4 This file contains descriptions of new features that have been added to Exim.
5 Before a formal release, there may be quite a lot of detail so that people can
6 test from the snapshots or the CVS before the documentation is updated. Once
7 the documentation is updated, this file is reduced to a short list.
12 1. The new perl_taintmode option allows to run the embedded perl
13 interpreter in taint mode.
15 2. New log_selector: dnssec, adds a "DS" tag to acceptance and delivery lines.
17 3. Speculative debugging, via a "kill" option to the "control=debug" ACL
20 4. New expansion item ${sha3:<string>} / ${sha3_<N>:<string>}.
21 N can be 224, 256 (default), 384, 512.
22 With GnuTLS 3.5.0 or later, only.
24 5. Facility for named queues: A commandline argument can specify
25 the queue name for a queue operation, and an ACL modifier can set
26 the queue to be used for a message. A $queue_name variable gives
29 6. New expansion operators base32/base32d.
31 7. The CHUNKING ESMTP extension from RFC 3030. May give some slight
32 performance increase and network load decrease. Main config option
33 chunking_advertise_hosts, and smtp transport option hosts_try_chunking
36 8. LMDB lookup support, as Experimental. Patch supplied by Andrew Colin Kissa.
38 9. Expansion operator escape8bit, like escape but not touching newline etc..
40 10. Feature macros, generated from compile options. All start with "_HAVE_"
41 and go on with some roughly recognisable name. Driver macros, for
42 router, transport and authentication drivers; names starting with "_DRVR_".
43 Option macros, for each configuration-file option; all start with "_OPT_".
44 Use the "-bP macros" command-line option to see what is present.
46 11. Integer values for options can take a "G" multiplier.
48 12. defer=pass option for the ACL control cutthrough_delivery, to reflect 4xx
49 returns from the target back to the initiator, rather than spooling the
52 13. New built-in constants available for tls_dhparam and default changed.
58 1. The ACL conditions regex and mime_regex now capture substrings
59 into numeric variables $regex1 to 9, like the "match" expansion condition.
61 2. New $callout_address variable records the address used for a spam=,
62 malware= or verify= callout.
64 3. Transports now take a "max_parallel" option, to limit concurrency.
66 4. Expansion operators ${ipv6norm:<string>} and ${ipv6denorm:<string>}.
67 The latter expands to a 8-element colon-sep set of hex digits including
68 leading zeroes. A trailing ipv4-style dotted-decimal set is converted
69 to hex. Pure ipv4 addresses are converted to IPv4-mapped IPv6.
70 The former operator strips leading zeroes and collapses the longest
71 set of 0-groups to a double-colon.
73 5. New "-bP config" support, to dump the effective configuration.
75 6. New $dkim_key_length variable.
77 7. New base64d and base64 expansion items (the existing str2b64 being a
78 synonym of the latter). Add support in base64 for certificates.
80 8. New main configuration option "bounce_return_linesize_limit" to
81 avoid oversize bodies in bounces. The dafault value matches RFC
84 9. New $initial_cwd expansion variable.
90 1. Support for using the system standard CA bundle.
92 2. New expansion items $config_file, $config_dir, containing the file
93 and directory name of the main configuration file. Also $exim_version.
95 3. New "malware=" support for Avast.
97 4. New "spam=" variant option for Rspamd.
99 5. Assorted options on malware= and spam= scanners.
101 6. A commandline option to write a comment into the logfile.
103 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
104 be configured to make connections via socks5 proxies.
106 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
107 the transmission of UTF-8 envelope addresses.
109 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
110 used encoding of Maildir folder names.
112 10. A logging option for slow DNS lookups.
114 11. New ${env {<variable>}} expansion.
116 12. A non-SMTP authenticator using information from TLS client certificates.
118 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
119 Patch originally by Wolfgang Breyha.
121 14. Main option "dns_trust_aa" for trusting your local nameserver at the
122 same level as DNSSEC.
128 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
129 DANE smtp draft to assess a secure chain of trust of the certificate
130 used to establish the TLS connection based on a TLSA record in the
131 domain of the sender.
133 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
134 and several new events have been created. The reason is because it has
135 been expanded beyond just firing events during the transport phase. Any
136 existing TPDA transport options will have to be rewritten to use a new
137 $event_name expansion variable in a condition. Refer to the
138 experimental-spec.txt for details and examples.
140 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
141 server certs used for TLS match the result of the MX lookup. It does
142 not use the same mechanism as DANE.
152 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
153 configured to expect an initial header from a proxy that will make the
154 actual external source IP:host be used in exim instead of the IP of the
155 proxy that is connecting to it.
157 2. New verify option header_names_ascii, which will check to make sure
158 there are no non-ASCII characters in header names. Exim itself handles
159 those non-ASCII characters, but downstream apps may not, so Exim can
160 detect and reject if those characters are present.
162 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
163 codepoints with valid ones.
165 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
166 command line and matching a regex against the return data for trigger
167 and a second regex to extract malware_name. The mail spoolfile name can
168 be included in the command line.
170 5. The smtp transport now supports options "tls_verify_hosts" and
171 "tls_try_verify_hosts". If either is set the certificate verification
172 is split from the encryption operation. The default remains that a failed
173 verification cancels the encryption.
175 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
176 lookup can now set a list of servers to use that is different from the
179 7. New command-line option -C for exiqgrep to specify alternate exim.conf
180 file when searching the queue.
182 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
184 9. Support for DNSSEC on outbound connections.
186 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
187 "certextract" to extract fields from them. Hash operators md5 and sha1
188 work over them for generating fingerprints, and a new sha256 operator
191 11. PRDR is now supported dy default.
193 12. OCSP stapling is now supported by default.
195 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
196 Delivery Status Notification messages in MIME format, and negociate
197 DSN features per RFC 3461.
203 1. New command-line option -bI:sieve will list all supported sieve extensions
204 of this Exim build on standard output, one per line.
205 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
206 query this to establish the correct list to include in the protocol's
207 SIEVE capability line.
209 2. If the -n option is combined with the -bP option, then the name of an
210 emitted option is not output, only the value (if visible to you).
211 For instance, "exim -n -bP pid_file_path" should just emit a pathname
212 followed by a newline, and no other text.
214 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
215 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
216 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
217 acceptable for security. (Option accepted but ignored if using OpenSSL).
218 Defaults to 1024, the old value. May be lowered only to 512, or raised as
219 far as you like. Raising this may hinder TLS interoperability with other
220 sites and is not currently recommended. Lowering this will permit you to
221 establish a TLS session which is not as secure as you might like.
223 Unless you really know what you are doing, leave it alone.
225 4. If not built with DISABLE_DNSSEC, Exim now has the main option
226 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
227 to send the DO flag to your recursive resolver. If you have a recursive
228 resolver, which can set the Authenticated Data (AD) flag in results, Exim
229 can now detect this. Exim does not perform validation itself, instead
230 relying upon a trusted path to the resolver.
232 Current status: work-in-progress; $sender_host_dnssec variable added.
234 5. DSCP support for outbound connections: on a transport using the smtp driver,
235 set "dscp = ef", for instance, to cause the connections to have the relevant
236 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
238 Similarly for inbound connections, there is a new control modifier, dscp,
239 so "warn control = dscp/ef" in the connect ACL, or after authentication.
241 Supported values depend upon system libraries. "exim -bI:dscp" to list the
242 ones Exim knows of. You can also set a raw number 0..0x3F.
244 6. The -G command-line flag is no longer ignored; it is now equivalent to an
245 ACL setting "control = suppress_local_fixups". The -L command-line flag
246 is now accepted and forces use of syslog, with the provided tag as the
247 process name. A few other flags used by Sendmail are now accepted and
250 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
251 ACL modifier; works for single-recipient mails which are recieved on and
252 deliverable via SMTP. Using the connection made for a recipient verify,
253 if requested before the verify, or a new one made for the purpose while
254 the inbound connection is still active. The bulk of the mail item is copied
255 direct from the inbound socket to the outbound (as well as the spool file).
256 When the source notifies the end of data, the data acceptance by the destination
257 is negociated before the acceptance is sent to the source. If the destination
258 does not accept the mail item, for example due to content-scanning, the item
259 is not accepted from the source and therefore there is no need to generate
260 a bounce mail. This is of benefit when providing a secondary-MX service.
261 The downside is that delays are under the control of the ultimate destination
264 The Recieved-by: header on items delivered by cutthrough is generated
265 early in reception rather than at the end; this will affect any timestamp
266 included. The log line showing delivery is recorded before that showing
267 reception; it uses a new ">>" tag instead of "=>".
269 To support the feature, verify-callout connections can now use ESMTP and TLS.
270 The usual smtp transport options are honoured, plus a (new, default everything)
271 hosts_verify_avoid_tls.
273 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
274 for specific access to the information for each connection. The old names
275 are present for now but deprecated.
277 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
279 8. New expansion operators ${listnamed:name} to get the content of a named list
280 and ${listcount:string} to count the items in a list.
282 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
283 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
284 modules. For some situations this is desirable, but we expect admin in
285 those situations to know they want the feature. More commonly, it means
286 that GUI user modules get loaded and are broken by the setuid Exim being
287 unable to access files specified in environment variables and passed
288 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
289 unless this new option is set.
291 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
292 so have also added a build option which can be used to build Exim with GnuTLS
293 but without trying to use any kind of PKCS11 support. Uncomment this in the
296 AVOID_GNUTLS_PKCS11=yes
298 10. The "acl = name" condition on an ACL now supports optional arguments.
299 New expansion item "${acl {name}{arg}...}" and expansion condition
300 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
301 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
302 Variable $acl_narg contains the number of arguments. If the ACL sets
303 a "message =" value this becomes the result of the expansion item,
304 or the value of $value for the expansion condition. If the ACL returns
305 accept the expansion condition is true; if reject, false. A defer
306 return results in a forced fail.
308 11. Routers and transports can now have multiple headers_add and headers_remove
309 option lines. The concatenated list is used.
311 12. New ACL modifier "remove_header" can remove headers before message gets
312 handled by routers/transports.
314 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
315 "aaaa" and "a" lookups is done and the full set of results returned.
317 14. New expansion variable $headers_added with content from ACL add_header
318 modifier (but not yet added to message).
320 15. New 8bitmime status logging option for received messages. Log field "M8S".
322 16. New authenticated_sender logging option, adding to log field "A".
324 17. New expansion variables $router_name and $transport_name. Useful
325 particularly for debug_print as -bt commandline option does not
326 require privilege whereas -d does.
328 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
329 proposed extension to SMTP from Eric Hall.
331 19. The pipe transport has gained the force_command option, to allow
332 decorating commands from user .forward pipe aliases with prefix
333 wrappers, for instance.
335 20. Callout connections can now AUTH; the same controls as normal delivery
338 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
339 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
340 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
341 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
342 dmarc_status. It adds new control flags dmarc_disable_verify and
343 dmarc_enable_forensic.
345 22. Add expansion variable $authenticated_fail_id, which is the username
346 provided to the authentication method which failed. It is available
347 for use in subsequent ACL processing (typically quit or notquit ACLs).
349 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
352 24. New ${hexquote:..string..} expansion operator converts non-printable
353 characters in the string to \xNN form.
355 25. Experimental TPDA (Transport Post Delivery Action) function added.
356 Patch provided by Axel Rau.
358 26. Experimental Redis lookup added. Patch provided by Warren Baker.
364 1. New authenticator driver, "gsasl". Server-only (at present).
365 This is a SASL interface, licensed under GPL, which can be found at
366 http://www.gnu.org/software/gsasl/.
367 This system does not provide sources of data for authentication, so
368 careful use needs to be made of the conditions in Exim.
370 2. New authenticator driver, "heimdal_gssapi". Server-only.
371 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
372 is no longer honoured for setuid programs by Heimdal. Use the
373 "server_keytab" option to point to the keytab.
375 3. The "pkg-config" system can now be used when building Exim to reference
376 cflags and library information for lookups and authenticators, rather
377 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
378 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
379 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
381 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
382 find the headers and libraries for PCRE.
384 4. New expansion variable $tls_bits.
386 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
387 be joined together with ASCII NUL characters to construct the key to pass
388 into the DBM library. Can be used with gsasl to access sasldb2 files as
391 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
393 Avoid release 1.0.1a if you can. Note that the default value of
394 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
395 increased susceptibility to attack. This may still have interoperability
396 implications for very old clients (see version 4.31 change 37) but
397 administrators can choose to make the trade-off themselves and restore
398 compatibility at the cost of session security.
400 7. Use of the new expansion variable $tls_sni in the main configuration option
401 tls_certificate will cause Exim to re-expand the option, if the client
402 sends the TLS Server Name Indication extension, to permit choosing a
403 different certificate; tls_privatekey will also be re-expanded. You must
404 still set these options to expand to valid files when $tls_sni is not set.
406 The SMTP Transport has gained the option tls_sni, which will set a hostname
407 for outbound TLS sessions, and set $tls_sni too.
409 A new log_selector, +tls_sni, has been added, to log received SNI values
410 for Exim as a server.
412 8. The existing "accept_8bitmime" option now defaults to true. This means
413 that Exim is deliberately not strictly RFC compliant. We're following
414 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
415 Those who disagree, or know that they are talking to mail servers that,
416 even today, are not 8-bit clean, need to turn off this option.
418 9. Exim can now be started with -bw (with an optional timeout, given as
419 -bw<timespec>). With this, stdin at startup is a socket that is
420 already listening for connections. This has a more modern name of
421 "socket activation", but forcing the activated socket to fd 0. We're
422 interested in adding more support for modern variants.
424 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
425 for numbers indicates multiplication by 1024^3.
427 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
428 gnutls_require_mac & gnutls_require_protocols are no longer supported.
429 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
430 string, documentation for which is at:
431 http://www.gnutls.org/manual/html_node/Priority-Strings.html
433 SNI support has been added to Exim's GnuTLS integration too.
435 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
436 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
438 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
439 is now available. If the contents of the file are valid, then Exim will
440 send that back in response to a TLS status request; this is OCSP Stapling.
441 Exim will not maintain the contents of the file in any way: administrators
442 are responsible for ensuring that it is up-to-date.
444 See "experimental-spec.txt" for more details.
446 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
447 identically to TXT record lookups.
449 14. New expansion variable $tod_epoch_l for higher-precision time.
451 15. New global option tls_dh_max_bits, defaulting to current value of NSS
452 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
453 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
455 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
456 Option can now be a path or an identifier for a standard prime.
457 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
458 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
461 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
462 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
463 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
469 1. New options for the ratelimit ACL condition: /count= and /unique=.
470 The /noupdate option has been replaced by a /readonly option.
472 2. The SMTP transport's protocol option may now be set to "smtps", to
473 use SSL-on-connect outbound.
475 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
476 there is a problem talking to the AV scanner, or the AV scanner running.
478 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
479 and check if the search item is a member of the list. This does not
480 support named lists, but does subject the list part to string expansion.
482 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
483 built, Exim no longer performs string expansion on the second string of
484 the match_* expansion conditions: "match_address", "match_domain",
485 "match_ip" & "match_local_part". Named lists can still be used.
491 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
492 or off in the resolver library.
498 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
499 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
500 libraries. The following global options have been added in support of
501 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
502 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
504 2. The pipe transport now takes a boolean option, "freeze_signal", default
505 false. When true, if the external delivery command exits on a signal then
506 Exim will freeze the message in the queue, instead of generating a bounce.
508 3. Log filenames may now use %M as an escape, instead of %D (still available).
509 The %M pattern expands to yyyymm, providing month-level resolution.
511 4. The $message_linecount variable is now updated for the maildir_tag option,
512 in the same way as $message_size, to reflect the real number of lines,
513 including any header additions or removals from transport.
515 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
516 Exim now selects entries randomly, to better scale in a cluster setup.
522 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
523 the flaw permitted the Exim run-time user to cause root to append to
524 arbitrary files of the attacker's choosing, with the content based
525 on content supplied by the attacker.
527 2. Exim now supports loading some lookup types at run-time, using your
528 platform's dlopen() functionality. This has limited platform support
529 and the intention is not to support every variant, it's limited to
530 dlopen(). This permits the main Exim binary to not be linked against
531 all the libraries needed for all the lookup types.
537 NOTE: this version is not guaranteed backwards-compatible, please read the
538 items below carefully
540 1. A new main configuration option, "openssl_options", is available if Exim
541 is built with SSL support provided by OpenSSL. The option allows
542 administrators to specify OpenSSL options to be used on connections;
543 typically this is to set bug compatibility features which the OpenSSL
544 developers have not enabled by default. There may be security
545 consequences for certain options, so these should not be changed
548 2. A new pipe transport option, "permit_coredumps", may help with problem
549 diagnosis in some scenarios. Note that Exim is typically installed as
550 a setuid binary, which on most OSes will inhibit coredumps by default,
551 so that safety mechanism would have to be overridden for this option to
552 be able to take effect.
554 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
555 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
556 Note that this switches Exim to use a new API ("INSTREAM") and a future
557 release of ClamAV will remove support for the old API ("STREAM").
559 The av_scanner option, when set to "clamd", now takes an optional third
560 part, "local", which causes Exim to pass a filename to ClamAV instead of
561 the file content. This is the same behaviour as when clamd is pointed at
562 a Unix-domain socket. For example:
564 av_scanner = clamd:192.0.2.3 1234:local
566 ClamAV's ExtendedDetectionInfo response format is now handled.
568 4. There is now a -bmalware option, restricted to admin users. This option
569 takes one parameter, a filename, and scans that file with Exim's
570 malware-scanning framework. This is intended purely as a debugging aid
571 to ensure that Exim's scanning is working, not to replace other tools.
572 Note that the ACL framework is not invoked, so if av_scanner references
573 ACL variables without a fallback then this will fail.
575 5. There is a new expansion operator, "reverse_ip", which will reverse IP
576 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
578 ${reverse_ip:192.0.2.4}
580 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
581 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
583 6. There is a new ACL control called "debug", to enable debug logging.
584 This allows selective logging of certain incoming transactions within
585 production environments, with some care. It takes two options, "tag"
586 and "opts"; "tag" is included in the filename of the log and "opts"
587 is used as per the -d<options> command-line option. Examples, which
588 don't all make sense in all contexts:
591 control = debug/tag=.$sender_host_address
592 control = debug/opts=+expand+acl
593 control = debug/tag=.$message_exim_id/opts=+expand
595 7. It has always been implicit in the design and the documentation that
596 "the Exim user" is not root. src/EDITME said that using root was
597 "very strongly discouraged". This is not enough to keep people from
598 shooting themselves in the foot in days when many don't configure Exim
599 themselves but via package build managers. The security consequences of
600 running various bits of network code are severe if there should be bugs in
601 them. As such, the Exim user may no longer be root. If configured
602 statically, Exim will refuse to build. If configured as ref:user then Exim
603 will exit shortly after start-up. If you must shoot yourself in the foot,
604 then henceforth you will have to maintain your own local patches to strip
607 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
608 condition logic to determine truth/failure and will fail to expand many
609 strings, bool_lax{} uses the router condition logic, where most strings
611 Note: bool{00} is false, bool_lax{00} is true.
613 9. Routers now support multiple "condition" tests.
615 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
616 Setting this allows an admin to define which entry in the tcpwrappers
617 config file will be used to control access to the daemon. This option
618 is only available when Exim is built with USE_TCP_WRAPPERS. The
619 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
622 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
623 the Exim run-time user, instead of root.
625 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
626 is forced on. This is mitigated by the new build option
627 TRUSTED_CONFIG_LIST which defines a list of configuration files which
628 are trusted; one per line. If a config file is owned by root and matches
629 a pathname in the list, then it may be invoked by the Exim build-time
630 user without Exim relinquishing root privileges.
632 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
633 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
634 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
635 include the main config. As a transition mechanism, we are temporarily
636 providing a work-around: the new build option WHITELIST_D_MACROS provides
637 a colon-separated list of macro names which may be overridden by the Exim
638 run-time user. The values of these macros are constrained to the regex
639 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
645 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
646 writable, the other to locking of MBX folders (not mbox).
648 2. MySQL stored procedures are now supported.
650 3. The dkim_domain transport option is now a list, not a single string, and
651 messages will be signed for each element in the list (discarding
654 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
655 in the presence of multiple character strings within the RR. Prior to 4.70,
656 only the first string would be returned. The dnsdb lookup now, by default,
657 preserves the pre-4.70 semantics, but also now takes an extended output
658 separator specification. The separator can be followed by a semicolon, to
659 concatenate the individual text strings together with no join character,
660 or by a comma and a second separator character, in which case the text
661 strings within a TXT record are joined on that second character.
662 Administrators are reminded that DNS provides no ordering guarantees
663 between multiple records in an RRset. For example:
665 foo.example. IN TXT "a" "b" "c"
666 foo.example. IN TXT "d" "e" "f"
668 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
669 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
670 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
676 1. Native DKIM support without an external library.
677 (Note that if no action to prevent it is taken, a straight upgrade will
678 result in DKIM verification of all signed incoming emails. See spec
679 for details on conditionally disabling)
681 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
683 3. There is now a bool{} expansion condition which maps certain strings to
684 true/false condition values (most likely of use in conjunction with the
685 and{} expansion operator).
687 4. The $spam_score, $spam_bar and $spam_report variables are now available
690 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
691 options, provided that Exim is invoked by an admin_user.
693 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
694 which increases compatibility with older clients at the cost of decreased
695 security. Don't set this unless you need to support such clients.
697 7. There is a new expansion operator, ${randint:...} which will produce a
698 "random" number less than the supplied integer. This randomness is
699 not guaranteed to be cryptographically strong, but depending upon how
700 Exim was built may be better than the most naive schemes.
702 8. Exim now explicitly ensures that SHA256 is available when linked against
705 9. The transport_filter_timeout option now applies to SMTP transports too.
711 1. Preliminary DKIM support in Experimental.
717 1. The body_linecount and body_zerocount C variables are now exported in the
720 2. When a dnslists lookup succeeds, the key that was looked up is now placed
721 in $dnslist_matched. When the key is an IP address, it is not reversed in
722 this variable (though it is, of course, in the actual lookup). In simple
725 deny dnslists = spamhaus.example
727 the key is also available in another variable (in this case,
728 $sender_host_address). In more complicated cases, however, this is not
729 true. For example, using a data lookup might generate a dnslists lookup
732 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
734 If this condition succeeds, the value in $dnslist_matched might be
735 192.168.6.7 (for example).
737 3. Authenticators now have a client_condition option. When Exim is running as
738 a client, it skips an authenticator whose client_condition expansion yields
739 "0", "no", or "false". This can be used, for example, to skip plain text
740 authenticators when the connection is not encrypted by a setting such as:
742 client_condition = ${if !eq{$tls_cipher}{}}
744 Note that the 4.67 documentation states that $tls_cipher contains the
745 cipher used for incoming messages. In fact, during SMTP delivery, it
746 contains the cipher used for the delivery. The same is true for
749 4. There is now a -Mvc <message-id> option, which outputs a copy of the
750 message to the standard output, in RFC 2822 format. The option can be used
751 only by an admin user.
753 5. There is now a /noupdate option for the ratelimit ACL condition. It
754 computes the rate and checks the limit as normal, but it does not update
755 the saved data. This means that, in relevant ACLs, it is possible to lookup
756 the existence of a specified (or auto-generated) ratelimit key without
757 incrementing the ratelimit counter for that key.
759 In order for this to be useful, another ACL entry must set the rate
760 for the same key somewhere (otherwise it will always be zero).
765 # Read the rate; if it doesn't exist or is below the maximum
767 deny ratelimit = 100 / 5m / strict / noupdate
768 log_message = RATE: $sender_rate / $sender_rate_period \
769 (max $sender_rate_limit)
771 [... some other logic and tests...]
773 warn ratelimit = 100 / 5m / strict / per_cmd
774 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
775 (max $sender_rate_limit)
776 condition = ${if le{$sender_rate}{$sender_rate_limit}}
780 6. The variable $max_received_linelength contains the number of bytes in the
781 longest line that was received as part of the message, not counting the
782 line termination character(s).
784 7. Host lists can now include +ignore_defer and +include_defer, analagous to
785 +ignore_unknown and +include_unknown. These options should be used with
786 care, probably only in non-critical host lists such as whitelists.
788 8. There's a new option called queue_only_load_latch, which defaults true.
789 If set false when queue_only_load is greater than zero, Exim re-evaluates
790 the load for each incoming message in an SMTP session. Otherwise, once one
791 message is queued, the remainder are also.
793 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
794 cases when an SMTP session ends without sending QUIT. However, when Exim
795 itself is is bad trouble, such as being unable to write to its log files,
796 this ACL is not run, because it might try to do things (such as write to
797 log files) that make the situation even worse.
799 Like the QUIT ACL, this new ACL is provided to make it possible to gather
800 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
801 modifier is forbidden in this ACL.
803 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
804 to a string that indicates the reason for the termination of the SMTP
805 connection. The possible values are:
807 acl-drop Another ACL issued a "drop" command
808 bad-commands Too many unknown or non-mail commands
809 command-timeout Timeout while reading SMTP commands
810 connection-lost The SMTP connection has been lost
811 data-timeout Timeout while reading message data
812 local-scan-error The local_scan() function crashed
813 local-scan-timeout The local_scan() function timed out
814 signal-exit SIGTERM or SIGINT
815 synchronization-error SMTP synchronization error
816 tls-failed TLS failed to start
818 In most cases when an SMTP connection is closed without having received
819 QUIT, Exim sends an SMTP response message before actually closing the
820 connection. With the exception of acl-drop, the default message can be
821 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
822 "drop" verb in another ACL, it is the message from the other ACL that is
825 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
826 servers with individual queries. This is done by starting the query with
827 "servers=x:y:z;", where each item in the list may take one of two forms:
829 (1) If it is just a host name, the appropriate global option (mysql_servers
830 or pgsql_servers) is searched for a host of the same name, and the
831 remaining parameters (database, user, password) are taken from there.
833 (2) If it contains any slashes, it is taken as a complete parameter set.
835 The list of servers is used in exactly the same was as the global list.
836 Once a connection to a server has happened and a query has been
837 successfully executed, processing of the lookup ceases.
839 This feature is intended for use in master/slave situations where updates
840 are occurring, and one wants to update a master rather than a slave. If the
841 masters are in the list for reading, you might have:
843 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
845 In an updating lookup, you could then write
847 ${lookup mysql{servers=master; UPDATE ...}
849 If, on the other hand, the master is not to be used for reading lookups:
851 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
853 you can still update the master by
855 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
857 11. The message_body_newlines option (default FALSE, for backwards
858 compatibility) can be used to control whether newlines are present in
859 $message_body and $message_body_end. If it is FALSE, they are replaced by
866 1. There is a new log selector called smtp_no_mail, which is not included in
867 the default setting. When it is set, a line is written to the main log
868 whenever an accepted SMTP connection terminates without having issued a
871 2. When an item in a dnslists list is followed by = and & and a list of IP
872 addresses, the behaviour was not clear when the lookup returned more than
873 one IP address. This has been solved by the addition of == and =& for "all"
874 rather than the default "any" matching.
876 3. Up till now, the only control over which cipher suites GnuTLS uses has been
877 for the cipher algorithms. New options have been added to allow some of the
878 other parameters to be varied.
880 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
881 set, Exim compiles a runtime option called disable_fsync.
883 5. There is a new variable called $smtp_count_at_connection_start.
885 6. There's a new control called no_pipelining.
887 7. There are two new variables called $sending_ip_address and $sending_port.
888 These are set whenever an SMTP connection to another host has been set up.
890 8. The expansion of the helo_data option in the smtp transport now happens
891 after the connection to the server has been made.
893 9. There is a new expansion operator ${rfc2047d: that decodes strings that
894 are encoded as per RFC 2047.
896 10. There is a new log selector called "pid", which causes the current process
897 id to be added to every log line, in square brackets, immediately after the
900 11. Exim has been modified so that it flushes SMTP output before implementing
901 a delay in an ACL. It also flushes the output before performing a callout,
902 as this can take a substantial time. These behaviours can be disabled by
903 obeying control = no_delay_flush or control = no_callout_flush,
904 respectively, at some earlier stage of the connection.
906 12. There are two new expansion conditions that iterate over a list. They are
907 called forany and forall.
909 13. There's a new global option called dsn_from that can be used to vary the
910 contents of From: lines in bounces and other automatically generated
911 messages ("delivery status notifications" - hence the name of the option).
913 14. The smtp transport has a new option called hosts_avoid_pipelining.
915 15. By default, exigrep does case-insensitive matches. There is now a -I option
916 that makes it case-sensitive.
918 16. A number of new features ("addresses", "map", "filter", and "reduce") have
919 been added to string expansions to make it easier to process lists of
920 items, typically addresses.
922 17. There's a new ACL modifier called "continue". It does nothing of itself,
923 and processing of the ACL always continues with the next condition or
924 modifier. It is provided so that the side effects of expanding its argument
927 18. It is now possible to use newline and other control characters (those with
928 values less than 32, plus DEL) as separators in lists.
930 19. The exigrep utility now has a -v option, which inverts the matching
933 20. The host_find_failed option in the manualroute router can now be set to
940 No new features were added to 4.66.
946 No new features were added to 4.65.
952 1. ACL variables can now be given arbitrary names, as long as they start with
953 "acl_c" or "acl_m" (for connection variables and message variables), are at
954 least six characters long, with the sixth character being either a digit or
957 2. There is a new ACL modifier called log_reject_target. It makes it possible
958 to specify which logs are used for messages about ACL rejections.
960 3. There is a new authenticator called "dovecot". This is an interface to the
961 authentication facility of the Dovecot POP/IMAP server, which can support a
962 number of authentication methods.
964 4. The variable $message_headers_raw provides a concatenation of all the
965 messages's headers without any decoding. This is in contrast to
966 $message_headers, which does RFC2047 decoding on the header contents.
968 5. In a DNS black list, if two domain names, comma-separated, are given, the
969 second is used first to do an initial check, making use of any IP value
970 restrictions that are set. If there is a match, the first domain is used,
971 without any IP value restrictions, to get the TXT record.
973 6. All authenticators now have a server_condition option.
975 7. There is a new command-line option called -Mset. It is useful only in
976 conjunction with -be (that is, when testing string expansions). It must be
977 followed by a message id; Exim loads the given message from its spool
978 before doing the expansions.
980 8. Another similar new command-line option is called -bem. It operates like
981 -be except that it must be followed by the name of a file that contains a
984 9. When an address is delayed because of a 4xx response to a RCPT command, it
985 is now the combination of sender and recipient that is delayed in
986 subsequent queue runs until its retry time is reached.
988 10. Unary negation and the bitwise logical operators and, or, xor, not, and
989 shift, have been added to the eval: and eval10: expansion items.
991 11. The variables $interface_address and $interface_port have been renamed
992 as $received_ip_address and $received_port, to make it clear that they
993 relate to message reception rather than delivery. (The old names remain
994 available for compatibility.)
996 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
997 to vary the message that is sent when an SMTP command is accepted.
1003 1. There is a new Boolean option called filter_prepend_home for the redirect
1006 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
1007 start of receiving a non-SMTP message, before any of the message has been
1010 3. When an SMTP error message is specified in a "message" modifier in an ACL,
1011 or in a :fail: or :defer: message in a redirect router, Exim now checks the
1012 start of the message for an SMTP error code.
1014 4. There is a new parameter for LDAP lookups called "referrals", which takes
1015 one of the settings "follow" (the default) or "nofollow".
1017 5. Version 20070721.2 of exipick now included, offering these new options:
1019 After all other sorting options have bee processed, reverse order
1020 before displaying messages (-R is synonym).
1022 Randomize order of matching messages before displaying.
1024 Instead of displaying the matching messages, display the sum
1026 --sort <variable>[,<variable>...]
1027 Before displaying matching messages, sort the messages according to
1028 each messages value for each variable.
1030 Negate the value for every test (returns inverse output from the
1031 same criteria without --not).
1037 1. The ${readsocket expansion item now supports Internet domain sockets as well
1038 as Unix domain sockets. If the first argument begins "inet:", it must be of
1039 the form "inet:host:port". The port is mandatory; it may be a number or the
1040 name of a TCP port in /etc/services. The host may be a name, or it may be an
1041 IP address. An ip address may optionally be enclosed in square brackets.
1042 This is best for IPv6 addresses. For example:
1044 ${readsocket{inet:[::1]:1234}{<request data>}...
1046 Only a single host name may be given, but if looking it up yield more than
1047 one IP address, they are each tried in turn until a connection is made. Once
1048 a connection has been made, the behaviour is as for ${readsocket with a Unix
1051 2. If a redirect router sets up file or pipe deliveries for more than one
1052 incoming address, and the relevant transport has batch_max set greater than
1053 one, a batch delivery now occurs.
1055 3. The appendfile transport has a new option called maildirfolder_create_regex.
1056 Its value is a regular expression. For a maildir delivery, this is matched
1057 against the maildir directory; if it matches, Exim ensures that a
1058 maildirfolder file is created alongside the new, cur, and tmp directories.
1064 The documentation is up-to-date for the 4.61 release. Major new features since
1065 the 4.60 release are:
1067 . An option called disable_ipv6, to disable the use of IPv6 completely.
1069 . An increase in the number of ACL variables to 20 of each type.
1071 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
1072 $2, $3, (though those are still set) because the numeric variables get used
1073 for other things in complicated expansions.
1075 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1077 . It is possible to use setclassresources() on some BSD OS to control the
1078 resources used in pipe deliveries.
1080 . A new ACL modifier called add_header, which can be used with any verb.
1082 . More errors are detectable in retry rules.
1084 There are a number of other additions too.
1090 The documentation is up-to-date for the 4.60 release. Major new features since
1091 the 4.50 release are:
1093 . Support for SQLite.
1095 . Support for IGNOREQUOTA in LMTP.
1097 . Extensions to the "submission mode" features.
1099 . Support for Client SMTP Authorization (CSA).
1101 . Support for ratelimiting hosts and users.
1103 . New expansion items to help with the BATV "prvs" scheme.
1105 . A "match_ip" condition, that matches an IP address against a list.
1107 There are many more minor changes.
git://git.exim.org / exim.git / blob