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.
22 1. Support for using the system standard CA bundle.
24 2. New expansion items $config_file, $config_dir, containing the file
25 and directory name of the main configuration file. Also $exim_version.
27 3. New "malware=" support for Avast.
29 4. New "spam=" variant option for Rspamd.
31 5. Assorted options on malware= and spam= scanners.
33 6. A commandline option to write a comment into the logfile.
35 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
36 be configured to make connections via socks5 proxies.
38 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
39 the transmission of UTF-8 envelope addresses.
41 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
42 used encoding of Maildir folder names.
44 10. A logging option for slow DNS lookups.
46 11. New ${env {<variable>}} expansion.
48 12. A non-SMTP authenticator using information from TLS client certificates.
50 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
51 Patch originally by Wolfgang Breyha.
53 14. Main option "dns_trust_aa" for trusting your local nameserver at the
60 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
61 DANE smtp draft to assess a secure chain of trust of the certificate
62 used to establish the TLS connection based on a TLSA record in the
65 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
66 and several new events have been created. The reason is because it has
67 been expanded beyond just firing events during the transport phase. Any
68 existing TPDA transport options will have to be rewritten to use a new
69 $event_name expansion variable in a condition. Refer to the
70 experimental-spec.txt for details and examples.
72 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
73 server certs used for TLS match the result of the MX lookup. It does
74 not use the same mechanism as DANE.
84 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
85 configured to expect an initial header from a proxy that will make the
86 actual external source IP:host be used in exim instead of the IP of the
87 proxy that is connecting to it.
89 2. New verify option header_names_ascii, which will check to make sure
90 there are no non-ASCII characters in header names. Exim itself handles
91 those non-ASCII characters, but downstream apps may not, so Exim can
92 detect and reject if those characters are present.
94 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
95 codepoints with valid ones.
97 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
98 command line and matching a regex against the return data for trigger
99 and a second regex to extract malware_name. The mail spoolfile name can
100 be included in the command line.
102 5. The smtp transport now supports options "tls_verify_hosts" and
103 "tls_try_verify_hosts". If either is set the certificate verification
104 is split from the encryption operation. The default remains that a failed
105 verification cancels the encryption.
107 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
108 lookup can now set a list of servers to use that is different from the
111 7. New command-line option -C for exiqgrep to specify alternate exim.conf
112 file when searching the queue.
114 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
116 9. Support for DNSSEC on outbound connections.
118 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
119 "certextract" to extract fields from them. Hash operators md5 and sha1
120 work over them for generating fingerprints, and a new sha256 operator
123 11. PRDR is now supported dy default.
125 12. OCSP stapling is now supported by default.
127 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
128 Delivery Status Notification messages in MIME format, and negociate
129 DSN features per RFC 3461.
135 1. New command-line option -bI:sieve will list all supported sieve extensions
136 of this Exim build on standard output, one per line.
137 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
138 query this to establish the correct list to include in the protocol's
139 SIEVE capability line.
141 2. If the -n option is combined with the -bP option, then the name of an
142 emitted option is not output, only the value (if visible to you).
143 For instance, "exim -n -bP pid_file_path" should just emit a pathname
144 followed by a newline, and no other text.
146 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
147 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
148 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
149 acceptable for security. (Option accepted but ignored if using OpenSSL).
150 Defaults to 1024, the old value. May be lowered only to 512, or raised as
151 far as you like. Raising this may hinder TLS interoperability with other
152 sites and is not currently recommended. Lowering this will permit you to
153 establish a TLS session which is not as secure as you might like.
155 Unless you really know what you are doing, leave it alone.
157 4. If not built with DISABLE_DNSSEC, Exim now has the main option
158 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
159 to send the DO flag to your recursive resolver. If you have a recursive
160 resolver, which can set the Authenticated Data (AD) flag in results, Exim
161 can now detect this. Exim does not perform validation itself, instead
162 relying upon a trusted path to the resolver.
164 Current status: work-in-progress; $sender_host_dnssec variable added.
166 5. DSCP support for outbound connections: on a transport using the smtp driver,
167 set "dscp = ef", for instance, to cause the connections to have the relevant
168 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
170 Similarly for inbound connections, there is a new control modifier, dscp,
171 so "warn control = dscp/ef" in the connect ACL, or after authentication.
173 Supported values depend upon system libraries. "exim -bI:dscp" to list the
174 ones Exim knows of. You can also set a raw number 0..0x3F.
176 6. The -G command-line flag is no longer ignored; it is now equivalent to an
177 ACL setting "control = suppress_local_fixups". The -L command-line flag
178 is now accepted and forces use of syslog, with the provided tag as the
179 process name. A few other flags used by Sendmail are now accepted and
182 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
183 ACL modifier; works for single-recipient mails which are recieved on and
184 deliverable via SMTP. Using the connection made for a recipient verify,
185 if requested before the verify, or a new one made for the purpose while
186 the inbound connection is still active. The bulk of the mail item is copied
187 direct from the inbound socket to the outbound (as well as the spool file).
188 When the source notifies the end of data, the data acceptance by the destination
189 is negociated before the acceptance is sent to the source. If the destination
190 does not accept the mail item, for example due to content-scanning, the item
191 is not accepted from the source and therefore there is no need to generate
192 a bounce mail. This is of benefit when providing a secondary-MX service.
193 The downside is that delays are under the control of the ultimate destination
196 The Recieved-by: header on items delivered by cutthrough is generated
197 early in reception rather than at the end; this will affect any timestamp
198 included. The log line showing delivery is recorded before that showing
199 reception; it uses a new ">>" tag instead of "=>".
201 To support the feature, verify-callout connections can now use ESMTP and TLS.
202 The usual smtp transport options are honoured, plus a (new, default everything)
203 hosts_verify_avoid_tls.
205 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
206 for specific access to the information for each connection. The old names
207 are present for now but deprecated.
209 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
211 8. New expansion operators ${listnamed:name} to get the content of a named list
212 and ${listcount:string} to count the items in a list.
214 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
215 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
216 modules. For some situations this is desirable, but we expect admin in
217 those situations to know they want the feature. More commonly, it means
218 that GUI user modules get loaded and are broken by the setuid Exim being
219 unable to access files specified in environment variables and passed
220 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
221 unless this new option is set.
223 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
224 so have also added a build option which can be used to build Exim with GnuTLS
225 but without trying to use any kind of PKCS11 support. Uncomment this in the
228 AVOID_GNUTLS_PKCS11=yes
230 10. The "acl = name" condition on an ACL now supports optional arguments.
231 New expansion item "${acl {name}{arg}...}" and expansion condition
232 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
233 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
234 Variable $acl_narg contains the number of arguments. If the ACL sets
235 a "message =" value this becomes the result of the expansion item,
236 or the value of $value for the expansion condition. If the ACL returns
237 accept the expansion condition is true; if reject, false. A defer
238 return results in a forced fail.
240 11. Routers and transports can now have multiple headers_add and headers_remove
241 option lines. The concatenated list is used.
243 12. New ACL modifier "remove_header" can remove headers before message gets
244 handled by routers/transports.
246 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
247 "aaaa" and "a" lookups is done and the full set of results returned.
249 14. New expansion variable $headers_added with content from ACL add_header
250 modifier (but not yet added to messsage).
252 15. New 8bitmime status logging option for received messages. Log field "M8S".
254 16. New authenticated_sender logging option, adding to log field "A".
256 17. New expansion variables $router_name and $transport_name. Useful
257 particularly for debug_print as -bt commandline option does not
258 require privilege whereas -d does.
260 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
261 proposed extension to SMTP from Eric Hall.
263 19. The pipe transport has gained the force_command option, to allow
264 decorating commands from user .forward pipe aliases with prefix
265 wrappers, for instance.
267 20. Callout connections can now AUTH; the same controls as normal delivery
270 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
271 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
272 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
273 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
274 dmarc_status. It adds new control flags dmarc_disable_verify and
275 dmarc_enable_forensic.
277 22. Add expansion variable $authenticated_fail_id, which is the username
278 provided to the authentication method which failed. It is available
279 for use in subsequent ACL processing (typically quit or notquit ACLs).
281 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
284 24. New ${hexquote:..string..} expansion operator converts non-printable
285 characters in the string to \xNN form.
287 25. Experimental TPDA (Transport Post Delivery Action) function added.
288 Patch provided by Axel Rau.
290 26. Experimental Redis lookup added. Patch provided by Warren Baker.
296 1. New authenticator driver, "gsasl". Server-only (at present).
297 This is a SASL interface, licensed under GPL, which can be found at
298 http://www.gnu.org/software/gsasl/.
299 This system does not provide sources of data for authentication, so
300 careful use needs to be made of the conditions in Exim.
302 2. New authenticator driver, "heimdal_gssapi". Server-only.
303 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
304 is no longer honoured for setuid programs by Heimdal. Use the
305 "server_keytab" option to point to the keytab.
307 3. The "pkg-config" system can now be used when building Exim to reference
308 cflags and library information for lookups and authenticators, rather
309 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
310 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
311 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
313 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
314 find the headers and libraries for PCRE.
316 4. New expansion variable $tls_bits.
318 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
319 be joined together with ASCII NUL characters to construct the key to pass
320 into the DBM library. Can be used with gsasl to access sasldb2 files as
323 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
325 Avoid release 1.0.1a if you can. Note that the default value of
326 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
327 increased susceptibility to attack. This may still have interoperability
328 implications for very old clients (see version 4.31 change 37) but
329 administrators can choose to make the trade-off themselves and restore
330 compatibility at the cost of session security.
332 7. Use of the new expansion variable $tls_sni in the main configuration option
333 tls_certificate will cause Exim to re-expand the option, if the client
334 sends the TLS Server Name Indication extension, to permit choosing a
335 different certificate; tls_privatekey will also be re-expanded. You must
336 still set these options to expand to valid files when $tls_sni is not set.
338 The SMTP Transport has gained the option tls_sni, which will set a hostname
339 for outbound TLS sessions, and set $tls_sni too.
341 A new log_selector, +tls_sni, has been added, to log received SNI values
342 for Exim as a server.
344 8. The existing "accept_8bitmime" option now defaults to true. This means
345 that Exim is deliberately not strictly RFC compliant. We're following
346 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
347 Those who disagree, or know that they are talking to mail servers that,
348 even today, are not 8-bit clean, need to turn off this option.
350 9. Exim can now be started with -bw (with an optional timeout, given as
351 -bw<timespec>). With this, stdin at startup is a socket that is
352 already listening for connections. This has a more modern name of
353 "socket activation", but forcing the activated socket to fd 0. We're
354 interested in adding more support for modern variants.
356 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
357 for numbers indicates multiplication by 1024^3.
359 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
360 gnutls_require_mac & gnutls_require_protocols are no longer supported.
361 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
362 string, documentation for which is at:
363 http://www.gnutls.org/manual/html_node/Priority-Strings.html
365 SNI support has been added to Exim's GnuTLS integration too.
367 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
368 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
370 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
371 is now available. If the contents of the file are valid, then Exim will
372 send that back in response to a TLS status request; this is OCSP Stapling.
373 Exim will not maintain the contents of the file in any way: administrators
374 are responsible for ensuring that it is up-to-date.
376 See "experimental-spec.txt" for more details.
378 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
379 identically to TXT record lookups.
381 14. New expansion variable $tod_epoch_l for higher-precision time.
383 15. New global option tls_dh_max_bits, defaulting to current value of NSS
384 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
385 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
387 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
388 Option can now be a path or an identifier for a standard prime.
389 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
390 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
393 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
394 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
395 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
401 1. New options for the ratelimit ACL condition: /count= and /unique=.
402 The /noupdate option has been replaced by a /readonly option.
404 2. The SMTP transport's protocol option may now be set to "smtps", to
405 use SSL-on-connect outbound.
407 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
408 there is a problem talking to the AV scanner, or the AV scanner running.
410 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
411 and check if the search item is a member of the list. This does not
412 support named lists, but does subject the list part to string expansion.
414 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
415 built, Exim no longer performs string expansion on the second string of
416 the match_* expansion conditions: "match_address", "match_domain",
417 "match_ip" & "match_local_part". Named lists can still be used.
423 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
424 or off in the resolver library.
430 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
431 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
432 libraries. The following global options have been added in support of
433 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
434 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
436 2. The pipe transport now takes a boolean option, "freeze_signal", default
437 false. When true, if the external delivery command exits on a signal then
438 Exim will freeze the message in the queue, instead of generating a bounce.
440 3. Log filenames may now use %M as an escape, instead of %D (still available).
441 The %M pattern expands to yyyymm, providing month-level resolution.
443 4. The $message_linecount variable is now updated for the maildir_tag option,
444 in the same way as $message_size, to reflect the real number of lines,
445 including any header additions or removals from transport.
447 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
448 Exim now selects entries randomly, to better scale in a cluster setup.
454 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
455 the flaw permitted the Exim run-time user to cause root to append to
456 arbitrary files of the attacker's choosing, with the content based
457 on content supplied by the attacker.
459 2. Exim now supports loading some lookup types at run-time, using your
460 platform's dlopen() functionality. This has limited platform support
461 and the intention is not to support every variant, it's limited to
462 dlopen(). This permits the main Exim binary to not be linked against
463 all the libraries needed for all the lookup types.
469 NOTE: this version is not guaranteed backwards-compatible, please read the
470 items below carefully
472 1. A new main configuration option, "openssl_options", is available if Exim
473 is built with SSL support provided by OpenSSL. The option allows
474 administrators to specify OpenSSL options to be used on connections;
475 typically this is to set bug compatibility features which the OpenSSL
476 developers have not enabled by default. There may be security
477 consequences for certain options, so these should not be changed
480 2. A new pipe transport option, "permit_coredumps", may help with problem
481 diagnosis in some scenarios. Note that Exim is typically installed as
482 a setuid binary, which on most OSes will inhibit coredumps by default,
483 so that safety mechanism would have to be overridden for this option to
484 be able to take effect.
486 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
487 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
488 Note that this switches Exim to use a new API ("INSTREAM") and a future
489 release of ClamAV will remove support for the old API ("STREAM").
491 The av_scanner option, when set to "clamd", now takes an optional third
492 part, "local", which causes Exim to pass a filename to ClamAV instead of
493 the file content. This is the same behaviour as when clamd is pointed at
494 a Unix-domain socket. For example:
496 av_scanner = clamd:192.0.2.3 1234:local
498 ClamAV's ExtendedDetectionInfo response format is now handled.
500 4. There is now a -bmalware option, restricted to admin users. This option
501 takes one parameter, a filename, and scans that file with Exim's
502 malware-scanning framework. This is intended purely as a debugging aid
503 to ensure that Exim's scanning is working, not to replace other tools.
504 Note that the ACL framework is not invoked, so if av_scanner references
505 ACL variables without a fallback then this will fail.
507 5. There is a new expansion operator, "reverse_ip", which will reverse IP
508 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
510 ${reverse_ip:192.0.2.4}
512 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
513 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
515 6. There is a new ACL control called "debug", to enable debug logging.
516 This allows selective logging of certain incoming transactions within
517 production environments, with some care. It takes two options, "tag"
518 and "opts"; "tag" is included in the filename of the log and "opts"
519 is used as per the -d<options> command-line option. Examples, which
520 don't all make sense in all contexts:
523 control = debug/tag=.$sender_host_address
524 control = debug/opts=+expand+acl
525 control = debug/tag=.$message_exim_id/opts=+expand
527 7. It has always been implicit in the design and the documentation that
528 "the Exim user" is not root. src/EDITME said that using root was
529 "very strongly discouraged". This is not enough to keep people from
530 shooting themselves in the foot in days when many don't configure Exim
531 themselves but via package build managers. The security consequences of
532 running various bits of network code are severe if there should be bugs in
533 them. As such, the Exim user may no longer be root. If configured
534 statically, Exim will refuse to build. If configured as ref:user then Exim
535 will exit shortly after start-up. If you must shoot yourself in the foot,
536 then henceforth you will have to maintain your own local patches to strip
539 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
540 condition logic to determine truth/failure and will fail to expand many
541 strings, bool_lax{} uses the router condition logic, where most strings
543 Note: bool{00} is false, bool_lax{00} is true.
545 9. Routers now support multiple "condition" tests.
547 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
548 Setting this allows an admin to define which entry in the tcpwrappers
549 config file will be used to control access to the daemon. This option
550 is only available when Exim is built with USE_TCP_WRAPPERS. The
551 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
554 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
555 the Exim run-time user, instead of root.
557 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
558 is forced on. This is mitigated by the new build option
559 TRUSTED_CONFIG_LIST which defines a list of configuration files which
560 are trusted; one per line. If a config file is owned by root and matches
561 a pathname in the list, then it may be invoked by the Exim build-time
562 user without Exim relinquishing root privileges.
564 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
565 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
566 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
567 include the main config. As a transition mechanism, we are temporarily
568 providing a work-around: the new build option WHITELIST_D_MACROS provides
569 a colon-separated list of macro names which may be overridden by the Exim
570 run-time user. The values of these macros are constrained to the regex
571 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
577 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
578 writable, the other to locking of MBX folders (not mbox).
580 2. MySQL stored procedures are now supported.
582 3. The dkim_domain transport option is now a list, not a single string, and
583 messages will be signed for each element in the list (discarding
586 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
587 in the presence of multiple character strings within the RR. Prior to 4.70,
588 only the first string would be returned. The dnsdb lookup now, by default,
589 preserves the pre-4.70 semantics, but also now takes an extended output
590 separator specification. The separator can be followed by a semicolon, to
591 concatenate the individual text strings together with no join character,
592 or by a comma and a second separator character, in which case the text
593 strings within a TXT record are joined on that second character.
594 Administrators are reminded that DNS provides no ordering guarantees
595 between multiple records in an RRset. For example:
597 foo.example. IN TXT "a" "b" "c"
598 foo.example. IN TXT "d" "e" "f"
600 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
601 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
602 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
608 1. Native DKIM support without an external library.
609 (Note that if no action to prevent it is taken, a straight upgrade will
610 result in DKIM verification of all signed incoming emails. See spec
611 for details on conditionally disabling)
613 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
615 3. There is now a bool{} expansion condition which maps certain strings to
616 true/false condition values (most likely of use in conjunction with the
617 and{} expansion operator).
619 4. The $spam_score, $spam_bar and $spam_report variables are now available
622 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
623 options, provided that Exim is invoked by an admin_user.
625 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
626 which increases compatibility with older clients at the cost of decreased
627 security. Don't set this unless you need to support such clients.
629 7. There is a new expansion operator, ${randint:...} which will produce a
630 "random" number less than the supplied integer. This randomness is
631 not guaranteed to be cryptographically strong, but depending upon how
632 Exim was built may be better than the most naive schemes.
634 8. Exim now explicitly ensures that SHA256 is available when linked against
637 9. The transport_filter_timeout option now applies to SMTP transports too.
643 1. Preliminary DKIM support in Experimental.
649 1. The body_linecount and body_zerocount C variables are now exported in the
652 2. When a dnslists lookup succeeds, the key that was looked up is now placed
653 in $dnslist_matched. When the key is an IP address, it is not reversed in
654 this variable (though it is, of course, in the actual lookup). In simple
657 deny dnslists = spamhaus.example
659 the key is also available in another variable (in this case,
660 $sender_host_address). In more complicated cases, however, this is not
661 true. For example, using a data lookup might generate a dnslists lookup
664 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
666 If this condition succeeds, the value in $dnslist_matched might be
667 192.168.6.7 (for example).
669 3. Authenticators now have a client_condition option. When Exim is running as
670 a client, it skips an authenticator whose client_condition expansion yields
671 "0", "no", or "false". This can be used, for example, to skip plain text
672 authenticators when the connection is not encrypted by a setting such as:
674 client_condition = ${if !eq{$tls_cipher}{}}
676 Note that the 4.67 documentation states that $tls_cipher contains the
677 cipher used for incoming messages. In fact, during SMTP delivery, it
678 contains the cipher used for the delivery. The same is true for
681 4. There is now a -Mvc <message-id> option, which outputs a copy of the
682 message to the standard output, in RFC 2822 format. The option can be used
683 only by an admin user.
685 5. There is now a /noupdate option for the ratelimit ACL condition. It
686 computes the rate and checks the limit as normal, but it does not update
687 the saved data. This means that, in relevant ACLs, it is possible to lookup
688 the existence of a specified (or auto-generated) ratelimit key without
689 incrementing the ratelimit counter for that key.
691 In order for this to be useful, another ACL entry must set the rate
692 for the same key somewhere (otherwise it will always be zero).
697 # Read the rate; if it doesn't exist or is below the maximum
699 deny ratelimit = 100 / 5m / strict / noupdate
700 log_message = RATE: $sender_rate / $sender_rate_period \
701 (max $sender_rate_limit)
703 [... some other logic and tests...]
705 warn ratelimit = 100 / 5m / strict / per_cmd
706 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
707 (max $sender_rate_limit)
708 condition = ${if le{$sender_rate}{$sender_rate_limit}}
712 6. The variable $max_received_linelength contains the number of bytes in the
713 longest line that was received as part of the message, not counting the
714 line termination character(s).
716 7. Host lists can now include +ignore_defer and +include_defer, analagous to
717 +ignore_unknown and +include_unknown. These options should be used with
718 care, probably only in non-critical host lists such as whitelists.
720 8. There's a new option called queue_only_load_latch, which defaults true.
721 If set false when queue_only_load is greater than zero, Exim re-evaluates
722 the load for each incoming message in an SMTP session. Otherwise, once one
723 message is queued, the remainder are also.
725 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
726 cases when an SMTP session ends without sending QUIT. However, when Exim
727 itself is is bad trouble, such as being unable to write to its log files,
728 this ACL is not run, because it might try to do things (such as write to
729 log files) that make the situation even worse.
731 Like the QUIT ACL, this new ACL is provided to make it possible to gather
732 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
733 modifier is forbidden in this ACL.
735 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
736 to a string that indicates the reason for the termination of the SMTP
737 connection. The possible values are:
739 acl-drop Another ACL issued a "drop" command
740 bad-commands Too many unknown or non-mail commands
741 command-timeout Timeout while reading SMTP commands
742 connection-lost The SMTP connection has been lost
743 data-timeout Timeout while reading message data
744 local-scan-error The local_scan() function crashed
745 local-scan-timeout The local_scan() function timed out
746 signal-exit SIGTERM or SIGINT
747 synchronization-error SMTP synchronization error
748 tls-failed TLS failed to start
750 In most cases when an SMTP connection is closed without having received
751 QUIT, Exim sends an SMTP response message before actually closing the
752 connection. With the exception of acl-drop, the default message can be
753 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
754 "drop" verb in another ACL, it is the message from the other ACL that is
757 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
758 servers with individual queries. This is done by starting the query with
759 "servers=x:y:z;", where each item in the list may take one of two forms:
761 (1) If it is just a host name, the appropriate global option (mysql_servers
762 or pgsql_servers) is searched for a host of the same name, and the
763 remaining parameters (database, user, password) are taken from there.
765 (2) If it contains any slashes, it is taken as a complete parameter set.
767 The list of servers is used in exactly the same was as the global list.
768 Once a connection to a server has happened and a query has been
769 successfully executed, processing of the lookup ceases.
771 This feature is intended for use in master/slave situations where updates
772 are occurring, and one wants to update a master rather than a slave. If the
773 masters are in the list for reading, you might have:
775 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
777 In an updating lookup, you could then write
779 ${lookup mysql{servers=master; UPDATE ...}
781 If, on the other hand, the master is not to be used for reading lookups:
783 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
785 you can still update the master by
787 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
789 11. The message_body_newlines option (default FALSE, for backwards
790 compatibility) can be used to control whether newlines are present in
791 $message_body and $message_body_end. If it is FALSE, they are replaced by
798 1. There is a new log selector called smtp_no_mail, which is not included in
799 the default setting. When it is set, a line is written to the main log
800 whenever an accepted SMTP connection terminates without having issued a
803 2. When an item in a dnslists list is followed by = and & and a list of IP
804 addresses, the behaviour was not clear when the lookup returned more than
805 one IP address. This has been solved by the addition of == and =& for "all"
806 rather than the default "any" matching.
808 3. Up till now, the only control over which cipher suites GnuTLS uses has been
809 for the cipher algorithms. New options have been added to allow some of the
810 other parameters to be varied.
812 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
813 set, Exim compiles a runtime option called disable_fsync.
815 5. There is a new variable called $smtp_count_at_connection_start.
817 6. There's a new control called no_pipelining.
819 7. There are two new variables called $sending_ip_address and $sending_port.
820 These are set whenever an SMTP connection to another host has been set up.
822 8. The expansion of the helo_data option in the smtp transport now happens
823 after the connection to the server has been made.
825 9. There is a new expansion operator ${rfc2047d: that decodes strings that
826 are encoded as per RFC 2047.
828 10. There is a new log selector called "pid", which causes the current process
829 id to be added to every log line, in square brackets, immediately after the
832 11. Exim has been modified so that it flushes SMTP output before implementing
833 a delay in an ACL. It also flushes the output before performing a callout,
834 as this can take a substantial time. These behaviours can be disabled by
835 obeying control = no_delay_flush or control = no_callout_flush,
836 respectively, at some earlier stage of the connection.
838 12. There are two new expansion conditions that iterate over a list. They are
839 called forany and forall.
841 13. There's a new global option called dsn_from that can be used to vary the
842 contents of From: lines in bounces and other automatically generated
843 messages ("delivery status notifications" - hence the name of the option).
845 14. The smtp transport has a new option called hosts_avoid_pipelining.
847 15. By default, exigrep does case-insensitive matches. There is now a -I option
848 that makes it case-sensitive.
850 16. A number of new features ("addresses", "map", "filter", and "reduce") have
851 been added to string expansions to make it easier to process lists of
852 items, typically addresses.
854 17. There's a new ACL modifier called "continue". It does nothing of itself,
855 and processing of the ACL always continues with the next condition or
856 modifier. It is provided so that the side effects of expanding its argument
859 18. It is now possible to use newline and other control characters (those with
860 values less than 32, plus DEL) as separators in lists.
862 19. The exigrep utility now has a -v option, which inverts the matching
865 20. The host_find_failed option in the manualroute router can now be set to
872 No new features were added to 4.66.
878 No new features were added to 4.65.
884 1. ACL variables can now be given arbitrary names, as long as they start with
885 "acl_c" or "acl_m" (for connection variables and message variables), are at
886 least six characters long, with the sixth character being either a digit or
889 2. There is a new ACL modifier called log_reject_target. It makes it possible
890 to specify which logs are used for messages about ACL rejections.
892 3. There is a new authenticator called "dovecot". This is an interface to the
893 authentication facility of the Dovecot POP/IMAP server, which can support a
894 number of authentication methods.
896 4. The variable $message_headers_raw provides a concatenation of all the
897 messages's headers without any decoding. This is in contrast to
898 $message_headers, which does RFC2047 decoding on the header contents.
900 5. In a DNS black list, if two domain names, comma-separated, are given, the
901 second is used first to do an initial check, making use of any IP value
902 restrictions that are set. If there is a match, the first domain is used,
903 without any IP value restrictions, to get the TXT record.
905 6. All authenticators now have a server_condition option.
907 7. There is a new command-line option called -Mset. It is useful only in
908 conjunction with -be (that is, when testing string expansions). It must be
909 followed by a message id; Exim loads the given message from its spool
910 before doing the expansions.
912 8. Another similar new command-line option is called -bem. It operates like
913 -be except that it must be followed by the name of a file that contains a
916 9. When an address is delayed because of a 4xx response to a RCPT command, it
917 is now the combination of sender and recipient that is delayed in
918 subsequent queue runs until its retry time is reached.
920 10. Unary negation and the bitwise logical operators and, or, xor, not, and
921 shift, have been added to the eval: and eval10: expansion items.
923 11. The variables $interface_address and $interface_port have been renamed
924 as $received_ip_address and $received_port, to make it clear that they
925 relate to message reception rather than delivery. (The old names remain
926 available for compatibility.)
928 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
929 to vary the message that is sent when an SMTP command is accepted.
935 1. There is a new Boolean option called filter_prepend_home for the redirect
938 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
939 start of receiving a non-SMTP message, before any of the message has been
942 3. When an SMTP error message is specified in a "message" modifier in an ACL,
943 or in a :fail: or :defer: message in a redirect router, Exim now checks the
944 start of the message for an SMTP error code.
946 4. There is a new parameter for LDAP lookups called "referrals", which takes
947 one of the settings "follow" (the default) or "nofollow".
949 5. Version 20070721.2 of exipick now included, offering these new options:
951 After all other sorting options have bee processed, reverse order
952 before displaying messages (-R is synonym).
954 Randomize order of matching messages before displaying.
956 Instead of displaying the matching messages, display the sum
958 --sort <variable>[,<variable>...]
959 Before displaying matching messages, sort the messages according to
960 each messages value for each variable.
962 Negate the value for every test (returns inverse output from the
963 same criteria without --not).
969 1. The ${readsocket expansion item now supports Internet domain sockets as well
970 as Unix domain sockets. If the first argument begins "inet:", it must be of
971 the form "inet:host:port". The port is mandatory; it may be a number or the
972 name of a TCP port in /etc/services. The host may be a name, or it may be an
973 IP address. An ip address may optionally be enclosed in square brackets.
974 This is best for IPv6 addresses. For example:
976 ${readsocket{inet:[::1]:1234}{<request data>}...
978 Only a single host name may be given, but if looking it up yield more than
979 one IP address, they are each tried in turn until a connection is made. Once
980 a connection has been made, the behaviour is as for ${readsocket with a Unix
983 2. If a redirect router sets up file or pipe deliveries for more than one
984 incoming address, and the relevant transport has batch_max set greater than
985 one, a batch delivery now occurs.
987 3. The appendfile transport has a new option called maildirfolder_create_regex.
988 Its value is a regular expression. For a maildir delivery, this is matched
989 against the maildir directory; if it matches, Exim ensures that a
990 maildirfolder file is created alongside the new, cur, and tmp directories.
996 The documentation is up-to-date for the 4.61 release. Major new features since
997 the 4.60 release are:
999 . An option called disable_ipv6, to disable the use of IPv6 completely.
1001 . An increase in the number of ACL variables to 20 of each type.
1003 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
1004 $2, $3, (though those are still set) because the numeric variables get used
1005 for other things in complicated expansions.
1007 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1009 . It is possible to use setclassresources() on some BSD OS to control the
1010 resources used in pipe deliveries.
1012 . A new ACL modifier called add_header, which can be used with any verb.
1014 . More errors are detectable in retry rules.
1016 There are a number of other additions too.
1022 The documentation is up-to-date for the 4.60 release. Major new features since
1023 the 4.50 release are:
1025 . Support for SQLite.
1027 . Support for IGNOREQUOTA in LMTP.
1029 . Extensions to the "submission mode" features.
1031 . Support for Client SMTP Authorization (CSA).
1033 . Support for ratelimiting hosts and users.
1035 . New expansion items to help with the BATV "prvs" scheme.
1037 . A "match_ip" condition, that matches an IP address against a list.
1039 There are many more minor changes.
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