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.
16 1. The ACL conditions regex and mime_regex now capture substrings
17 into numeric variables $regex1 to 9, like the "match" expansion condition.
19 2. New $callout_address variable records the address used for a spam=,
20 malware= or verify= callout.
22 3. Transports now take a "max_parallel" option, to limit concurrency.
24 4. Expansion operators ${ipv6norm:<string>} and ${ipv6denorm:<string>}.
25 The latter expands to a 8-element colon-sep set of hex digits including
26 leading zeroes. A trailing ipv4-style dotted-decimal set is converted
27 to hex. Pure ipv4 addresses are converted to IPv4-mapped IPv6.
28 The former operator strips leading zeroes and collapses the longest
29 set of 0-groups to a double-colon.
31 5. New "-bP config" support, to dump the effective configuration.
33 6. New $dkim_key_length variable.
35 7. New base64d and base64 expansion items (the existing str2b64 being a
36 synonym of the latter). Add support in base64 for certificates.
38 8. New main configuration option "bounce_return_linesize_limit" to
39 avoid oversize bodies in bounces. The dafault value matches RFC
42 9. New $initial_cwd expansion variable.
48 1. Support for using the system standard CA bundle.
50 2. New expansion items $config_file, $config_dir, containing the file
51 and directory name of the main configuration file. Also $exim_version.
53 3. New "malware=" support for Avast.
55 4. New "spam=" variant option for Rspamd.
57 5. Assorted options on malware= and spam= scanners.
59 6. A commandline option to write a comment into the logfile.
61 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
62 be configured to make connections via socks5 proxies.
64 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
65 the transmission of UTF-8 envelope addresses.
67 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
68 used encoding of Maildir folder names.
70 10. A logging option for slow DNS lookups.
72 11. New ${env {<variable>}} expansion.
74 12. A non-SMTP authenticator using information from TLS client certificates.
76 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
77 Patch originally by Wolfgang Breyha.
79 14. Main option "dns_trust_aa" for trusting your local nameserver at the
86 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
87 DANE smtp draft to assess a secure chain of trust of the certificate
88 used to establish the TLS connection based on a TLSA record in the
91 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
92 and several new events have been created. The reason is because it has
93 been expanded beyond just firing events during the transport phase. Any
94 existing TPDA transport options will have to be rewritten to use a new
95 $event_name expansion variable in a condition. Refer to the
96 experimental-spec.txt for details and examples.
98 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
99 server certs used for TLS match the result of the MX lookup. It does
100 not use the same mechanism as DANE.
110 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
111 configured to expect an initial header from a proxy that will make the
112 actual external source IP:host be used in exim instead of the IP of the
113 proxy that is connecting to it.
115 2. New verify option header_names_ascii, which will check to make sure
116 there are no non-ASCII characters in header names. Exim itself handles
117 those non-ASCII characters, but downstream apps may not, so Exim can
118 detect and reject if those characters are present.
120 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
121 codepoints with valid ones.
123 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
124 command line and matching a regex against the return data for trigger
125 and a second regex to extract malware_name. The mail spoolfile name can
126 be included in the command line.
128 5. The smtp transport now supports options "tls_verify_hosts" and
129 "tls_try_verify_hosts". If either is set the certificate verification
130 is split from the encryption operation. The default remains that a failed
131 verification cancels the encryption.
133 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
134 lookup can now set a list of servers to use that is different from the
137 7. New command-line option -C for exiqgrep to specify alternate exim.conf
138 file when searching the queue.
140 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
142 9. Support for DNSSEC on outbound connections.
144 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
145 "certextract" to extract fields from them. Hash operators md5 and sha1
146 work over them for generating fingerprints, and a new sha256 operator
149 11. PRDR is now supported dy default.
151 12. OCSP stapling is now supported by default.
153 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
154 Delivery Status Notification messages in MIME format, and negociate
155 DSN features per RFC 3461.
161 1. New command-line option -bI:sieve will list all supported sieve extensions
162 of this Exim build on standard output, one per line.
163 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
164 query this to establish the correct list to include in the protocol's
165 SIEVE capability line.
167 2. If the -n option is combined with the -bP option, then the name of an
168 emitted option is not output, only the value (if visible to you).
169 For instance, "exim -n -bP pid_file_path" should just emit a pathname
170 followed by a newline, and no other text.
172 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
173 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
174 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
175 acceptable for security. (Option accepted but ignored if using OpenSSL).
176 Defaults to 1024, the old value. May be lowered only to 512, or raised as
177 far as you like. Raising this may hinder TLS interoperability with other
178 sites and is not currently recommended. Lowering this will permit you to
179 establish a TLS session which is not as secure as you might like.
181 Unless you really know what you are doing, leave it alone.
183 4. If not built with DISABLE_DNSSEC, Exim now has the main option
184 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
185 to send the DO flag to your recursive resolver. If you have a recursive
186 resolver, which can set the Authenticated Data (AD) flag in results, Exim
187 can now detect this. Exim does not perform validation itself, instead
188 relying upon a trusted path to the resolver.
190 Current status: work-in-progress; $sender_host_dnssec variable added.
192 5. DSCP support for outbound connections: on a transport using the smtp driver,
193 set "dscp = ef", for instance, to cause the connections to have the relevant
194 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
196 Similarly for inbound connections, there is a new control modifier, dscp,
197 so "warn control = dscp/ef" in the connect ACL, or after authentication.
199 Supported values depend upon system libraries. "exim -bI:dscp" to list the
200 ones Exim knows of. You can also set a raw number 0..0x3F.
202 6. The -G command-line flag is no longer ignored; it is now equivalent to an
203 ACL setting "control = suppress_local_fixups". The -L command-line flag
204 is now accepted and forces use of syslog, with the provided tag as the
205 process name. A few other flags used by Sendmail are now accepted and
208 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
209 ACL modifier; works for single-recipient mails which are recieved on and
210 deliverable via SMTP. Using the connection made for a recipient verify,
211 if requested before the verify, or a new one made for the purpose while
212 the inbound connection is still active. The bulk of the mail item is copied
213 direct from the inbound socket to the outbound (as well as the spool file).
214 When the source notifies the end of data, the data acceptance by the destination
215 is negociated before the acceptance is sent to the source. If the destination
216 does not accept the mail item, for example due to content-scanning, the item
217 is not accepted from the source and therefore there is no need to generate
218 a bounce mail. This is of benefit when providing a secondary-MX service.
219 The downside is that delays are under the control of the ultimate destination
222 The Recieved-by: header on items delivered by cutthrough is generated
223 early in reception rather than at the end; this will affect any timestamp
224 included. The log line showing delivery is recorded before that showing
225 reception; it uses a new ">>" tag instead of "=>".
227 To support the feature, verify-callout connections can now use ESMTP and TLS.
228 The usual smtp transport options are honoured, plus a (new, default everything)
229 hosts_verify_avoid_tls.
231 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
232 for specific access to the information for each connection. The old names
233 are present for now but deprecated.
235 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
237 8. New expansion operators ${listnamed:name} to get the content of a named list
238 and ${listcount:string} to count the items in a list.
240 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
241 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
242 modules. For some situations this is desirable, but we expect admin in
243 those situations to know they want the feature. More commonly, it means
244 that GUI user modules get loaded and are broken by the setuid Exim being
245 unable to access files specified in environment variables and passed
246 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
247 unless this new option is set.
249 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
250 so have also added a build option which can be used to build Exim with GnuTLS
251 but without trying to use any kind of PKCS11 support. Uncomment this in the
254 AVOID_GNUTLS_PKCS11=yes
256 10. The "acl = name" condition on an ACL now supports optional arguments.
257 New expansion item "${acl {name}{arg}...}" and expansion condition
258 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
259 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
260 Variable $acl_narg contains the number of arguments. If the ACL sets
261 a "message =" value this becomes the result of the expansion item,
262 or the value of $value for the expansion condition. If the ACL returns
263 accept the expansion condition is true; if reject, false. A defer
264 return results in a forced fail.
266 11. Routers and transports can now have multiple headers_add and headers_remove
267 option lines. The concatenated list is used.
269 12. New ACL modifier "remove_header" can remove headers before message gets
270 handled by routers/transports.
272 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
273 "aaaa" and "a" lookups is done and the full set of results returned.
275 14. New expansion variable $headers_added with content from ACL add_header
276 modifier (but not yet added to message).
278 15. New 8bitmime status logging option for received messages. Log field "M8S".
280 16. New authenticated_sender logging option, adding to log field "A".
282 17. New expansion variables $router_name and $transport_name. Useful
283 particularly for debug_print as -bt commandline option does not
284 require privilege whereas -d does.
286 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
287 proposed extension to SMTP from Eric Hall.
289 19. The pipe transport has gained the force_command option, to allow
290 decorating commands from user .forward pipe aliases with prefix
291 wrappers, for instance.
293 20. Callout connections can now AUTH; the same controls as normal delivery
296 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
297 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
298 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
299 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
300 dmarc_status. It adds new control flags dmarc_disable_verify and
301 dmarc_enable_forensic.
303 22. Add expansion variable $authenticated_fail_id, which is the username
304 provided to the authentication method which failed. It is available
305 for use in subsequent ACL processing (typically quit or notquit ACLs).
307 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
310 24. New ${hexquote:..string..} expansion operator converts non-printable
311 characters in the string to \xNN form.
313 25. Experimental TPDA (Transport Post Delivery Action) function added.
314 Patch provided by Axel Rau.
316 26. Experimental Redis lookup added. Patch provided by Warren Baker.
322 1. New authenticator driver, "gsasl". Server-only (at present).
323 This is a SASL interface, licensed under GPL, which can be found at
324 http://www.gnu.org/software/gsasl/.
325 This system does not provide sources of data for authentication, so
326 careful use needs to be made of the conditions in Exim.
328 2. New authenticator driver, "heimdal_gssapi". Server-only.
329 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
330 is no longer honoured for setuid programs by Heimdal. Use the
331 "server_keytab" option to point to the keytab.
333 3. The "pkg-config" system can now be used when building Exim to reference
334 cflags and library information for lookups and authenticators, rather
335 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
336 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
337 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
339 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
340 find the headers and libraries for PCRE.
342 4. New expansion variable $tls_bits.
344 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
345 be joined together with ASCII NUL characters to construct the key to pass
346 into the DBM library. Can be used with gsasl to access sasldb2 files as
349 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
351 Avoid release 1.0.1a if you can. Note that the default value of
352 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
353 increased susceptibility to attack. This may still have interoperability
354 implications for very old clients (see version 4.31 change 37) but
355 administrators can choose to make the trade-off themselves and restore
356 compatibility at the cost of session security.
358 7. Use of the new expansion variable $tls_sni in the main configuration option
359 tls_certificate will cause Exim to re-expand the option, if the client
360 sends the TLS Server Name Indication extension, to permit choosing a
361 different certificate; tls_privatekey will also be re-expanded. You must
362 still set these options to expand to valid files when $tls_sni is not set.
364 The SMTP Transport has gained the option tls_sni, which will set a hostname
365 for outbound TLS sessions, and set $tls_sni too.
367 A new log_selector, +tls_sni, has been added, to log received SNI values
368 for Exim as a server.
370 8. The existing "accept_8bitmime" option now defaults to true. This means
371 that Exim is deliberately not strictly RFC compliant. We're following
372 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
373 Those who disagree, or know that they are talking to mail servers that,
374 even today, are not 8-bit clean, need to turn off this option.
376 9. Exim can now be started with -bw (with an optional timeout, given as
377 -bw<timespec>). With this, stdin at startup is a socket that is
378 already listening for connections. This has a more modern name of
379 "socket activation", but forcing the activated socket to fd 0. We're
380 interested in adding more support for modern variants.
382 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
383 for numbers indicates multiplication by 1024^3.
385 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
386 gnutls_require_mac & gnutls_require_protocols are no longer supported.
387 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
388 string, documentation for which is at:
389 http://www.gnutls.org/manual/html_node/Priority-Strings.html
391 SNI support has been added to Exim's GnuTLS integration too.
393 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
394 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
396 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
397 is now available. If the contents of the file are valid, then Exim will
398 send that back in response to a TLS status request; this is OCSP Stapling.
399 Exim will not maintain the contents of the file in any way: administrators
400 are responsible for ensuring that it is up-to-date.
402 See "experimental-spec.txt" for more details.
404 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
405 identically to TXT record lookups.
407 14. New expansion variable $tod_epoch_l for higher-precision time.
409 15. New global option tls_dh_max_bits, defaulting to current value of NSS
410 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
411 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
413 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
414 Option can now be a path or an identifier for a standard prime.
415 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
416 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
419 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
420 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
421 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
427 1. New options for the ratelimit ACL condition: /count= and /unique=.
428 The /noupdate option has been replaced by a /readonly option.
430 2. The SMTP transport's protocol option may now be set to "smtps", to
431 use SSL-on-connect outbound.
433 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
434 there is a problem talking to the AV scanner, or the AV scanner running.
436 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
437 and check if the search item is a member of the list. This does not
438 support named lists, but does subject the list part to string expansion.
440 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
441 built, Exim no longer performs string expansion on the second string of
442 the match_* expansion conditions: "match_address", "match_domain",
443 "match_ip" & "match_local_part". Named lists can still be used.
449 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
450 or off in the resolver library.
456 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
457 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
458 libraries. The following global options have been added in support of
459 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
460 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
462 2. The pipe transport now takes a boolean option, "freeze_signal", default
463 false. When true, if the external delivery command exits on a signal then
464 Exim will freeze the message in the queue, instead of generating a bounce.
466 3. Log filenames may now use %M as an escape, instead of %D (still available).
467 The %M pattern expands to yyyymm, providing month-level resolution.
469 4. The $message_linecount variable is now updated for the maildir_tag option,
470 in the same way as $message_size, to reflect the real number of lines,
471 including any header additions or removals from transport.
473 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
474 Exim now selects entries randomly, to better scale in a cluster setup.
480 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
481 the flaw permitted the Exim run-time user to cause root to append to
482 arbitrary files of the attacker's choosing, with the content based
483 on content supplied by the attacker.
485 2. Exim now supports loading some lookup types at run-time, using your
486 platform's dlopen() functionality. This has limited platform support
487 and the intention is not to support every variant, it's limited to
488 dlopen(). This permits the main Exim binary to not be linked against
489 all the libraries needed for all the lookup types.
495 NOTE: this version is not guaranteed backwards-compatible, please read the
496 items below carefully
498 1. A new main configuration option, "openssl_options", is available if Exim
499 is built with SSL support provided by OpenSSL. The option allows
500 administrators to specify OpenSSL options to be used on connections;
501 typically this is to set bug compatibility features which the OpenSSL
502 developers have not enabled by default. There may be security
503 consequences for certain options, so these should not be changed
506 2. A new pipe transport option, "permit_coredumps", may help with problem
507 diagnosis in some scenarios. Note that Exim is typically installed as
508 a setuid binary, which on most OSes will inhibit coredumps by default,
509 so that safety mechanism would have to be overridden for this option to
510 be able to take effect.
512 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
513 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
514 Note that this switches Exim to use a new API ("INSTREAM") and a future
515 release of ClamAV will remove support for the old API ("STREAM").
517 The av_scanner option, when set to "clamd", now takes an optional third
518 part, "local", which causes Exim to pass a filename to ClamAV instead of
519 the file content. This is the same behaviour as when clamd is pointed at
520 a Unix-domain socket. For example:
522 av_scanner = clamd:192.0.2.3 1234:local
524 ClamAV's ExtendedDetectionInfo response format is now handled.
526 4. There is now a -bmalware option, restricted to admin users. This option
527 takes one parameter, a filename, and scans that file with Exim's
528 malware-scanning framework. This is intended purely as a debugging aid
529 to ensure that Exim's scanning is working, not to replace other tools.
530 Note that the ACL framework is not invoked, so if av_scanner references
531 ACL variables without a fallback then this will fail.
533 5. There is a new expansion operator, "reverse_ip", which will reverse IP
534 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
536 ${reverse_ip:192.0.2.4}
538 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
539 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
541 6. There is a new ACL control called "debug", to enable debug logging.
542 This allows selective logging of certain incoming transactions within
543 production environments, with some care. It takes two options, "tag"
544 and "opts"; "tag" is included in the filename of the log and "opts"
545 is used as per the -d<options> command-line option. Examples, which
546 don't all make sense in all contexts:
549 control = debug/tag=.$sender_host_address
550 control = debug/opts=+expand+acl
551 control = debug/tag=.$message_exim_id/opts=+expand
553 7. It has always been implicit in the design and the documentation that
554 "the Exim user" is not root. src/EDITME said that using root was
555 "very strongly discouraged". This is not enough to keep people from
556 shooting themselves in the foot in days when many don't configure Exim
557 themselves but via package build managers. The security consequences of
558 running various bits of network code are severe if there should be bugs in
559 them. As such, the Exim user may no longer be root. If configured
560 statically, Exim will refuse to build. If configured as ref:user then Exim
561 will exit shortly after start-up. If you must shoot yourself in the foot,
562 then henceforth you will have to maintain your own local patches to strip
565 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
566 condition logic to determine truth/failure and will fail to expand many
567 strings, bool_lax{} uses the router condition logic, where most strings
569 Note: bool{00} is false, bool_lax{00} is true.
571 9. Routers now support multiple "condition" tests.
573 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
574 Setting this allows an admin to define which entry in the tcpwrappers
575 config file will be used to control access to the daemon. This option
576 is only available when Exim is built with USE_TCP_WRAPPERS. The
577 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
580 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
581 the Exim run-time user, instead of root.
583 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
584 is forced on. This is mitigated by the new build option
585 TRUSTED_CONFIG_LIST which defines a list of configuration files which
586 are trusted; one per line. If a config file is owned by root and matches
587 a pathname in the list, then it may be invoked by the Exim build-time
588 user without Exim relinquishing root privileges.
590 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
591 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
592 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
593 include the main config. As a transition mechanism, we are temporarily
594 providing a work-around: the new build option WHITELIST_D_MACROS provides
595 a colon-separated list of macro names which may be overridden by the Exim
596 run-time user. The values of these macros are constrained to the regex
597 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
603 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
604 writable, the other to locking of MBX folders (not mbox).
606 2. MySQL stored procedures are now supported.
608 3. The dkim_domain transport option is now a list, not a single string, and
609 messages will be signed for each element in the list (discarding
612 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
613 in the presence of multiple character strings within the RR. Prior to 4.70,
614 only the first string would be returned. The dnsdb lookup now, by default,
615 preserves the pre-4.70 semantics, but also now takes an extended output
616 separator specification. The separator can be followed by a semicolon, to
617 concatenate the individual text strings together with no join character,
618 or by a comma and a second separator character, in which case the text
619 strings within a TXT record are joined on that second character.
620 Administrators are reminded that DNS provides no ordering guarantees
621 between multiple records in an RRset. For example:
623 foo.example. IN TXT "a" "b" "c"
624 foo.example. IN TXT "d" "e" "f"
626 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
627 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
628 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
634 1. Native DKIM support without an external library.
635 (Note that if no action to prevent it is taken, a straight upgrade will
636 result in DKIM verification of all signed incoming emails. See spec
637 for details on conditionally disabling)
639 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
641 3. There is now a bool{} expansion condition which maps certain strings to
642 true/false condition values (most likely of use in conjunction with the
643 and{} expansion operator).
645 4. The $spam_score, $spam_bar and $spam_report variables are now available
648 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
649 options, provided that Exim is invoked by an admin_user.
651 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
652 which increases compatibility with older clients at the cost of decreased
653 security. Don't set this unless you need to support such clients.
655 7. There is a new expansion operator, ${randint:...} which will produce a
656 "random" number less than the supplied integer. This randomness is
657 not guaranteed to be cryptographically strong, but depending upon how
658 Exim was built may be better than the most naive schemes.
660 8. Exim now explicitly ensures that SHA256 is available when linked against
663 9. The transport_filter_timeout option now applies to SMTP transports too.
669 1. Preliminary DKIM support in Experimental.
675 1. The body_linecount and body_zerocount C variables are now exported in the
678 2. When a dnslists lookup succeeds, the key that was looked up is now placed
679 in $dnslist_matched. When the key is an IP address, it is not reversed in
680 this variable (though it is, of course, in the actual lookup). In simple
683 deny dnslists = spamhaus.example
685 the key is also available in another variable (in this case,
686 $sender_host_address). In more complicated cases, however, this is not
687 true. For example, using a data lookup might generate a dnslists lookup
690 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
692 If this condition succeeds, the value in $dnslist_matched might be
693 192.168.6.7 (for example).
695 3. Authenticators now have a client_condition option. When Exim is running as
696 a client, it skips an authenticator whose client_condition expansion yields
697 "0", "no", or "false". This can be used, for example, to skip plain text
698 authenticators when the connection is not encrypted by a setting such as:
700 client_condition = ${if !eq{$tls_cipher}{}}
702 Note that the 4.67 documentation states that $tls_cipher contains the
703 cipher used for incoming messages. In fact, during SMTP delivery, it
704 contains the cipher used for the delivery. The same is true for
707 4. There is now a -Mvc <message-id> option, which outputs a copy of the
708 message to the standard output, in RFC 2822 format. The option can be used
709 only by an admin user.
711 5. There is now a /noupdate option for the ratelimit ACL condition. It
712 computes the rate and checks the limit as normal, but it does not update
713 the saved data. This means that, in relevant ACLs, it is possible to lookup
714 the existence of a specified (or auto-generated) ratelimit key without
715 incrementing the ratelimit counter for that key.
717 In order for this to be useful, another ACL entry must set the rate
718 for the same key somewhere (otherwise it will always be zero).
723 # Read the rate; if it doesn't exist or is below the maximum
725 deny ratelimit = 100 / 5m / strict / noupdate
726 log_message = RATE: $sender_rate / $sender_rate_period \
727 (max $sender_rate_limit)
729 [... some other logic and tests...]
731 warn ratelimit = 100 / 5m / strict / per_cmd
732 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
733 (max $sender_rate_limit)
734 condition = ${if le{$sender_rate}{$sender_rate_limit}}
738 6. The variable $max_received_linelength contains the number of bytes in the
739 longest line that was received as part of the message, not counting the
740 line termination character(s).
742 7. Host lists can now include +ignore_defer and +include_defer, analagous to
743 +ignore_unknown and +include_unknown. These options should be used with
744 care, probably only in non-critical host lists such as whitelists.
746 8. There's a new option called queue_only_load_latch, which defaults true.
747 If set false when queue_only_load is greater than zero, Exim re-evaluates
748 the load for each incoming message in an SMTP session. Otherwise, once one
749 message is queued, the remainder are also.
751 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
752 cases when an SMTP session ends without sending QUIT. However, when Exim
753 itself is is bad trouble, such as being unable to write to its log files,
754 this ACL is not run, because it might try to do things (such as write to
755 log files) that make the situation even worse.
757 Like the QUIT ACL, this new ACL is provided to make it possible to gather
758 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
759 modifier is forbidden in this ACL.
761 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
762 to a string that indicates the reason for the termination of the SMTP
763 connection. The possible values are:
765 acl-drop Another ACL issued a "drop" command
766 bad-commands Too many unknown or non-mail commands
767 command-timeout Timeout while reading SMTP commands
768 connection-lost The SMTP connection has been lost
769 data-timeout Timeout while reading message data
770 local-scan-error The local_scan() function crashed
771 local-scan-timeout The local_scan() function timed out
772 signal-exit SIGTERM or SIGINT
773 synchronization-error SMTP synchronization error
774 tls-failed TLS failed to start
776 In most cases when an SMTP connection is closed without having received
777 QUIT, Exim sends an SMTP response message before actually closing the
778 connection. With the exception of acl-drop, the default message can be
779 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
780 "drop" verb in another ACL, it is the message from the other ACL that is
783 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
784 servers with individual queries. This is done by starting the query with
785 "servers=x:y:z;", where each item in the list may take one of two forms:
787 (1) If it is just a host name, the appropriate global option (mysql_servers
788 or pgsql_servers) is searched for a host of the same name, and the
789 remaining parameters (database, user, password) are taken from there.
791 (2) If it contains any slashes, it is taken as a complete parameter set.
793 The list of servers is used in exactly the same was as the global list.
794 Once a connection to a server has happened and a query has been
795 successfully executed, processing of the lookup ceases.
797 This feature is intended for use in master/slave situations where updates
798 are occurring, and one wants to update a master rather than a slave. If the
799 masters are in the list for reading, you might have:
801 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
803 In an updating lookup, you could then write
805 ${lookup mysql{servers=master; UPDATE ...}
807 If, on the other hand, the master is not to be used for reading lookups:
809 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
811 you can still update the master by
813 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
815 11. The message_body_newlines option (default FALSE, for backwards
816 compatibility) can be used to control whether newlines are present in
817 $message_body and $message_body_end. If it is FALSE, they are replaced by
824 1. There is a new log selector called smtp_no_mail, which is not included in
825 the default setting. When it is set, a line is written to the main log
826 whenever an accepted SMTP connection terminates without having issued a
829 2. When an item in a dnslists list is followed by = and & and a list of IP
830 addresses, the behaviour was not clear when the lookup returned more than
831 one IP address. This has been solved by the addition of == and =& for "all"
832 rather than the default "any" matching.
834 3. Up till now, the only control over which cipher suites GnuTLS uses has been
835 for the cipher algorithms. New options have been added to allow some of the
836 other parameters to be varied.
838 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
839 set, Exim compiles a runtime option called disable_fsync.
841 5. There is a new variable called $smtp_count_at_connection_start.
843 6. There's a new control called no_pipelining.
845 7. There are two new variables called $sending_ip_address and $sending_port.
846 These are set whenever an SMTP connection to another host has been set up.
848 8. The expansion of the helo_data option in the smtp transport now happens
849 after the connection to the server has been made.
851 9. There is a new expansion operator ${rfc2047d: that decodes strings that
852 are encoded as per RFC 2047.
854 10. There is a new log selector called "pid", which causes the current process
855 id to be added to every log line, in square brackets, immediately after the
858 11. Exim has been modified so that it flushes SMTP output before implementing
859 a delay in an ACL. It also flushes the output before performing a callout,
860 as this can take a substantial time. These behaviours can be disabled by
861 obeying control = no_delay_flush or control = no_callout_flush,
862 respectively, at some earlier stage of the connection.
864 12. There are two new expansion conditions that iterate over a list. They are
865 called forany and forall.
867 13. There's a new global option called dsn_from that can be used to vary the
868 contents of From: lines in bounces and other automatically generated
869 messages ("delivery status notifications" - hence the name of the option).
871 14. The smtp transport has a new option called hosts_avoid_pipelining.
873 15. By default, exigrep does case-insensitive matches. There is now a -I option
874 that makes it case-sensitive.
876 16. A number of new features ("addresses", "map", "filter", and "reduce") have
877 been added to string expansions to make it easier to process lists of
878 items, typically addresses.
880 17. There's a new ACL modifier called "continue". It does nothing of itself,
881 and processing of the ACL always continues with the next condition or
882 modifier. It is provided so that the side effects of expanding its argument
885 18. It is now possible to use newline and other control characters (those with
886 values less than 32, plus DEL) as separators in lists.
888 19. The exigrep utility now has a -v option, which inverts the matching
891 20. The host_find_failed option in the manualroute router can now be set to
898 No new features were added to 4.66.
904 No new features were added to 4.65.
910 1. ACL variables can now be given arbitrary names, as long as they start with
911 "acl_c" or "acl_m" (for connection variables and message variables), are at
912 least six characters long, with the sixth character being either a digit or
915 2. There is a new ACL modifier called log_reject_target. It makes it possible
916 to specify which logs are used for messages about ACL rejections.
918 3. There is a new authenticator called "dovecot". This is an interface to the
919 authentication facility of the Dovecot POP/IMAP server, which can support a
920 number of authentication methods.
922 4. The variable $message_headers_raw provides a concatenation of all the
923 messages's headers without any decoding. This is in contrast to
924 $message_headers, which does RFC2047 decoding on the header contents.
926 5. In a DNS black list, if two domain names, comma-separated, are given, the
927 second is used first to do an initial check, making use of any IP value
928 restrictions that are set. If there is a match, the first domain is used,
929 without any IP value restrictions, to get the TXT record.
931 6. All authenticators now have a server_condition option.
933 7. There is a new command-line option called -Mset. It is useful only in
934 conjunction with -be (that is, when testing string expansions). It must be
935 followed by a message id; Exim loads the given message from its spool
936 before doing the expansions.
938 8. Another similar new command-line option is called -bem. It operates like
939 -be except that it must be followed by the name of a file that contains a
942 9. When an address is delayed because of a 4xx response to a RCPT command, it
943 is now the combination of sender and recipient that is delayed in
944 subsequent queue runs until its retry time is reached.
946 10. Unary negation and the bitwise logical operators and, or, xor, not, and
947 shift, have been added to the eval: and eval10: expansion items.
949 11. The variables $interface_address and $interface_port have been renamed
950 as $received_ip_address and $received_port, to make it clear that they
951 relate to message reception rather than delivery. (The old names remain
952 available for compatibility.)
954 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
955 to vary the message that is sent when an SMTP command is accepted.
961 1. There is a new Boolean option called filter_prepend_home for the redirect
964 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
965 start of receiving a non-SMTP message, before any of the message has been
968 3. When an SMTP error message is specified in a "message" modifier in an ACL,
969 or in a :fail: or :defer: message in a redirect router, Exim now checks the
970 start of the message for an SMTP error code.
972 4. There is a new parameter for LDAP lookups called "referrals", which takes
973 one of the settings "follow" (the default) or "nofollow".
975 5. Version 20070721.2 of exipick now included, offering these new options:
977 After all other sorting options have bee processed, reverse order
978 before displaying messages (-R is synonym).
980 Randomize order of matching messages before displaying.
982 Instead of displaying the matching messages, display the sum
984 --sort <variable>[,<variable>...]
985 Before displaying matching messages, sort the messages according to
986 each messages value for each variable.
988 Negate the value for every test (returns inverse output from the
989 same criteria without --not).
995 1. The ${readsocket expansion item now supports Internet domain sockets as well
996 as Unix domain sockets. If the first argument begins "inet:", it must be of
997 the form "inet:host:port". The port is mandatory; it may be a number or the
998 name of a TCP port in /etc/services. The host may be a name, or it may be an
999 IP address. An ip address may optionally be enclosed in square brackets.
1000 This is best for IPv6 addresses. For example:
1002 ${readsocket{inet:[::1]:1234}{<request data>}...
1004 Only a single host name may be given, but if looking it up yield more than
1005 one IP address, they are each tried in turn until a connection is made. Once
1006 a connection has been made, the behaviour is as for ${readsocket with a Unix
1009 2. If a redirect router sets up file or pipe deliveries for more than one
1010 incoming address, and the relevant transport has batch_max set greater than
1011 one, a batch delivery now occurs.
1013 3. The appendfile transport has a new option called maildirfolder_create_regex.
1014 Its value is a regular expression. For a maildir delivery, this is matched
1015 against the maildir directory; if it matches, Exim ensures that a
1016 maildirfolder file is created alongside the new, cur, and tmp directories.
1022 The documentation is up-to-date for the 4.61 release. Major new features since
1023 the 4.60 release are:
1025 . An option called disable_ipv6, to disable the use of IPv6 completely.
1027 . An increase in the number of ACL variables to 20 of each type.
1029 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
1030 $2, $3, (though those are still set) because the numeric variables get used
1031 for other things in complicated expansions.
1033 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1035 . It is possible to use setclassresources() on some BSD OS to control the
1036 resources used in pipe deliveries.
1038 . A new ACL modifier called add_header, which can be used with any verb.
1040 . More errors are detectable in retry rules.
1042 There are a number of other additions too.
1048 The documentation is up-to-date for the 4.60 release. Major new features since
1049 the 4.50 release are:
1051 . Support for SQLite.
1053 . Support for IGNOREQUOTA in LMTP.
1055 . Extensions to the "submission mode" features.
1057 . Support for Client SMTP Authorization (CSA).
1059 . Support for ratelimiting hosts and users.
1061 . New expansion items to help with the BATV "prvs" scheme.
1063 . A "match_ip" condition, that matches an IP address against a list.
1065 There are many more minor changes.
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