4 This file contains descriptions of new features that have been added to Exim.
5 Before a formal release, there may be quite a lot of detail so that people can
6 test from the snapshots or the CVS before the documentation is updated. Once
7 the documentation is updated, this file is reduced to a short list.
12 1. The new perl_tainmode option allows to run the embedded perl
13 interpreter in taint mode.
15 2. Facility for named queues: A commandline argument can specify
16 the queue name for a queue-runner, and an ACL modifier can set
17 the queue to be used for a message. A $queue_name variable gives
24 1. The ACL conditions regex and mime_regex now capture substrings
25 into numeric variables $regex1 to 9, like the "match" expansion condition.
27 2. New $callout_address variable records the address used for a spam=,
28 malware= or verify= callout.
30 3. Transports now take a "max_parallel" option, to limit concurrency.
32 4. Expansion operators ${ipv6norm:<string>} and ${ipv6denorm:<string>}.
33 The latter expands to a 8-element colon-sep set of hex digits including
34 leading zeroes. A trailing ipv4-style dotted-decimal set is converted
35 to hex. Pure ipv4 addresses are converted to IPv4-mapped IPv6.
36 The former operator strips leading zeroes and collapses the longest
37 set of 0-groups to a double-colon.
39 5. New "-bP config" support, to dump the effective configuration.
41 6. New $dkim_key_length variable.
43 7. New base64d and base64 expansion items (the existing str2b64 being a
44 synonym of the latter). Add support in base64 for certificates.
46 8. New main configuration option "bounce_return_linesize_limit" to
47 avoid oversize bodies in bounces. The dafault value matches RFC
50 9. New $initial_cwd expansion variable.
56 1. Support for using the system standard CA bundle.
58 2. New expansion items $config_file, $config_dir, containing the file
59 and directory name of the main configuration file. Also $exim_version.
61 3. New "malware=" support for Avast.
63 4. New "spam=" variant option for Rspamd.
65 5. Assorted options on malware= and spam= scanners.
67 6. A commandline option to write a comment into the logfile.
69 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
70 be configured to make connections via socks5 proxies.
72 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
73 the transmission of UTF-8 envelope addresses.
75 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
76 used encoding of Maildir folder names.
78 10. A logging option for slow DNS lookups.
80 11. New ${env {<variable>}} expansion.
82 12. A non-SMTP authenticator using information from TLS client certificates.
84 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
85 Patch originally by Wolfgang Breyha.
87 14. Main option "dns_trust_aa" for trusting your local nameserver at the
94 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
95 DANE smtp draft to assess a secure chain of trust of the certificate
96 used to establish the TLS connection based on a TLSA record in the
99 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
100 and several new events have been created. The reason is because it has
101 been expanded beyond just firing events during the transport phase. Any
102 existing TPDA transport options will have to be rewritten to use a new
103 $event_name expansion variable in a condition. Refer to the
104 experimental-spec.txt for details and examples.
106 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
107 server certs used for TLS match the result of the MX lookup. It does
108 not use the same mechanism as DANE.
118 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
119 configured to expect an initial header from a proxy that will make the
120 actual external source IP:host be used in exim instead of the IP of the
121 proxy that is connecting to it.
123 2. New verify option header_names_ascii, which will check to make sure
124 there are no non-ASCII characters in header names. Exim itself handles
125 those non-ASCII characters, but downstream apps may not, so Exim can
126 detect and reject if those characters are present.
128 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
129 codepoints with valid ones.
131 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
132 command line and matching a regex against the return data for trigger
133 and a second regex to extract malware_name. The mail spoolfile name can
134 be included in the command line.
136 5. The smtp transport now supports options "tls_verify_hosts" and
137 "tls_try_verify_hosts". If either is set the certificate verification
138 is split from the encryption operation. The default remains that a failed
139 verification cancels the encryption.
141 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
142 lookup can now set a list of servers to use that is different from the
145 7. New command-line option -C for exiqgrep to specify alternate exim.conf
146 file when searching the queue.
148 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
150 9. Support for DNSSEC on outbound connections.
152 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
153 "certextract" to extract fields from them. Hash operators md5 and sha1
154 work over them for generating fingerprints, and a new sha256 operator
157 11. PRDR is now supported dy default.
159 12. OCSP stapling is now supported by default.
161 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
162 Delivery Status Notification messages in MIME format, and negociate
163 DSN features per RFC 3461.
169 1. New command-line option -bI:sieve will list all supported sieve extensions
170 of this Exim build on standard output, one per line.
171 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
172 query this to establish the correct list to include in the protocol's
173 SIEVE capability line.
175 2. If the -n option is combined with the -bP option, then the name of an
176 emitted option is not output, only the value (if visible to you).
177 For instance, "exim -n -bP pid_file_path" should just emit a pathname
178 followed by a newline, and no other text.
180 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
181 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
182 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
183 acceptable for security. (Option accepted but ignored if using OpenSSL).
184 Defaults to 1024, the old value. May be lowered only to 512, or raised as
185 far as you like. Raising this may hinder TLS interoperability with other
186 sites and is not currently recommended. Lowering this will permit you to
187 establish a TLS session which is not as secure as you might like.
189 Unless you really know what you are doing, leave it alone.
191 4. If not built with DISABLE_DNSSEC, Exim now has the main option
192 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
193 to send the DO flag to your recursive resolver. If you have a recursive
194 resolver, which can set the Authenticated Data (AD) flag in results, Exim
195 can now detect this. Exim does not perform validation itself, instead
196 relying upon a trusted path to the resolver.
198 Current status: work-in-progress; $sender_host_dnssec variable added.
200 5. DSCP support for outbound connections: on a transport using the smtp driver,
201 set "dscp = ef", for instance, to cause the connections to have the relevant
202 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
204 Similarly for inbound connections, there is a new control modifier, dscp,
205 so "warn control = dscp/ef" in the connect ACL, or after authentication.
207 Supported values depend upon system libraries. "exim -bI:dscp" to list the
208 ones Exim knows of. You can also set a raw number 0..0x3F.
210 6. The -G command-line flag is no longer ignored; it is now equivalent to an
211 ACL setting "control = suppress_local_fixups". The -L command-line flag
212 is now accepted and forces use of syslog, with the provided tag as the
213 process name. A few other flags used by Sendmail are now accepted and
216 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
217 ACL modifier; works for single-recipient mails which are recieved on and
218 deliverable via SMTP. Using the connection made for a recipient verify,
219 if requested before the verify, or a new one made for the purpose while
220 the inbound connection is still active. The bulk of the mail item is copied
221 direct from the inbound socket to the outbound (as well as the spool file).
222 When the source notifies the end of data, the data acceptance by the destination
223 is negociated before the acceptance is sent to the source. If the destination
224 does not accept the mail item, for example due to content-scanning, the item
225 is not accepted from the source and therefore there is no need to generate
226 a bounce mail. This is of benefit when providing a secondary-MX service.
227 The downside is that delays are under the control of the ultimate destination
230 The Recieved-by: header on items delivered by cutthrough is generated
231 early in reception rather than at the end; this will affect any timestamp
232 included. The log line showing delivery is recorded before that showing
233 reception; it uses a new ">>" tag instead of "=>".
235 To support the feature, verify-callout connections can now use ESMTP and TLS.
236 The usual smtp transport options are honoured, plus a (new, default everything)
237 hosts_verify_avoid_tls.
239 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
240 for specific access to the information for each connection. The old names
241 are present for now but deprecated.
243 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
245 8. New expansion operators ${listnamed:name} to get the content of a named list
246 and ${listcount:string} to count the items in a list.
248 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
249 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
250 modules. For some situations this is desirable, but we expect admin in
251 those situations to know they want the feature. More commonly, it means
252 that GUI user modules get loaded and are broken by the setuid Exim being
253 unable to access files specified in environment variables and passed
254 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
255 unless this new option is set.
257 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
258 so have also added a build option which can be used to build Exim with GnuTLS
259 but without trying to use any kind of PKCS11 support. Uncomment this in the
262 AVOID_GNUTLS_PKCS11=yes
264 10. The "acl = name" condition on an ACL now supports optional arguments.
265 New expansion item "${acl {name}{arg}...}" and expansion condition
266 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
267 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
268 Variable $acl_narg contains the number of arguments. If the ACL sets
269 a "message =" value this becomes the result of the expansion item,
270 or the value of $value for the expansion condition. If the ACL returns
271 accept the expansion condition is true; if reject, false. A defer
272 return results in a forced fail.
274 11. Routers and transports can now have multiple headers_add and headers_remove
275 option lines. The concatenated list is used.
277 12. New ACL modifier "remove_header" can remove headers before message gets
278 handled by routers/transports.
280 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
281 "aaaa" and "a" lookups is done and the full set of results returned.
283 14. New expansion variable $headers_added with content from ACL add_header
284 modifier (but not yet added to message).
286 15. New 8bitmime status logging option for received messages. Log field "M8S".
288 16. New authenticated_sender logging option, adding to log field "A".
290 17. New expansion variables $router_name and $transport_name. Useful
291 particularly for debug_print as -bt commandline option does not
292 require privilege whereas -d does.
294 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
295 proposed extension to SMTP from Eric Hall.
297 19. The pipe transport has gained the force_command option, to allow
298 decorating commands from user .forward pipe aliases with prefix
299 wrappers, for instance.
301 20. Callout connections can now AUTH; the same controls as normal delivery
304 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
305 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
306 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
307 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
308 dmarc_status. It adds new control flags dmarc_disable_verify and
309 dmarc_enable_forensic.
311 22. Add expansion variable $authenticated_fail_id, which is the username
312 provided to the authentication method which failed. It is available
313 for use in subsequent ACL processing (typically quit or notquit ACLs).
315 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
318 24. New ${hexquote:..string..} expansion operator converts non-printable
319 characters in the string to \xNN form.
321 25. Experimental TPDA (Transport Post Delivery Action) function added.
322 Patch provided by Axel Rau.
324 26. Experimental Redis lookup added. Patch provided by Warren Baker.
330 1. New authenticator driver, "gsasl". Server-only (at present).
331 This is a SASL interface, licensed under GPL, which can be found at
332 http://www.gnu.org/software/gsasl/.
333 This system does not provide sources of data for authentication, so
334 careful use needs to be made of the conditions in Exim.
336 2. New authenticator driver, "heimdal_gssapi". Server-only.
337 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
338 is no longer honoured for setuid programs by Heimdal. Use the
339 "server_keytab" option to point to the keytab.
341 3. The "pkg-config" system can now be used when building Exim to reference
342 cflags and library information for lookups and authenticators, rather
343 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
344 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
345 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
347 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
348 find the headers and libraries for PCRE.
350 4. New expansion variable $tls_bits.
352 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
353 be joined together with ASCII NUL characters to construct the key to pass
354 into the DBM library. Can be used with gsasl to access sasldb2 files as
357 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
359 Avoid release 1.0.1a if you can. Note that the default value of
360 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
361 increased susceptibility to attack. This may still have interoperability
362 implications for very old clients (see version 4.31 change 37) but
363 administrators can choose to make the trade-off themselves and restore
364 compatibility at the cost of session security.
366 7. Use of the new expansion variable $tls_sni in the main configuration option
367 tls_certificate will cause Exim to re-expand the option, if the client
368 sends the TLS Server Name Indication extension, to permit choosing a
369 different certificate; tls_privatekey will also be re-expanded. You must
370 still set these options to expand to valid files when $tls_sni is not set.
372 The SMTP Transport has gained the option tls_sni, which will set a hostname
373 for outbound TLS sessions, and set $tls_sni too.
375 A new log_selector, +tls_sni, has been added, to log received SNI values
376 for Exim as a server.
378 8. The existing "accept_8bitmime" option now defaults to true. This means
379 that Exim is deliberately not strictly RFC compliant. We're following
380 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
381 Those who disagree, or know that they are talking to mail servers that,
382 even today, are not 8-bit clean, need to turn off this option.
384 9. Exim can now be started with -bw (with an optional timeout, given as
385 -bw<timespec>). With this, stdin at startup is a socket that is
386 already listening for connections. This has a more modern name of
387 "socket activation", but forcing the activated socket to fd 0. We're
388 interested in adding more support for modern variants.
390 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
391 for numbers indicates multiplication by 1024^3.
393 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
394 gnutls_require_mac & gnutls_require_protocols are no longer supported.
395 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
396 string, documentation for which is at:
397 http://www.gnutls.org/manual/html_node/Priority-Strings.html
399 SNI support has been added to Exim's GnuTLS integration too.
401 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
402 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
404 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
405 is now available. If the contents of the file are valid, then Exim will
406 send that back in response to a TLS status request; this is OCSP Stapling.
407 Exim will not maintain the contents of the file in any way: administrators
408 are responsible for ensuring that it is up-to-date.
410 See "experimental-spec.txt" for more details.
412 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
413 identically to TXT record lookups.
415 14. New expansion variable $tod_epoch_l for higher-precision time.
417 15. New global option tls_dh_max_bits, defaulting to current value of NSS
418 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
419 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
421 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
422 Option can now be a path or an identifier for a standard prime.
423 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
424 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
427 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
428 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
429 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
435 1. New options for the ratelimit ACL condition: /count= and /unique=.
436 The /noupdate option has been replaced by a /readonly option.
438 2. The SMTP transport's protocol option may now be set to "smtps", to
439 use SSL-on-connect outbound.
441 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
442 there is a problem talking to the AV scanner, or the AV scanner running.
444 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
445 and check if the search item is a member of the list. This does not
446 support named lists, but does subject the list part to string expansion.
448 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
449 built, Exim no longer performs string expansion on the second string of
450 the match_* expansion conditions: "match_address", "match_domain",
451 "match_ip" & "match_local_part". Named lists can still be used.
457 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
458 or off in the resolver library.
464 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
465 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
466 libraries. The following global options have been added in support of
467 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
468 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
470 2. The pipe transport now takes a boolean option, "freeze_signal", default
471 false. When true, if the external delivery command exits on a signal then
472 Exim will freeze the message in the queue, instead of generating a bounce.
474 3. Log filenames may now use %M as an escape, instead of %D (still available).
475 The %M pattern expands to yyyymm, providing month-level resolution.
477 4. The $message_linecount variable is now updated for the maildir_tag option,
478 in the same way as $message_size, to reflect the real number of lines,
479 including any header additions or removals from transport.
481 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
482 Exim now selects entries randomly, to better scale in a cluster setup.
488 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
489 the flaw permitted the Exim run-time user to cause root to append to
490 arbitrary files of the attacker's choosing, with the content based
491 on content supplied by the attacker.
493 2. Exim now supports loading some lookup types at run-time, using your
494 platform's dlopen() functionality. This has limited platform support
495 and the intention is not to support every variant, it's limited to
496 dlopen(). This permits the main Exim binary to not be linked against
497 all the libraries needed for all the lookup types.
503 NOTE: this version is not guaranteed backwards-compatible, please read the
504 items below carefully
506 1. A new main configuration option, "openssl_options", is available if Exim
507 is built with SSL support provided by OpenSSL. The option allows
508 administrators to specify OpenSSL options to be used on connections;
509 typically this is to set bug compatibility features which the OpenSSL
510 developers have not enabled by default. There may be security
511 consequences for certain options, so these should not be changed
514 2. A new pipe transport option, "permit_coredumps", may help with problem
515 diagnosis in some scenarios. Note that Exim is typically installed as
516 a setuid binary, which on most OSes will inhibit coredumps by default,
517 so that safety mechanism would have to be overridden for this option to
518 be able to take effect.
520 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
521 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
522 Note that this switches Exim to use a new API ("INSTREAM") and a future
523 release of ClamAV will remove support for the old API ("STREAM").
525 The av_scanner option, when set to "clamd", now takes an optional third
526 part, "local", which causes Exim to pass a filename to ClamAV instead of
527 the file content. This is the same behaviour as when clamd is pointed at
528 a Unix-domain socket. For example:
530 av_scanner = clamd:192.0.2.3 1234:local
532 ClamAV's ExtendedDetectionInfo response format is now handled.
534 4. There is now a -bmalware option, restricted to admin users. This option
535 takes one parameter, a filename, and scans that file with Exim's
536 malware-scanning framework. This is intended purely as a debugging aid
537 to ensure that Exim's scanning is working, not to replace other tools.
538 Note that the ACL framework is not invoked, so if av_scanner references
539 ACL variables without a fallback then this will fail.
541 5. There is a new expansion operator, "reverse_ip", which will reverse IP
542 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
544 ${reverse_ip:192.0.2.4}
546 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
547 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
549 6. There is a new ACL control called "debug", to enable debug logging.
550 This allows selective logging of certain incoming transactions within
551 production environments, with some care. It takes two options, "tag"
552 and "opts"; "tag" is included in the filename of the log and "opts"
553 is used as per the -d<options> command-line option. Examples, which
554 don't all make sense in all contexts:
557 control = debug/tag=.$sender_host_address
558 control = debug/opts=+expand+acl
559 control = debug/tag=.$message_exim_id/opts=+expand
561 7. It has always been implicit in the design and the documentation that
562 "the Exim user" is not root. src/EDITME said that using root was
563 "very strongly discouraged". This is not enough to keep people from
564 shooting themselves in the foot in days when many don't configure Exim
565 themselves but via package build managers. The security consequences of
566 running various bits of network code are severe if there should be bugs in
567 them. As such, the Exim user may no longer be root. If configured
568 statically, Exim will refuse to build. If configured as ref:user then Exim
569 will exit shortly after start-up. If you must shoot yourself in the foot,
570 then henceforth you will have to maintain your own local patches to strip
573 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
574 condition logic to determine truth/failure and will fail to expand many
575 strings, bool_lax{} uses the router condition logic, where most strings
577 Note: bool{00} is false, bool_lax{00} is true.
579 9. Routers now support multiple "condition" tests.
581 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
582 Setting this allows an admin to define which entry in the tcpwrappers
583 config file will be used to control access to the daemon. This option
584 is only available when Exim is built with USE_TCP_WRAPPERS. The
585 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
588 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
589 the Exim run-time user, instead of root.
591 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
592 is forced on. This is mitigated by the new build option
593 TRUSTED_CONFIG_LIST which defines a list of configuration files which
594 are trusted; one per line. If a config file is owned by root and matches
595 a pathname in the list, then it may be invoked by the Exim build-time
596 user without Exim relinquishing root privileges.
598 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
599 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
600 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
601 include the main config. As a transition mechanism, we are temporarily
602 providing a work-around: the new build option WHITELIST_D_MACROS provides
603 a colon-separated list of macro names which may be overridden by the Exim
604 run-time user. The values of these macros are constrained to the regex
605 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
611 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
612 writable, the other to locking of MBX folders (not mbox).
614 2. MySQL stored procedures are now supported.
616 3. The dkim_domain transport option is now a list, not a single string, and
617 messages will be signed for each element in the list (discarding
620 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
621 in the presence of multiple character strings within the RR. Prior to 4.70,
622 only the first string would be returned. The dnsdb lookup now, by default,
623 preserves the pre-4.70 semantics, but also now takes an extended output
624 separator specification. The separator can be followed by a semicolon, to
625 concatenate the individual text strings together with no join character,
626 or by a comma and a second separator character, in which case the text
627 strings within a TXT record are joined on that second character.
628 Administrators are reminded that DNS provides no ordering guarantees
629 between multiple records in an RRset. For example:
631 foo.example. IN TXT "a" "b" "c"
632 foo.example. IN TXT "d" "e" "f"
634 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
635 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
636 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
642 1. Native DKIM support without an external library.
643 (Note that if no action to prevent it is taken, a straight upgrade will
644 result in DKIM verification of all signed incoming emails. See spec
645 for details on conditionally disabling)
647 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
649 3. There is now a bool{} expansion condition which maps certain strings to
650 true/false condition values (most likely of use in conjunction with the
651 and{} expansion operator).
653 4. The $spam_score, $spam_bar and $spam_report variables are now available
656 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
657 options, provided that Exim is invoked by an admin_user.
659 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
660 which increases compatibility with older clients at the cost of decreased
661 security. Don't set this unless you need to support such clients.
663 7. There is a new expansion operator, ${randint:...} which will produce a
664 "random" number less than the supplied integer. This randomness is
665 not guaranteed to be cryptographically strong, but depending upon how
666 Exim was built may be better than the most naive schemes.
668 8. Exim now explicitly ensures that SHA256 is available when linked against
671 9. The transport_filter_timeout option now applies to SMTP transports too.
677 1. Preliminary DKIM support in Experimental.
683 1. The body_linecount and body_zerocount C variables are now exported in the
686 2. When a dnslists lookup succeeds, the key that was looked up is now placed
687 in $dnslist_matched. When the key is an IP address, it is not reversed in
688 this variable (though it is, of course, in the actual lookup). In simple
691 deny dnslists = spamhaus.example
693 the key is also available in another variable (in this case,
694 $sender_host_address). In more complicated cases, however, this is not
695 true. For example, using a data lookup might generate a dnslists lookup
698 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
700 If this condition succeeds, the value in $dnslist_matched might be
701 192.168.6.7 (for example).
703 3. Authenticators now have a client_condition option. When Exim is running as
704 a client, it skips an authenticator whose client_condition expansion yields
705 "0", "no", or "false". This can be used, for example, to skip plain text
706 authenticators when the connection is not encrypted by a setting such as:
708 client_condition = ${if !eq{$tls_cipher}{}}
710 Note that the 4.67 documentation states that $tls_cipher contains the
711 cipher used for incoming messages. In fact, during SMTP delivery, it
712 contains the cipher used for the delivery. The same is true for
715 4. There is now a -Mvc <message-id> option, which outputs a copy of the
716 message to the standard output, in RFC 2822 format. The option can be used
717 only by an admin user.
719 5. There is now a /noupdate option for the ratelimit ACL condition. It
720 computes the rate and checks the limit as normal, but it does not update
721 the saved data. This means that, in relevant ACLs, it is possible to lookup
722 the existence of a specified (or auto-generated) ratelimit key without
723 incrementing the ratelimit counter for that key.
725 In order for this to be useful, another ACL entry must set the rate
726 for the same key somewhere (otherwise it will always be zero).
731 # Read the rate; if it doesn't exist or is below the maximum
733 deny ratelimit = 100 / 5m / strict / noupdate
734 log_message = RATE: $sender_rate / $sender_rate_period \
735 (max $sender_rate_limit)
737 [... some other logic and tests...]
739 warn ratelimit = 100 / 5m / strict / per_cmd
740 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
741 (max $sender_rate_limit)
742 condition = ${if le{$sender_rate}{$sender_rate_limit}}
746 6. The variable $max_received_linelength contains the number of bytes in the
747 longest line that was received as part of the message, not counting the
748 line termination character(s).
750 7. Host lists can now include +ignore_defer and +include_defer, analagous to
751 +ignore_unknown and +include_unknown. These options should be used with
752 care, probably only in non-critical host lists such as whitelists.
754 8. There's a new option called queue_only_load_latch, which defaults true.
755 If set false when queue_only_load is greater than zero, Exim re-evaluates
756 the load for each incoming message in an SMTP session. Otherwise, once one
757 message is queued, the remainder are also.
759 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
760 cases when an SMTP session ends without sending QUIT. However, when Exim
761 itself is is bad trouble, such as being unable to write to its log files,
762 this ACL is not run, because it might try to do things (such as write to
763 log files) that make the situation even worse.
765 Like the QUIT ACL, this new ACL is provided to make it possible to gather
766 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
767 modifier is forbidden in this ACL.
769 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
770 to a string that indicates the reason for the termination of the SMTP
771 connection. The possible values are:
773 acl-drop Another ACL issued a "drop" command
774 bad-commands Too many unknown or non-mail commands
775 command-timeout Timeout while reading SMTP commands
776 connection-lost The SMTP connection has been lost
777 data-timeout Timeout while reading message data
778 local-scan-error The local_scan() function crashed
779 local-scan-timeout The local_scan() function timed out
780 signal-exit SIGTERM or SIGINT
781 synchronization-error SMTP synchronization error
782 tls-failed TLS failed to start
784 In most cases when an SMTP connection is closed without having received
785 QUIT, Exim sends an SMTP response message before actually closing the
786 connection. With the exception of acl-drop, the default message can be
787 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
788 "drop" verb in another ACL, it is the message from the other ACL that is
791 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
792 servers with individual queries. This is done by starting the query with
793 "servers=x:y:z;", where each item in the list may take one of two forms:
795 (1) If it is just a host name, the appropriate global option (mysql_servers
796 or pgsql_servers) is searched for a host of the same name, and the
797 remaining parameters (database, user, password) are taken from there.
799 (2) If it contains any slashes, it is taken as a complete parameter set.
801 The list of servers is used in exactly the same was as the global list.
802 Once a connection to a server has happened and a query has been
803 successfully executed, processing of the lookup ceases.
805 This feature is intended for use in master/slave situations where updates
806 are occurring, and one wants to update a master rather than a slave. If the
807 masters are in the list for reading, you might have:
809 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
811 In an updating lookup, you could then write
813 ${lookup mysql{servers=master; UPDATE ...}
815 If, on the other hand, the master is not to be used for reading lookups:
817 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
819 you can still update the master by
821 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
823 11. The message_body_newlines option (default FALSE, for backwards
824 compatibility) can be used to control whether newlines are present in
825 $message_body and $message_body_end. If it is FALSE, they are replaced by
832 1. There is a new log selector called smtp_no_mail, which is not included in
833 the default setting. When it is set, a line is written to the main log
834 whenever an accepted SMTP connection terminates without having issued a
837 2. When an item in a dnslists list is followed by = and & and a list of IP
838 addresses, the behaviour was not clear when the lookup returned more than
839 one IP address. This has been solved by the addition of == and =& for "all"
840 rather than the default "any" matching.
842 3. Up till now, the only control over which cipher suites GnuTLS uses has been
843 for the cipher algorithms. New options have been added to allow some of the
844 other parameters to be varied.
846 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
847 set, Exim compiles a runtime option called disable_fsync.
849 5. There is a new variable called $smtp_count_at_connection_start.
851 6. There's a new control called no_pipelining.
853 7. There are two new variables called $sending_ip_address and $sending_port.
854 These are set whenever an SMTP connection to another host has been set up.
856 8. The expansion of the helo_data option in the smtp transport now happens
857 after the connection to the server has been made.
859 9. There is a new expansion operator ${rfc2047d: that decodes strings that
860 are encoded as per RFC 2047.
862 10. There is a new log selector called "pid", which causes the current process
863 id to be added to every log line, in square brackets, immediately after the
866 11. Exim has been modified so that it flushes SMTP output before implementing
867 a delay in an ACL. It also flushes the output before performing a callout,
868 as this can take a substantial time. These behaviours can be disabled by
869 obeying control = no_delay_flush or control = no_callout_flush,
870 respectively, at some earlier stage of the connection.
872 12. There are two new expansion conditions that iterate over a list. They are
873 called forany and forall.
875 13. There's a new global option called dsn_from that can be used to vary the
876 contents of From: lines in bounces and other automatically generated
877 messages ("delivery status notifications" - hence the name of the option).
879 14. The smtp transport has a new option called hosts_avoid_pipelining.
881 15. By default, exigrep does case-insensitive matches. There is now a -I option
882 that makes it case-sensitive.
884 16. A number of new features ("addresses", "map", "filter", and "reduce") have
885 been added to string expansions to make it easier to process lists of
886 items, typically addresses.
888 17. There's a new ACL modifier called "continue". It does nothing of itself,
889 and processing of the ACL always continues with the next condition or
890 modifier. It is provided so that the side effects of expanding its argument
893 18. It is now possible to use newline and other control characters (those with
894 values less than 32, plus DEL) as separators in lists.
896 19. The exigrep utility now has a -v option, which inverts the matching
899 20. The host_find_failed option in the manualroute router can now be set to
906 No new features were added to 4.66.
912 No new features were added to 4.65.
918 1. ACL variables can now be given arbitrary names, as long as they start with
919 "acl_c" or "acl_m" (for connection variables and message variables), are at
920 least six characters long, with the sixth character being either a digit or
923 2. There is a new ACL modifier called log_reject_target. It makes it possible
924 to specify which logs are used for messages about ACL rejections.
926 3. There is a new authenticator called "dovecot". This is an interface to the
927 authentication facility of the Dovecot POP/IMAP server, which can support a
928 number of authentication methods.
930 4. The variable $message_headers_raw provides a concatenation of all the
931 messages's headers without any decoding. This is in contrast to
932 $message_headers, which does RFC2047 decoding on the header contents.
934 5. In a DNS black list, if two domain names, comma-separated, are given, the
935 second is used first to do an initial check, making use of any IP value
936 restrictions that are set. If there is a match, the first domain is used,
937 without any IP value restrictions, to get the TXT record.
939 6. All authenticators now have a server_condition option.
941 7. There is a new command-line option called -Mset. It is useful only in
942 conjunction with -be (that is, when testing string expansions). It must be
943 followed by a message id; Exim loads the given message from its spool
944 before doing the expansions.
946 8. Another similar new command-line option is called -bem. It operates like
947 -be except that it must be followed by the name of a file that contains a
950 9. When an address is delayed because of a 4xx response to a RCPT command, it
951 is now the combination of sender and recipient that is delayed in
952 subsequent queue runs until its retry time is reached.
954 10. Unary negation and the bitwise logical operators and, or, xor, not, and
955 shift, have been added to the eval: and eval10: expansion items.
957 11. The variables $interface_address and $interface_port have been renamed
958 as $received_ip_address and $received_port, to make it clear that they
959 relate to message reception rather than delivery. (The old names remain
960 available for compatibility.)
962 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
963 to vary the message that is sent when an SMTP command is accepted.
969 1. There is a new Boolean option called filter_prepend_home for the redirect
972 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
973 start of receiving a non-SMTP message, before any of the message has been
976 3. When an SMTP error message is specified in a "message" modifier in an ACL,
977 or in a :fail: or :defer: message in a redirect router, Exim now checks the
978 start of the message for an SMTP error code.
980 4. There is a new parameter for LDAP lookups called "referrals", which takes
981 one of the settings "follow" (the default) or "nofollow".
983 5. Version 20070721.2 of exipick now included, offering these new options:
985 After all other sorting options have bee processed, reverse order
986 before displaying messages (-R is synonym).
988 Randomize order of matching messages before displaying.
990 Instead of displaying the matching messages, display the sum
992 --sort <variable>[,<variable>...]
993 Before displaying matching messages, sort the messages according to
994 each messages value for each variable.
996 Negate the value for every test (returns inverse output from the
997 same criteria without --not).
1003 1. The ${readsocket expansion item now supports Internet domain sockets as well
1004 as Unix domain sockets. If the first argument begins "inet:", it must be of
1005 the form "inet:host:port". The port is mandatory; it may be a number or the
1006 name of a TCP port in /etc/services. The host may be a name, or it may be an
1007 IP address. An ip address may optionally be enclosed in square brackets.
1008 This is best for IPv6 addresses. For example:
1010 ${readsocket{inet:[::1]:1234}{<request data>}...
1012 Only a single host name may be given, but if looking it up yield more than
1013 one IP address, they are each tried in turn until a connection is made. Once
1014 a connection has been made, the behaviour is as for ${readsocket with a Unix
1017 2. If a redirect router sets up file or pipe deliveries for more than one
1018 incoming address, and the relevant transport has batch_max set greater than
1019 one, a batch delivery now occurs.
1021 3. The appendfile transport has a new option called maildirfolder_create_regex.
1022 Its value is a regular expression. For a maildir delivery, this is matched
1023 against the maildir directory; if it matches, Exim ensures that a
1024 maildirfolder file is created alongside the new, cur, and tmp directories.
1030 The documentation is up-to-date for the 4.61 release. Major new features since
1031 the 4.60 release are:
1033 . An option called disable_ipv6, to disable the use of IPv6 completely.
1035 . An increase in the number of ACL variables to 20 of each type.
1037 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
1038 $2, $3, (though those are still set) because the numeric variables get used
1039 for other things in complicated expansions.
1041 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1043 . It is possible to use setclassresources() on some BSD OS to control the
1044 resources used in pipe deliveries.
1046 . A new ACL modifier called add_header, which can be used with any verb.
1048 . More errors are detectable in retry rules.
1050 There are a number of other additions too.
1056 The documentation is up-to-date for the 4.60 release. Major new features since
1057 the 4.50 release are:
1059 . Support for SQLite.
1061 . Support for IGNOREQUOTA in LMTP.
1063 . Extensions to the "submission mode" features.
1065 . Support for Client SMTP Authorization (CSA).
1067 . Support for ratelimiting hosts and users.
1069 . New expansion items to help with the BATV "prvs" scheme.
1071 . A "match_ip" condition, that matches an IP address against a list.
1073 There are many more minor changes.
git://git.exim.org / exim.git / blob