individual queries. This is done by starting the query with
779 "servers=x:y:z;", where each item in the list may take one of two forms:
781 (1) If it is just a host name, the appropriate global option (mysql_servers
782 or pgsql_servers) is searched for a host of the same name, and the
783 remaining parameters (database, user, password) are taken from there.
785 (2) If it contains any slashes, it is taken as a complete parameter set.
787 The list of servers is used in exactly the same was as the global list.
788 Once a connection to a server has happened and a query has been
789 successfully executed, processing of the lookup ceases.
791 This feature is intended for use in master/slave situations where updates
792 are occurring, and one wants to update a master rather than a slave. If the
793 masters are in the list for reading, you might have:
795 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
797 In an updating lookup, you could then write
799 ${lookup mysql{servers=master; UPDATE ...}
801 If, on the other hand, the master is not to be used for reading lookups:
803 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
805 you can still update the master by
807 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
809 11. The message_body_newlines option (default FALSE, for backwards
810 compatibility) can be used to control whether newlines are present in
811 $message_body and $message_body_end. If it is FALSE, they are replaced by
818 1. There is a new log selector called smtp_no_mail, which is not included in
819 the default setting. When it is set, a line is written to the main log
820 whenever an accepted SMTP connection terminates without having issued a
823 2. When an item in a dnslists list is followed by = and & and a list of IP
824 addresses, the behaviour was not clear when the lookup returned more than
825 one IP address. This has been solved by the addition of == and =& for "all"
826 rather than the default "any" matching.
828 3. Up till now, the only control over which cipher suites GnuTLS uses has been
829 for the cipher algorithms. New options have been added to allow some of the
830 other parameters to be varied.
832 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
833 set, Exim compiles a runtime option called disable_fsync.
835 5. There is a new variable called $smtp_count_at_connection_start.
837 6. There's a new control called no_pipelining.
839 7. There are two new variables called $sending_ip_address and $sending_port.
840 These are set whenever an SMTP connection to another host has been set up.
842 8. The expansion of the helo_data option in the smtp transport now happens
843 after the connection to the server has been made.
845 9. There is a new expansion operator ${rfc2047d: that decodes strings that
846 are encoded as per RFC 2047.
848 10. There is a new log selector called "pid", which causes the current process
849 id to be added to every log line, in square brackets, immediately after the
852 11. Exim has been modified so that it flushes SMTP output before implementing
853 a delay in an ACL. It also flushes the output before performing a callout,
854 as this can take a substantial time. These behaviours can be disabled by
855 obeying control = no_delay_flush or control = no_callout_flush,
856 respectively, at some earlier stage of the connection.
858 12. There are two new expansion conditions that iterate over a list. They are
859 called forany and forall.
861 13. There's a new global option called dsn_from that can be used to vary the
862 contents of From: lines in bounces and other automatically generated
863 messages ("delivery status notifications" - hence the name of the option).
865 14. The smtp transport has a new option called hosts_avoid_pipelining.
867 15. By default, exigrep does case-insensitive matches. There is now a -I option
868 that makes it case-sensitive.
870 16. A number of new features ("addresses", "map", "filter", and "reduce") have
871 been added to string expansions to make it easier to process lists of
872 items, typically addresses.
874 17. There's a new ACL modifier called "continue". It does nothing of itself,
875 and processing of the ACL always continues with the next condition or
876 modifier. It is provided so that the side effects of expanding its argument
879 18. It is now possible to use newline and other control characters (those with
880 values less than 32, plus DEL) as separators in lists.
882 19. The exigrep utility now has a -v option, which inverts the matching
885 20. The host_find_failed option in the manualroute router can now be set to
892 No new features were added to 4.66.
898 No new features were added to 4.65.
904 1. ACL variables can now be given arbitrary names, as long as they start with
905 "acl_c" or "acl_m" (for connection variables and message variables), are at
906 least six characters long, with the sixth character being either a digit or
909 2. There is a new ACL modifier called log_reject_target. It makes it possible
910 to specify which logs are used for messages about ACL rejections.
912 3. There is a new authenticator called "dovecot". This is an interface to the
913 authentication facility of the Dovecot POP/IMAP server, which can support a
914 number of authentication methods.
916 4. The variable $message_headers_raw provides a concatenation of all the
917 messages's headers without any decoding. This is in contrast to
918 $message_headers, which does RFC2047 decoding on the header contents.
920 5. In a DNS black list, if two domain names, comma-separated, are given, the
921 second is used first to do an initial check, making use of any IP value
922 restrictions that are set. If there is a match, the first domain is used,
923 without any IP value restrictions, to get the TXT record.
925 6. All authenticators now have a server_condition option.
927 7. There is a new command-line option called -Mset. It is useful only in
928 conjunction with -be (that is, when testing string expansions). It must be
929 followed by a message id; Exim loads the given message from its spool
930 before doing the expansions.
932 8. Another similar new command-line option is called -bem. It operates like
933 -be except that it must be followed by the name of a file that contains a
936 9. When an address is delayed because of a 4xx response to a RCPT command, it
937 is now the combination of sender and recipient that is delayed in
938 subsequent queue runs until its retry time is reached.
940 10. Unary negation and the bitwise logical operators and, or, xor, not, and
941 shift, have been added to the eval: and eval10: expansion items.
943 11. The variables $interface_address and $interface_port have been renamed
944 as $received_ip_address and $received_port, to make it clear that they
945 relate to message reception rather than delivery. (The old names remain
946 available for compatibility.)
948 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
949 to vary the message that is sent when an SMTP command is accepted.
955 1. There is a new Boolean option called filter_prepend_home for the redirect
958 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
959 start of receiving a non-SMTP message, before any of the message has been
962 3. When an SMTP error message is specified in a "message" modifier in an ACL,
963 or in a :fail: or :defer: message in a redirect router, Exim now checks the
964 start of the message for an SMTP error code.
966 4. There is a new parameter for LDAP lookups called "referrals", which takes
967 one of the settings "follow" (the default) or "nofollow".
969 5. Version 20070721.2 of exipick now included, offering these new options:
971 After all other sorting options have bee processed, reverse order
972 before displaying messages (-R is synonym).
974 Randomize order of matching messages before displaying.
976 Instead of displaying the matching messages, display the sum
978 --sort <variable>[,<variable>...]
979 Before displaying matching messages, sort the messages according to
980 each messages value for each variable.
982 Negate the value for every test (returns inverse output from the
983 same criteria without --not).
989 1. The ${readsocket expansion item now supports Internet domain sockets as well
990 as Unix domain sockets. If the first argument begins "inet:", it must be of
991 the form "inet:host:port". The port is mandatory; it may be a number or the
992 name of a TCP port in /etc/services. The host may be a name, or it may be an
993 IP address. An ip address may optionally be enclosed in square brackets.
994 This is best for IPv6 addresses. For example:
996 ${readsocket{inet:[::1]:1234}{<request data>}...
998 Only a single host name may be given, but if looking it up yield more than
999 one IP address, they are each tried in turn until a connection is made. Once
1000 a connection has been made, the behaviour is as for ${readsocket with a Unix
1003 2. If a redirect router sets up file or pipe deliveries for more than one
1004 incoming address, and the relevant transport has batch_max set greater than
1005 one, a batch delivery now occurs.
1007 3. The appendfile transport has a new option called maildirfolder_create_regex.
1008 Its value is a regular expression. For a maildir delivery, this is matched
1009 against the maildir directory; if it matches, Exim ensures that a
1010 maildirfolder file is created alongside the new, cur, and tmp directories.
1016 The documentation is up-to-date for the 4.61 release. Major new features since
1017 the 4.60 release are:
1019 . An option called disable_ipv6, to disable the use of IPv6 completely.
1021 . An increase in the number of ACL variables to 20 of each type.
1023 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
1024 $2, $3, (though those are still set) because the numeric variables get used
1025 for other things in complicated expansions.
1027 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1029 . It is possible to use setclassresources() on some BSD OS to control the
1030 resources used in pipe deliveries.
1032 . A new ACL modifier called add_header, which can be used with any verb.
1034 . More errors are detectable in retry rules.
1036 There are a number of other additions too.
1042 The documentation is up-to-date for the 4.60 release. Major new features since
1043 the 4.50 release are:
1045 . Support for SQLite.
1047 . Support for IGNOREQUOTA in LMTP.
1049 . Extensions to the "submission mode" features.
1051 . Support for Client SMTP Authorization (CSA).
1053 . Support for ratelimiting hosts and users.
1055 . New expansion items to help with the BATV "prvs" scheme.
1057 . A "match_ip" condition, that matches an IP address against a list.
1059 There are many more minor changes.
projects / exim.git / blob