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. The CHUNKING ESMTP extension from RFC 3030. May give some slight
30 performance increase and network load decrease. Main config option
31 chucking_advertise_hosts for control.
37 1. The ACL conditions regex and mime_regex now capture substrings
38 into numeric variables $regex1 to 9, like the "match" expansion condition.
40 2. New $callout_address variable records the address used for a spam=,
41 malware= or verify= callout.
43 3. Transports now take a "max_parallel" option, to limit concurrency.
45 4. Expansion operators ${ipv6norm:<string>} and ${ipv6denorm:<string>}.
46 The latter expands to a 8-element colon-sep set of hex digits including
47 leading zeroes. A trailing ipv4-style dotted-decimal set is converted
48 to hex. Pure ipv4 addresses are converted to IPv4-mapped IPv6.
49 The former operator strips leading zeroes and collapses the longest
50 set of 0-groups to a double-colon.
52 5. New "-bP config" support, to dump the effective configuration.
54 6. New $dkim_key_length variable.
56 7. New base64d and base64 expansion items (the existing str2b64 being a
57 synonym of the latter). Add support in base64 for certificates.
59 8. New main configuration option "bounce_return_linesize_limit" to
60 avoid oversize bodies in bounces. The dafault value matches RFC
63 9. New $initial_cwd expansion variable.
69 1. Support for using the system standard CA bundle.
71 2. New expansion items $config_file, $config_dir, containing the file
72 and directory name of the main configuration file. Also $exim_version.
74 3. New "malware=" support for Avast.
76 4. New "spam=" variant option for Rspamd.
78 5. Assorted options on malware= and spam= scanners.
80 6. A commandline option to write a comment into the logfile.
82 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
83 be configured to make connections via socks5 proxies.
85 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
86 the transmission of UTF-8 envelope addresses.
88 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
89 used encoding of Maildir folder names.
91 10. A logging option for slow DNS lookups.
93 11. New ${env {<variable>}} expansion.
95 12. A non-SMTP authenticator using information from TLS client certificates.
97 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
98 Patch originally by Wolfgang Breyha.
100 14. Main option "dns_trust_aa" for trusting your local nameserver at the
101 same level as DNSSEC.
107 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
108 DANE smtp draft to assess a secure chain of trust of the certificate
109 used to establish the TLS connection based on a TLSA record in the
110 domain of the sender.
112 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
113 and several new events have been created. The reason is because it has
114 been expanded beyond just firing events during the transport phase. Any
115 existing TPDA transport options will have to be rewritten to use a new
116 $event_name expansion variable in a condition. Refer to the
117 experimental-spec.txt for details and examples.
119 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
120 server certs used for TLS match the result of the MX lookup. It does
121 not use the same mechanism as DANE.
131 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
132 configured to expect an initial header from a proxy that will make the
133 actual external source IP:host be used in exim instead of the IP of the
134 proxy that is connecting to it.
136 2. New verify option header_names_ascii, which will check to make sure
137 there are no non-ASCII characters in header names. Exim itself handles
138 those non-ASCII characters, but downstream apps may not, so Exim can
139 detect and reject if those characters are present.
141 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
142 codepoints with valid ones.
144 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
145 command line and matching a regex against the return data for trigger
146 and a second regex to extract malware_name. The mail spoolfile name can
147 be included in the command line.
149 5. The smtp transport now supports options "tls_verify_hosts" and
150 "tls_try_verify_hosts". If either is set the certificate verification
151 is split from the encryption operation. The default remains that a failed
152 verification cancels the encryption.
154 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
155 lookup can now set a list of servers to use that is different from the
158 7. New command-line option -C for exiqgrep to specify alternate exim.conf
159 file when searching the queue.
161 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
163 9. Support for DNSSEC on outbound connections.
165 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
166 "certextract" to extract fields from them. Hash operators md5 and sha1
167 work over them for generating fingerprints, and a new sha256 operator
170 11. PRDR is now supported dy default.
172 12. OCSP stapling is now supported by default.
174 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
175 Delivery Status Notification messages in MIME format, and negociate
176 DSN features per RFC 3461.
182 1. New command-line option -bI:sieve will list all supported sieve extensions
183 of this Exim build on standard output, one per line.
184 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
185 query this to establish the correct list to include in the protocol's
186 SIEVE capability line.
188 2. If the -n option is combined with the -bP option, then the name of an
189 emitted option is not output, only the value (if visible to you).
190 For instance, "exim -n -bP pid_file_path" should just emit a pathname
191 followed by a newline, and no other text.
193 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
194 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
195 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
196 acceptable for security. (Option accepted but ignored if using OpenSSL).
197 Defaults to 1024, the old value. May be lowered only to 512, or raised as
198 far as you like. Raising this may hinder TLS interoperability with other
199 sites and is not currently recommended. Lowering this will permit you to
200 establish a TLS session which is not as secure as you might like.
202 Unless you really know what you are doing, leave it alone.
204 4. If not built with DISABLE_DNSSEC, Exim now has the main option
205 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
206 to send the DO flag to your recursive resolver. If you have a recursive
207 resolver, which can set the Authenticated Data (AD) flag in results, Exim
208 can now detect this. Exim does not perform validation itself, instead
209 relying upon a trusted path to the resolver.
211 Current status: work-in-progress; $sender_host_dnssec variable added.
213 5. DSCP support for outbound connections: on a transport using the smtp driver,
214 set "dscp = ef", for instance, to cause the connections to have the relevant
215 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
217 Similarly for inbound connections, there is a new control modifier, dscp,
218 so "warn control = dscp/ef" in the connect ACL, or after authentication.
220 Supported values depend upon system libraries. "exim -bI:dscp" to list the
221 ones Exim knows of. You can also set a raw number 0..0x3F.
223 6. The -G command-line flag is no longer ignored; it is now equivalent to an
224 ACL setting "control = suppress_local_fixups". The -L command-line flag
225 is now accepted and forces use of syslog, with the provided tag as the
226 process name. A few other flags used by Sendmail are now accepted and
229 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
230 ACL modifier; works for single-recipient mails which are recieved on and
231 deliverable via SMTP. Using the connection made for a recipient verify,
232 if requested before the verify, or a new one made for the purpose while
233 the inbound connection is still active. The bulk of the mail item is copied
234 direct from the inbound socket to the outbound (as well as the spool file).
235 When the source notifies the end of data, the data acceptance by the destination
236 is negociated before the acceptance is sent to the source. If the destination
237 does not accept the mail item, for example due to content-scanning, the item
238 is not accepted from the source and therefore there is no need to generate
239 a bounce mail. This is of benefit when providing a secondary-MX service.
240 The downside is that delays are under the control of the ultimate destination
243 The Recieved-by: header on items delivered by cutthrough is generated
244 early in reception rather than at the end; this will affect any timestamp
245 included. The log line showing delivery is recorded before that showing
246 reception; it uses a new ">>" tag instead of "=>".
248 To support the feature, verify-callout connections can now use ESMTP and TLS.
249 The usual smtp transport options are honoured, plus a (new, default everything)
250 hosts_verify_avoid_tls.
252 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
253 for specific access to the information for each connection. The old names
254 are present for now but deprecated.
256 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
258 8. New expansion operators ${listnamed:name} to get the content of a named list
259 and ${listcount:string} to count the items in a list.
261 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
262 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
263 modules. For some situations this is desirable, but we expect admin in
264 those situations to know they want the feature. More commonly, it means
265 that GUI user modules get loaded and are broken by the setuid Exim being
266 unable to access files specified in environment variables and passed
267 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
268 unless this new option is set.
270 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
271 so have also added a build option which can be used to build Exim with GnuTLS
272 but without trying to use any kind of PKCS11 support. Uncomment this in the
275 AVOID_GNUTLS_PKCS11=yes
277 10. The "acl = name" condition on an ACL now supports optional arguments.
278 New expansion item "${acl {name}{arg}...}" and expansion condition
279 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
280 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
281 Variable $acl_narg contains the number of arguments. If the ACL sets
282 a "message =" value this becomes the result of the expansion item,
283 or the value of $value for the expansion condition. If the ACL returns
284 accept the expansion condition is true; if reject, false. A defer
285 return results in a forced fail.
287 11. Routers and transports can now have multiple headers_add and headers_remove
288 option lines. The concatenated list is used.
290 12. New ACL modifier "remove_header" can remove headers before message gets
291 handled by routers/transports.
293 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
294 "aaaa" and "a" lookups is done and the full set of results returned.
296 14. New expansion variable $headers_added with content from ACL add_header
297 modifier (but not yet added to message).
299 15. New 8bitmime status logging option for received messages. Log field "M8S".
301 16. New authenticated_sender logging option, adding to log field "A".
303 17. New expansion variables $router_name and $transport_name. Useful
304 particularly for debug_print as -bt commandline option does not
305 require privilege whereas -d does.
307 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
308 proposed extension to SMTP from Eric Hall.
310 19. The pipe transport has gained the force_command option, to allow
311 decorating commands from user .forward pipe aliases with prefix
312 wrappers, for instance.
314 20. Callout connections can now AUTH; the same controls as normal delivery
317 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
318 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
319 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
320 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
321 dmarc_status. It adds new control flags dmarc_disable_verify and
322 dmarc_enable_forensic.
324 22. Add expansion variable $authenticated_fail_id, which is the username
325 provided to the authentication method which failed. It is available
326 for use in subsequent ACL processing (typically quit or notquit ACLs).
328 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
331 24. New ${hexquote:..string..} expansion operator converts non-printable
332 characters in the string to \xNN form.
334 25. Experimental TPDA (Transport Post Delivery Action) function added.
335 Patch provided by Axel Rau.
337 26. Experimental Redis lookup added. Patch provided by Warren Baker.
343 1. New authenticator driver, "gsasl". Server-only (at present).
344 This is a SASL interface, licensed under GPL, which can be found at
345 http://www.gnu.org/software/gsasl/.
346 This system does not provide sources of data for authentication, so
347 careful use needs to be made of the conditions in Exim.
349 2. New authenticator driver, "heimdal_gssapi". Server-only.
350 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
351 is no longer honoured for setuid programs by Heimdal. Use the
352 "server_keytab" option to point to the keytab.
354 3. The "pkg-config" system can now be used when building Exim to reference
355 cflags and library information for lookups and authenticators, rather
356 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
357 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
358 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
360 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
361 find the headers and libraries for PCRE.
363 4. New expansion variable $tls_bits.
365 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
366 be joined together with ASCII NUL characters to construct the key to pass
367 into the DBM library. Can be used with gsasl to access sasldb2 files as
370 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
372 Avoid release 1.0.1a if you can. Note that the default value of
373 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
374 increased susceptibility to attack. This may still have interoperability
375 implications for very old clients (see version 4.31 change 37) but
376 administrators can choose to make the trade-off themselves and restore
377 compatibility at the cost of session security.
379 7. Use of the new expansion variable $tls_sni in the main configuration option
380 tls_certificate will cause Exim to re-expand the option, if the client
381 sends the TLS Server Name Indication extension, to permit choosing a
382 different certificate; tls_privatekey will also be re-expanded. You must
383 still set these options to expand to valid files when $tls_sni is not set.
385 The SMTP Transport has gained the option tls_sni, which will set a hostname
386 for outbound TLS sessions, and set $tls_sni too.
388 A new log_selector, +tls_sni, has been added, to log received SNI values
389 for Exim as a server.
391 8. The existing "accept_8bitmime" option now defaults to true. This means
392 that Exim is deliberately not strictly RFC compliant. We're following
393 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
394 Those who disagree, or know that they are talking to mail servers that,
395 even today, are not 8-bit clean, need to turn off this option.
397 9. Exim can now be started with -bw (with an optional timeout, given as
398 -bw<timespec>). With this, stdin at startup is a socket that is
399 already listening for connections. This has a more modern name of
400 "socket activation", but forcing the activated socket to fd 0. We're
401 interested in adding more support for modern variants.
403 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
404 for numbers indicates multiplication by 1024^3.
406 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
407 gnutls_require_mac & gnutls_require_protocols are no longer supported.
408 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
409 string, documentation for which is at:
410 http://www.gnutls.org/manual/html_node/Priority-Strings.html
412 SNI support has been added to Exim's GnuTLS integration too.
414 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
415 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
417 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
418 is now available. If the contents of the file are valid, then Exim will
419 send that back in response to a TLS status request; this is OCSP Stapling.
420 Exim will not maintain the contents of the file in any way: administrators
421 are responsible for ensuring that it is up-to-date.
423 See "experimental-spec.txt" for more details.
425 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
426 identically to TXT record lookups.
428 14. New expansion variable $tod_epoch_l for higher-precision time.
430 15. New global option tls_dh_max_bits, defaulting to current value of NSS
431 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
432 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
434 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
435 Option can now be a path or an identifier for a standard prime.
436 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
437 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
440 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
441 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
442 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
448 1. New options for the ratelimit ACL condition: /count= and /unique=.
449 The /noupdate option has been replaced by a /readonly option.
451 2. The SMTP transport's protocol option may now be set to "smtps", to
452 use SSL-on-connect outbound.
454 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
455 there is a problem talking to the AV scanner, or the AV scanner running.
457 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
458 and check if the search item is a member of the list. This does not
459 support named lists, but does subject the list part to string expansion.
461 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
462 built, Exim no longer performs string expansion on the second string of
463 the match_* expansion conditions: "match_address", "match_domain",
464 "match_ip" & "match_local_part". Named lists can still be used.
470 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
471 or off in the resolver library.
477 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
478 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
479 libraries. The following global options have been added in support of
480 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
481 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
483 2. The pipe transport now takes a boolean option, "freeze_signal", default
484 false. When true, if the external delivery command exits on a signal then
485 Exim will freeze the message in the queue, instead of generating a bounce.
487 3. Log filenames may now use %M as an escape, instead of %D (still available).
488 The %M pattern expands to yyyymm, providing month-level resolution.
490 4. The $message_linecount variable is now updated for the maildir_tag option,
491 in the same way as $message_size, to reflect the real number of lines,
492 including any header additions or removals from transport.
494 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
495 Exim now selects entries randomly, to better scale in a cluster setup.
501 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
502 the flaw permitted the Exim run-time user to cause root to append to
503 arbitrary files of the attacker's choosing, with the content based
504 on content supplied by the attacker.
506 2. Exim now supports loading some lookup types at run-time, using your
507 platform's dlopen() functionality. This has limited platform support
508 and the intention is not to support every variant, it's limited to
509 dlopen(). This permits the main Exim binary to not be linked against
510 all the libraries needed for all the lookup types.
516 NOTE: this version is not guaranteed backwards-compatible, please read the
517 items below carefully
519 1. A new main configuration option, "openssl_options", is available if Exim
520 is built with SSL support provided by OpenSSL. The option allows
521 administrators to specify OpenSSL options to be used on connections;
522 typically this is to set bug compatibility features which the OpenSSL
523 developers have not enabled by default. There may be security
524 consequences for certain options, so these should not be changed
527 2. A new pipe transport option, "permit_coredumps", may help with problem
528 diagnosis in some scenarios. Note that Exim is typically installed as
529 a setuid binary, which on most OSes will inhibit coredumps by default,
530 so that safety mechanism would have to be overridden for this option to
531 be able to take effect.
533 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
534 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
535 Note that this switches Exim to use a new API ("INSTREAM") and a future
536 release of ClamAV will remove support for the old API ("STREAM").
538 The av_scanner option, when set to "clamd", now takes an optional third
539 part, "local", which causes Exim to pass a filename to ClamAV instead of
540 the file content. This is the same behaviour as when clamd is pointed at
541 a Unix-domain socket. For example:
543 av_scanner = clamd:192.0.2.3 1234:local
545 ClamAV's ExtendedDetectionInfo response format is now handled.
547 4. There is now a -bmalware option, restricted to admin users. This option
548 takes one parameter, a filename, and scans that file with Exim's
549 malware-scanning framework. This is intended purely as a debugging aid
550 to ensure that Exim's scanning is working, not to replace other tools.
551 Note that the ACL framework is not invoked, so if av_scanner references
552 ACL variables without a fallback then this will fail.
554 5. There is a new expansion operator, "reverse_ip", which will reverse IP
555 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
557 ${reverse_ip:192.0.2.4}
559 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
560 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
562 6. There is a new ACL control called "debug", to enable debug logging.
563 This allows selective logging of certain incoming transactions within
564 production environments, with some care. It takes two options, "tag"
565 and "opts"; "tag" is included in the filename of the log and "opts"
566 is used as per the -d<options> command-line option. Examples, which
567 don't all make sense in all contexts:
570 control = debug/tag=.$sender_host_address
571 control = debug/opts=+expand+acl
572 control = debug/tag=.$message_exim_id/opts=+expand
574 7. It has always been implicit in the design and the documentation that
575 "the Exim user" is not root. src/EDITME said that using root was
576 "very strongly discouraged". This is not enough to keep people from
577 shooting themselves in the foot in days when many don't configure Exim
578 themselves but via package build managers. The security consequences of
579 running various bits of network code are severe if there should be bugs in
580 them. As such, the Exim user may no longer be root. If configured
581 statically, Exim will refuse to build. If configured as ref:user then Exim
582 will exit shortly after start-up. If you must shoot yourself in the foot,
583 then henceforth you will have to maintain your own local patches to strip
586 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
587 condition logic to determine truth/failure and will fail to expand many
588 strings, bool_lax{} uses the router condition logic, where most strings
590 Note: bool{00} is false, bool_lax{00} is true.
592 9. Routers now support multiple "condition" tests.
594 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
595 Setting this allows an admin to define which entry in the tcpwrappers
596 config file will be used to control access to the daemon. This option
597 is only available when Exim is built with USE_TCP_WRAPPERS. The
598 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
601 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
602 the Exim run-time user, instead of root.
604 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
605 is forced on. This is mitigated by the new build option
606 TRUSTED_CONFIG_LIST which defines a list of configuration files which
607 are trusted; one per line. If a config file is owned by root and matches
608 a pathname in the list, then it may be invoked by the Exim build-time
609 user without Exim relinquishing root privileges.
611 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
612 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
613 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
614 include the main config. As a transition mechanism, we are temporarily
615 providing a work-around: the new build option WHITELIST_D_MACROS provides
616 a colon-separated list of macro names which may be overridden by the Exim
617 run-time user. The values of these macros are constrained to the regex
618 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
624 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
625 writable, the other to locking of MBX folders (not mbox).
627 2. MySQL stored procedures are now supported.
629 3. The dkim_domain transport option is now a list, not a single string, and
630 messages will be signed for each element in the list (discarding
633 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
634 in the presence of multiple character strings within the RR. Prior to 4.70,
635 only the first string would be returned. The dnsdb lookup now, by default,
636 preserves the pre-4.70 semantics, but also now takes an extended output
637 separator specification. The separator can be followed by a semicolon, to
638 concatenate the individual text strings together with no join character,
639 or by a comma and a second separator character, in which case the text
640 strings within a TXT record are joined on that second character.
641 Administrators are reminded that DNS provides no ordering guarantees
642 between multiple records in an RRset. For example:
644 foo.example. IN TXT "a" "b" "c"
645 foo.example. IN TXT "d" "e" "f"
647 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
648 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
649 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
655 1. Native DKIM support without an external library.
656 (Note that if no action to prevent it is taken, a straight upgrade will
657 result in DKIM verification of all signed incoming emails. See spec
658 for details on conditionally disabling)
660 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
662 3. There is now a bool{} expansion condition which maps certain strings to
663 true/false condition values (most likely of use in conjunction with the
664 and{} expansion operator).
666 4. The $spam_score, $spam_bar and $spam_report variables are now available
669 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
670 options, provided that Exim is invoked by an admin_user.
672 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
673 which increases compatibility with older clients at the cost of decreased
674 security. Don't set this unless you need to support such clients.
676 7. There is a new expansion operator, ${randint:...} which will produce a
677 "random" number less than the supplied integer. This randomness is
678 not guaranteed to be cryptographically strong, but depending upon how
679 Exim was built may be better than the most naive schemes.
681 8. Exim now explicitly ensures that SHA256 is available when linked against
684 9. The transport_filter_timeout option now applies to SMTP transports too.
690 1. Preliminary DKIM support in Experimental.
696 1. The body_linecount and body_zerocount C variables are now exported in the
699 2. When a dnslists lookup succeeds, the key that was looked up is now placed
700 in $dnslist_matched. When the key is an IP address, it is not reversed in
701 this variable (though it is, of course, in the actual lookup). In simple
704 deny dnslists = spamhaus.example
706 the key is also available in another variable (in this case,
707 $sender_host_address). In more complicated cases, however, this is not
708 true. For example, using a data lookup might generate a dnslists lookup
711 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
713 If this condition succeeds, the value in $dnslist_matched might be
714 192.168.6.7 (for example).
716 3. Authenticators now have a client_condition option. When Exim is running as
717 a client, it skips an authenticator whose client_condition expansion yields
718 "0", "no", or "false". This can be used, for example, to skip plain text
719 authenticators when the connection is not encrypted by a setting such as:
721 client_condition = ${if !eq{$tls_cipher}{}}
723 Note that the 4.67 documentation states that $tls_cipher contains the
724 cipher used for incoming messages. In fact, during SMTP delivery, it
725 contains the cipher used for the delivery. The same is true for
728 4. There is now a -Mvc <message-id> option, which outputs a copy of the
729 message to the standard output, in RFC 2822 format. The option can be used
730 only by an admin user.
732 5. There is now a /noupdate option for the ratelimit ACL condition. It
733 computes the rate and checks the limit as normal, but it does not update
734 the saved data. This means that, in relevant ACLs, it is possible to lookup
735 the existence of a specified (or auto-generated) ratelimit key without
736 incrementing the ratelimit counter for that key.
738 In order for this to be useful, another ACL entry must set the rate
739 for the same key somewhere (otherwise it will always be zero).
744 # Read the rate; if it doesn't exist or is below the maximum
746 deny ratelimit = 100 / 5m / strict / noupdate
747 log_message = RATE: $sender_rate / $sender_rate_period \
748 (max $sender_rate_limit)
750 [... some other logic and tests...]
752 warn ratelimit = 100 / 5m / strict / per_cmd
753 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
754 (max $sender_rate_limit)
755 condition = ${if le{$sender_rate}{$sender_rate_limit}}
759 6. The variable $max_received_linelength contains the number of bytes in the
760 longest line that was received as part of the message, not counting the
761 line termination character(s).
763 7. Host lists can now include +ignore_defer and +include_defer, analagous to
764 +ignore_unknown and +include_unknown. These options should be used with
765 care, probably only in non-critical host lists such as whitelists.
767 8. There's a new option called queue_only_load_latch, which defaults true.
768 If set false when queue_only_load is greater than zero, Exim re-evaluates
769 the load for each incoming message in an SMTP session. Otherwise, once one
770 message is queued, the remainder are also.
772 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
773 cases when an SMTP session ends without sending QUIT. However, when Exim
774 itself is is bad trouble, such as being unable to write to its log files,
775 this ACL is not run, because it might try to do things (such as write to
776 log files) that make the situation even worse.
778 Like the QUIT ACL, this new ACL is provided to make it possible to gather
779 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
780 modifier is forbidden in this ACL.
782 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
783 to a string that indicates the reason for the termination of the SMTP
784 connection. The possible values are:
786 acl-drop Another ACL issued a "drop" command
787 bad-commands Too many unknown or non-mail commands
788 command-timeout Timeout while reading SMTP commands
789 connection-lost The SMTP connection has been lost
790 data-timeout Timeout while reading message data
791 local-scan-error The local_scan() function crashed
792 local-scan-timeout The local_scan() function timed out
793 signal-exit SIGTERM or SIGINT
794 synchronization-error SMTP synchronization error
795 tls-failed TLS failed to start
797 In most cases when an SMTP connection is closed without having received
798 QUIT, Exim sends an SMTP response message before actually closing the
799 connection. With the exception of acl-drop, the default message can be
800 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
801 "drop" verb in another ACL, it is the message from the other ACL that is
804 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
805 servers with individual queries. This is done by starting the query with
806 "servers=x:y:z;", where each item in the list may take one of two forms:
808 (1) If it is just a host name, the appropriate global option (mysql_servers
809 or pgsql_servers) is searched for a host of the same name, and the
810 remaining parameters (database, user, password) are taken from there.
812 (2) If it contains any slashes, it is taken as a complete parameter set.
814 The list of servers is used in exactly the same was as the global list.
815 Once a connection to a server has happened and a query has been
816 successfully executed, processing of the lookup ceases.
818 This feature is intended for use in master/slave situations where updates
819 are occurring, and one wants to update a master rather than a slave. If the
820 masters are in the list for reading, you might have:
822 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
824 In an updating lookup, you could then write
826 ${lookup mysql{servers=master; UPDATE ...}
828 If, on the other hand, the master is not to be used for reading lookups:
830 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
832 you can still update the master by
834 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
836 11. The message_body_newlines option (default FALSE, for backwards
837 compatibility) can be used to control whether newlines are present in
838 $message_body and $message_body_end. If it is FALSE, they are replaced by
845 1. There is a new log selector called smtp_no_mail, which is not included in
846 the default setting. When it is set, a line is written to the main log
847 whenever an accepted SMTP connection terminates without having issued a
850 2. When an item in a dnslists list is followed by = and & and a list of IP
851 addresses, the behaviour was not clear when the lookup returned more than
852 one IP address. This has been solved by the addition of == and =& for "all"
853 rather than the default "any" matching.
855 3. Up till now, the only control over which cipher suites GnuTLS uses has been
856 for the cipher algorithms. New options have been added to allow some of the
857 other parameters to be varied.
859 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
860 set, Exim compiles a runtime option called disable_fsync.
862 5. There is a new variable called $smtp_count_at_connection_start.
864 6. There's a new control called no_pipelining.
866 7. There are two new variables called $sending_ip_address and $sending_port.
867 These are set whenever an SMTP connection to another host has been set up.
869 8. The expansion of the helo_data option in the smtp transport now happens
870 after the connection to the server has been made.
872 9. There is a new expansion operator ${rfc2047d: that decodes strings that
873 are encoded as per RFC 2047.
875 10. There is a new log selector called "pid", which causes the current process
876 id to be added to every log line, in square brackets, immediately after the
879 11. Exim has been modified so that it flushes SMTP output before implementing
880 a delay in an ACL. It also flushes the output before performing a callout,
881 as this can take a substantial time. These behaviours can be disabled by
882 obeying control = no_delay_flush or control = no_callout_flush,
883 respectively, at some earlier stage of the connection.
885 12. There are two new expansion conditions that iterate over a list. They are
886 called forany and forall.
888 13. There's a new global option called dsn_from that can be used to vary the
889 contents of From: lines in bounces and other automatically generated
890 messages ("delivery status notifications" - hence the name of the option).
892 14. The smtp transport has a new option called hosts_avoid_pipelining.
894 15. By default, exigrep does case-insensitive matches. There is now a -I option
895 that makes it case-sensitive.
897 16. A number of new features ("addresses", "map", "filter", and "reduce") have
898 been added to string expansions to make it easier to process lists of
899 items, typically addresses.
901 17. There's a new ACL modifier called "continue". It does nothing of itself,
902 and processing of the ACL always continues with the next condition or
903 modifier. It is provided so that the side effects of expanding its argument
906 18. It is now possible to use newline and other control characters (those with
907 values less than 32, plus DEL) as separators in lists.
909 19. The exigrep utility now has a -v option, which inverts the matching
912 20. The host_find_failed option in the manualroute router can now be set to
919 No new features were added to 4.66.
925 No new features were added to 4.65.
931 1. ACL variables can now be given arbitrary names, as long as they start with
932 "acl_c" or "acl_m" (for connection variables and message variables), are at
933 least six characters long, with the sixth character being either a digit or
936 2. There is a new ACL modifier called log_reject_target. It makes it possible
937 to specify which logs are used for messages about ACL rejections.
939 3. There is a new authenticator called "dovecot". This is an interface to the
940 authentication facility of the Dovecot POP/IMAP server, which can support a
941 number of authentication methods.
943 4. The variable $message_headers_raw provides a concatenation of all the
944 messages's headers without any decoding. This is in contrast to
945 $message_headers, which does RFC2047 decoding on the header contents.
947 5. In a DNS black list, if two domain names, comma-separated, are given, the
948 second is used first to do an initial check, making use of any IP value
949 restrictions that are set. If there is a match, the first domain is used,
950 without any IP value restrictions, to get the TXT record.
952 6. All authenticators now have a server_condition option.
954 7. There is a new command-line option called -Mset. It is useful only in
955 conjunction with -be (that is, when testing string expansions). It must be
956 followed by a message id; Exim loads the given message from its spool
957 before doing the expansions.
959 8. Another similar new command-line option is called -bem. It operates like
960 -be except that it must be followed by the name of a file that contains a
963 9. When an address is delayed because of a 4xx response to a RCPT command, it
964 is now the combination of sender and recipient that is delayed in
965 subsequent queue runs until its retry time is reached.
967 10. Unary negation and the bitwise logical operators and, or, xor, not, and
968 shift, have been added to the eval: and eval10: expansion items.
970 11. The variables $interface_address and $interface_port have been renamed
971 as $received_ip_address and $received_port, to make it clear that they
972 relate to message reception rather than delivery. (The old names remain
973 available for compatibility.)
975 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
976 to vary the message that is sent when an SMTP command is accepted.
982 1. There is a new Boolean option called filter_prepend_home for the redirect
985 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
986 start of receiving a non-SMTP message, before any of the message has been
989 3. When an SMTP error message is specified in a "message" modifier in an ACL,
990 or in a :fail: or :defer: message in a redirect router, Exim now checks the
991 start of the message for an SMTP error code.
993 4. There is a new parameter for LDAP lookups called "referrals", which takes
994 one of the settings "follow" (the default) or "nofollow".
996 5. Version 20070721.2 of exipick now included, offering these new options:
998 After all other sorting options have bee processed, reverse order
999 before displaying messages (-R is synonym).
1001 Randomize order of matching messages before displaying.
1003 Instead of displaying the matching messages, display the sum
1005 --sort <variable>[,<variable>...]
1006 Before displaying matching messages, sort the messages according to
1007 each messages value for each variable.
1009 Negate the value for every test (returns inverse output from the
1010 same criteria without --not).
1016 1. The ${readsocket expansion item now supports Internet domain sockets as well
1017 as Unix domain sockets. If the first argument begins "inet:", it must be of
1018 the form "inet:host:port". The port is mandatory; it may be a number or the
1019 name of a TCP port in /etc/services. The host may be a name, or it may be an
1020 IP address. An ip address may optionally be enclosed in square brackets.
1021 This is best for IPv6 addresses. For example:
1023 ${readsocket{inet:[::1]:1234}{<request data>}...
1025 Only a single host name may be given, but if looking it up yield more than
1026 one IP address, they are each tried in turn until a connection is made. Once
1027 a connection has been made, the behaviour is as for ${readsocket with a Unix
1030 2. If a redirect router sets up file or pipe deliveries for more than one
1031 incoming address, and the relevant transport has batch_max set greater than
1032 one, a batch delivery now occurs.
1034 3. The appendfile transport has a new option called maildirfolder_create_regex.
1035 Its value is a regular expression. For a maildir delivery, this is matched
1036 against the maildir directory; if it matches, Exim ensures that a
1037 maildirfolder file is created alongside the new, cur, and tmp directories.
1043 The documentation is up-to-date for the 4.61 release. Major new features since
1044 the 4.60 release are:
1046 . An option called disable_ipv6, to disable the use of IPv6 completely.
1048 . An increase in the number of ACL variables to 20 of each type.
1050 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
1051 $2, $3, (though those are still set) because the numeric variables get used
1052 for other things in complicated expansions.
1054 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1056 . It is possible to use setclassresources() on some BSD OS to control the
1057 resources used in pipe deliveries.
1059 . A new ACL modifier called add_header, which can be used with any verb.
1061 . More errors are detectable in retry rules.
1063 There are a number of other additions too.
1069 The documentation is up-to-date for the 4.60 release. Major new features since
1070 the 4.50 release are:
1072 . Support for SQLite.
1074 . Support for IGNOREQUOTA in LMTP.
1076 . Extensions to the "submission mode" features.
1078 . Support for Client SMTP Authorization (CSA).
1080 . Support for ratelimiting hosts and users.
1082 . New expansion items to help with the BATV "prvs" scheme.
1084 . A "match_ip" condition, that matches an IP address against a list.
1086 There are many more minor changes.
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