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 chunking_advertise_hosts, and smtp transport option hosts_try_chunking
38 1. The ACL conditions regex and mime_regex now capture substrings
39 into numeric variables $regex1 to 9, like the "match" expansion condition.
41 2. New $callout_address variable records the address used for a spam=,
42 malware= or verify= callout.
44 3. Transports now take a "max_parallel" option, to limit concurrency.
46 4. Expansion operators ${ipv6norm:<string>} and ${ipv6denorm:<string>}.
47 The latter expands to a 8-element colon-sep set of hex digits including
48 leading zeroes. A trailing ipv4-style dotted-decimal set is converted
49 to hex. Pure ipv4 addresses are converted to IPv4-mapped IPv6.
50 The former operator strips leading zeroes and collapses the longest
51 set of 0-groups to a double-colon.
53 5. New "-bP config" support, to dump the effective configuration.
55 6. New $dkim_key_length variable.
57 7. New base64d and base64 expansion items (the existing str2b64 being a
58 synonym of the latter). Add support in base64 for certificates.
60 8. New main configuration option "bounce_return_linesize_limit" to
61 avoid oversize bodies in bounces. The dafault value matches RFC
64 9. New $initial_cwd expansion variable.
70 1. Support for using the system standard CA bundle.
72 2. New expansion items $config_file, $config_dir, containing the file
73 and directory name of the main configuration file. Also $exim_version.
75 3. New "malware=" support for Avast.
77 4. New "spam=" variant option for Rspamd.
79 5. Assorted options on malware= and spam= scanners.
81 6. A commandline option to write a comment into the logfile.
83 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
84 be configured to make connections via socks5 proxies.
86 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
87 the transmission of UTF-8 envelope addresses.
89 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
90 used encoding of Maildir folder names.
92 10. A logging option for slow DNS lookups.
94 11. New ${env {<variable>}} expansion.
96 12. A non-SMTP authenticator using information from TLS client certificates.
98 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
99 Patch originally by Wolfgang Breyha.
101 14. Main option "dns_trust_aa" for trusting your local nameserver at the
102 same level as DNSSEC.
108 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
109 DANE smtp draft to assess a secure chain of trust of the certificate
110 used to establish the TLS connection based on a TLSA record in the
111 domain of the sender.
113 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
114 and several new events have been created. The reason is because it has
115 been expanded beyond just firing events during the transport phase. Any
116 existing TPDA transport options will have to be rewritten to use a new
117 $event_name expansion variable in a condition. Refer to the
118 experimental-spec.txt for details and examples.
120 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
121 server certs used for TLS match the result of the MX lookup. It does
122 not use the same mechanism as DANE.
132 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
133 configured to expect an initial header from a proxy that will make the
134 actual external source IP:host be used in exim instead of the IP of the
135 proxy that is connecting to it.
137 2. New verify option header_names_ascii, which will check to make sure
138 there are no non-ASCII characters in header names. Exim itself handles
139 those non-ASCII characters, but downstream apps may not, so Exim can
140 detect and reject if those characters are present.
142 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
143 codepoints with valid ones.
145 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
146 command line and matching a regex against the return data for trigger
147 and a second regex to extract malware_name. The mail spoolfile name can
148 be included in the command line.
150 5. The smtp transport now supports options "tls_verify_hosts" and
151 "tls_try_verify_hosts". If either is set the certificate verification
152 is split from the encryption operation. The default remains that a failed
153 verification cancels the encryption.
155 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
156 lookup can now set a list of servers to use that is different from the
159 7. New command-line option -C for exiqgrep to specify alternate exim.conf
160 file when searching the queue.
162 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
164 9. Support for DNSSEC on outbound connections.
166 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
167 "certextract" to extract fields from them. Hash operators md5 and sha1
168 work over them for generating fingerprints, and a new sha256 operator
171 11. PRDR is now supported dy default.
173 12. OCSP stapling is now supported by default.
175 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
176 Delivery Status Notification messages in MIME format, and negociate
177 DSN features per RFC 3461.
183 1. New command-line option -bI:sieve will list all supported sieve extensions
184 of this Exim build on standard output, one per line.
185 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
186 query this to establish the correct list to include in the protocol's
187 SIEVE capability line.
189 2. If the -n option is combined with the -bP option, then the name of an
190 emitted option is not output, only the value (if visible to you).
191 For instance, "exim -n -bP pid_file_path" should just emit a pathname
192 followed by a newline, and no other text.
194 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
195 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
196 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
197 acceptable for security. (Option accepted but ignored if using OpenSSL).
198 Defaults to 1024, the old value. May be lowered only to 512, or raised as
199 far as you like. Raising this may hinder TLS interoperability with other
200 sites and is not currently recommended. Lowering this will permit you to
201 establish a TLS session which is not as secure as you might like.
203 Unless you really know what you are doing, leave it alone.
205 4. If not built with DISABLE_DNSSEC, Exim now has the main option
206 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
207 to send the DO flag to your recursive resolver. If you have a recursive
208 resolver, which can set the Authenticated Data (AD) flag in results, Exim
209 can now detect this. Exim does not perform validation itself, instead
210 relying upon a trusted path to the resolver.
212 Current status: work-in-progress; $sender_host_dnssec variable added.
214 5. DSCP support for outbound connections: on a transport using the smtp driver,
215 set "dscp = ef", for instance, to cause the connections to have the relevant
216 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
218 Similarly for inbound connections, there is a new control modifier, dscp,
219 so "warn control = dscp/ef" in the connect ACL, or after authentication.
221 Supported values depend upon system libraries. "exim -bI:dscp" to list the
222 ones Exim knows of. You can also set a raw number 0..0x3F.
224 6. The -G command-line flag is no longer ignored; it is now equivalent to an
225 ACL setting "control = suppress_local_fixups". The -L command-line flag
226 is now accepted and forces use of syslog, with the provided tag as the
227 process name. A few other flags used by Sendmail are now accepted and
230 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
231 ACL modifier; works for single-recipient mails which are recieved on and
232 deliverable via SMTP. Using the connection made for a recipient verify,
233 if requested before the verify, or a new one made for the purpose while
234 the inbound connection is still active. The bulk of the mail item is copied
235 direct from the inbound socket to the outbound (as well as the spool file).
236 When the source notifies the end of data, the data acceptance by the destination
237 is negociated before the acceptance is sent to the source. If the destination
238 does not accept the mail item, for example due to content-scanning, the item
239 is not accepted from the source and therefore there is no need to generate
240 a bounce mail. This is of benefit when providing a secondary-MX service.
241 The downside is that delays are under the control of the ultimate destination
244 The Recieved-by: header on items delivered by cutthrough is generated
245 early in reception rather than at the end; this will affect any timestamp
246 included. The log line showing delivery is recorded before that showing
247 reception; it uses a new ">>" tag instead of "=>".
249 To support the feature, verify-callout connections can now use ESMTP and TLS.
250 The usual smtp transport options are honoured, plus a (new, default everything)
251 hosts_verify_avoid_tls.
253 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
254 for specific access to the information for each connection. The old names
255 are present for now but deprecated.
257 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
259 8. New expansion operators ${listnamed:name} to get the content of a named list
260 and ${listcount:string} to count the items in a list.
262 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
263 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
264 modules. For some situations this is desirable, but we expect admin in
265 those situations to know they want the feature. More commonly, it means
266 that GUI user modules get loaded and are broken by the setuid Exim being
267 unable to access files specified in environment variables and passed
268 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
269 unless this new option is set.
271 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
272 so have also added a build option which can be used to build Exim with GnuTLS
273 but without trying to use any kind of PKCS11 support. Uncomment this in the
276 AVOID_GNUTLS_PKCS11=yes
278 10. The "acl = name" condition on an ACL now supports optional arguments.
279 New expansion item "${acl {name}{arg}...}" and expansion condition
280 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
281 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
282 Variable $acl_narg contains the number of arguments. If the ACL sets
283 a "message =" value this becomes the result of the expansion item,
284 or the value of $value for the expansion condition. If the ACL returns
285 accept the expansion condition is true; if reject, false. A defer
286 return results in a forced fail.
288 11. Routers and transports can now have multiple headers_add and headers_remove
289 option lines. The concatenated list is used.
291 12. New ACL modifier "remove_header" can remove headers before message gets
292 handled by routers/transports.
294 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
295 "aaaa" and "a" lookups is done and the full set of results returned.
297 14. New expansion variable $headers_added with content from ACL add_header
298 modifier (but not yet added to message).
300 15. New 8bitmime status logging option for received messages. Log field "M8S".
302 16. New authenticated_sender logging option, adding to log field "A".
304 17. New expansion variables $router_name and $transport_name. Useful
305 particularly for debug_print as -bt commandline option does not
306 require privilege whereas -d does.
308 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
309 proposed extension to SMTP from Eric Hall.
311 19. The pipe transport has gained the force_command option, to allow
312 decorating commands from user .forward pipe aliases with prefix
313 wrappers, for instance.
315 20. Callout connections can now AUTH; the same controls as normal delivery
318 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
319 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
320 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
321 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
322 dmarc_status. It adds new control flags dmarc_disable_verify and
323 dmarc_enable_forensic.
325 22. Add expansion variable $authenticated_fail_id, which is the username
326 provided to the authentication method which failed. It is available
327 for use in subsequent ACL processing (typically quit or notquit ACLs).
329 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
332 24. New ${hexquote:..string..} expansion operator converts non-printable
333 characters in the string to \xNN form.
335 25. Experimental TPDA (Transport Post Delivery Action) function added.
336 Patch provided by Axel Rau.
338 26. Experimental Redis lookup added. Patch provided by Warren Baker.
344 1. New authenticator driver, "gsasl". Server-only (at present).
345 This is a SASL interface, licensed under GPL, which can be found at
346 http://www.gnu.org/software/gsasl/.
347 This system does not provide sources of data for authentication, so
348 careful use needs to be made of the conditions in Exim.
350 2. New authenticator driver, "heimdal_gssapi". Server-only.
351 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
352 is no longer honoured for setuid programs by Heimdal. Use the
353 "server_keytab" option to point to the keytab.
355 3. The "pkg-config" system can now be used when building Exim to reference
356 cflags and library information for lookups and authenticators, rather
357 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
358 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
359 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
361 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
362 find the headers and libraries for PCRE.
364 4. New expansion variable $tls_bits.
366 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
367 be joined together with ASCII NUL characters to construct the key to pass
368 into the DBM library. Can be used with gsasl to access sasldb2 files as
371 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
373 Avoid release 1.0.1a if you can. Note that the default value of
374 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
375 increased susceptibility to attack. This may still have interoperability
376 implications for very old clients (see version 4.31 change 37) but
377 administrators can choose to make the trade-off themselves and restore
378 compatibility at the cost of session security.
380 7. Use of the new expansion variable $tls_sni in the main configuration option
381 tls_certificate will cause Exim to re-expand the option, if the client
382 sends the TLS Server Name Indication extension, to permit choosing a
383 different certificate; tls_privatekey will also be re-expanded. You must
384 still set these options to expand to valid files when $tls_sni is not set.
386 The SMTP Transport has gained the option tls_sni, which will set a hostname
387 for outbound TLS sessions, and set $tls_sni too.
389 A new log_selector, +tls_sni, has been added, to log received SNI values
390 for Exim as a server.
392 8. The existing "accept_8bitmime" option now defaults to true. This means
393 that Exim is deliberately not strictly RFC compliant. We're following
394 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
395 Those who disagree, or know that they are talking to mail servers that,
396 even today, are not 8-bit clean, need to turn off this option.
398 9. Exim can now be started with -bw (with an optional timeout, given as
399 -bw<timespec>). With this, stdin at startup is a socket that is
400 already listening for connections. This has a more modern name of
401 "socket activation", but forcing the activated socket to fd 0. We're
402 interested in adding more support for modern variants.
404 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
405 for numbers indicates multiplication by 1024^3.
407 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
408 gnutls_require_mac & gnutls_require_protocols are no longer supported.
409 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
410 string, documentation for which is at:
411 http://www.gnutls.org/manual/html_node/Priority-Strings.html
413 SNI support has been added to Exim's GnuTLS integration too.
415 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
416 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
418 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
419 is now available. If the contents of the file are valid, then Exim will
420 send that back in response to a TLS status request; this is OCSP Stapling.
421 Exim will not maintain the contents of the file in any way: administrators
422 are responsible for ensuring that it is up-to-date.
424 See "experimental-spec.txt" for more details.
426 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
427 identically to TXT record lookups.
429 14. New expansion variable $tod_epoch_l for higher-precision time.
431 15. New global option tls_dh_max_bits, defaulting to current value of NSS
432 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
433 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
435 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
436 Option can now be a path or an identifier for a standard prime.
437 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
438 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
441 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
442 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
443 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
449 1. New options for the ratelimit ACL condition: /count= and /unique=.
450 The /noupdate option has been replaced by a /readonly option.
452 2. The SMTP transport's protocol option may now be set to "smtps", to
453 use SSL-on-connect outbound.
455 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
456 there is a problem talking to the AV scanner, or the AV scanner running.
458 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
459 and check if the search item is a member of the list. This does not
460 support named lists, but does subject the list part to string expansion.
462 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
463 built, Exim no longer performs string expansion on the second string of
464 the match_* expansion conditions: "match_address", "match_domain",
465 "match_ip" & "match_local_part". Named lists can still be used.
471 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
472 or off in the resolver library.
478 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
479 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
480 libraries. The following global options have been added in support of
481 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
482 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
484 2. The pipe transport now takes a boolean option, "freeze_signal", default
485 false. When true, if the external delivery command exits on a signal then
486 Exim will freeze the message in the queue, instead of generating a bounce.
488 3. Log filenames may now use %M as an escape, instead of %D (still available).
489 The %M pattern expands to yyyymm, providing month-level resolution.
491 4. The $message_linecount variable is now updated for the maildir_tag option,
492 in the same way as $message_size, to reflect the real number of lines,
493 including any header additions or removals from transport.
495 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
496 Exim now selects entries randomly, to better scale in a cluster setup.
502 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
503 the flaw permitted the Exim run-time user to cause root to append to
504 arbitrary files of the attacker's choosing, with the content based
505 on content supplied by the attacker.
507 2. Exim now supports loading some lookup types at run-time, using your
508 platform's dlopen() functionality. This has limited platform support
509 and the intention is not to support every variant, it's limited to
510 dlopen(). This permits the main Exim binary to not be linked against
511 all the libraries needed for all the lookup types.
517 NOTE: this version is not guaranteed backwards-compatible, please read the
518 items below carefully
520 1. A new main configuration option, "openssl_options", is available if Exim
521 is built with SSL support provided by OpenSSL. The option allows
522 administrators to specify OpenSSL options to be used on connections;
523 typically this is to set bug compatibility features which the OpenSSL
524 developers have not enabled by default. There may be security
525 consequences for certain options, so these should not be changed
528 2. A new pipe transport option, "permit_coredumps", may help with problem
529 diagnosis in some scenarios. Note that Exim is typically installed as
530 a setuid binary, which on most OSes will inhibit coredumps by default,
531 so that safety mechanism would have to be overridden for this option to
532 be able to take effect.
534 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
535 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
536 Note that this switches Exim to use a new API ("INSTREAM") and a future
537 release of ClamAV will remove support for the old API ("STREAM").
539 The av_scanner option, when set to "clamd", now takes an optional third
540 part, "local", which causes Exim to pass a filename to ClamAV instead of
541 the file content. This is the same behaviour as when clamd is pointed at
542 a Unix-domain socket. For example:
544 av_scanner = clamd:192.0.2.3 1234:local
546 ClamAV's ExtendedDetectionInfo response format is now handled.
548 4. There is now a -bmalware option, restricted to admin users. This option
549 takes one parameter, a filename, and scans that file with Exim's
550 malware-scanning framework. This is intended purely as a debugging aid
551 to ensure that Exim's scanning is working, not to replace other tools.
552 Note that the ACL framework is not invoked, so if av_scanner references
553 ACL variables without a fallback then this will fail.
555 5. There is a new expansion operator, "reverse_ip", which will reverse IP
556 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
558 ${reverse_ip:192.0.2.4}
560 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
561 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
563 6. There is a new ACL control called "debug", to enable debug logging.
564 This allows selective logging of certain incoming transactions within
565 production environments, with some care. It takes two options, "tag"
566 and "opts"; "tag" is included in the filename of the log and "opts"
567 is used as per the -d<options> command-line option. Examples, which
568 don't all make sense in all contexts:
571 control = debug/tag=.$sender_host_address
572 control = debug/opts=+expand+acl
573 control = debug/tag=.$message_exim_id/opts=+expand
575 7. It has always been implicit in the design and the documentation that
576 "the Exim user" is not root. src/EDITME said that using root was
577 "very strongly discouraged". This is not enough to keep people from
578 shooting themselves in the foot in days when many don't configure Exim
579 themselves but via package build managers. The security consequences of
580 running various bits of network code are severe if there should be bugs in
581 them. As such, the Exim user may no longer be root. If configured
582 statically, Exim will refuse to build. If configured as ref:user then Exim
583 will exit shortly after start-up. If you must shoot yourself in the foot,
584 then henceforth you will have to maintain your own local patches to strip
587 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
588 condition logic to determine truth/failure and will fail to expand many
589 strings, bool_lax{} uses the router condition logic, where most strings
591 Note: bool{00} is false, bool_lax{00} is true.
593 9. Routers now support multiple "condition" tests.
595 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
596 Setting this allows an admin to define which entry in the tcpwrappers
597 config file will be used to control access to the daemon. This option
598 is only available when Exim is built with USE_TCP_WRAPPERS. The
599 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
602 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
603 the Exim run-time user, instead of root.
605 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
606 is forced on. This is mitigated by the new build option
607 TRUSTED_CONFIG_LIST which defines a list of configuration files which
608 are trusted; one per line. If a config file is owned by root and matches
609 a pathname in the list, then it may be invoked by the Exim build-time
610 user without Exim relinquishing root privileges.
612 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
613 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
614 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
615 include the main config. As a transition mechanism, we are temporarily
616 providing a work-around: the new build option WHITELIST_D_MACROS provides
617 a colon-separated list of macro names which may be overridden by the Exim
618 run-time user. The values of these macros are constrained to the regex
619 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
625 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
626 writable, the other to locking of MBX folders (not mbox).
628 2. MySQL stored procedures are now supported.
630 3. The dkim_domain transport option is now a list, not a single string, and
631 messages will be signed for each element in the list (discarding
634 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
635 in the presence of multiple character strings within the RR. Prior to 4.70,
636 only the first string would be returned. The dnsdb lookup now, by default,
637 preserves the pre-4.70 semantics, but also now takes an extended output
638 separator specification. The separator can be followed by a semicolon, to
639 concatenate the individual text strings together with no join character,
640 or by a comma and a second separator character, in which case the text
641 strings within a TXT record are joined on that second character.
642 Administrators are reminded that DNS provides no ordering guarantees
643 between multiple records in an RRset. For example:
645 foo.example. IN TXT "a" "b" "c"
646 foo.example. IN TXT "d" "e" "f"
648 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
649 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
650 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
656 1. Native DKIM support without an external library.
657 (Note that if no action to prevent it is taken, a straight upgrade will
658 result in DKIM verification of all signed incoming emails. See spec
659 for details on conditionally disabling)
661 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
663 3. There is now a bool{} expansion condition which maps certain strings to
664 true/false condition values (most likely of use in conjunction with the
665 and{} expansion operator).
667 4. The $spam_score, $spam_bar and $spam_report variables are now available
670 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
671 options, provided that Exim is invoked by an admin_user.
673 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
674 which increases compatibility with older clients at the cost of decreased
675 security. Don't set this unless you need to support such clients.
677 7. There is a new expansion operator, ${randint:...} which will produce a
678 "random" number less than the supplied integer. This randomness is
679 not guaranteed to be cryptographically strong, but depending upon how
680 Exim was built may be better than the most naive schemes.
682 8. Exim now explicitly ensures that SHA256 is available when linked against
685 9. The transport_filter_timeout option now applies to SMTP transports too.
691 1. Preliminary DKIM support in Experimental.
697 1. The body_linecount and body_zerocount C variables are now exported in the
700 2. When a dnslists lookup succeeds, the key that was looked up is now placed
701 in $dnslist_matched. When the key is an IP address, it is not reversed in
702 this variable (though it is, of course, in the actual lookup). In simple
705 deny dnslists = spamhaus.example
707 the key is also available in another variable (in this case,
708 $sender_host_address). In more complicated cases, however, this is not
709 true. For example, using a data lookup might generate a dnslists lookup
712 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
714 If this condition succeeds, the value in $dnslist_matched might be
715 192.168.6.7 (for example).
717 3. Authenticators now have a client_condition option. When Exim is running as
718 a client, it skips an authenticator whose client_condition expansion yields
719 "0", "no", or "false". This can be used, for example, to skip plain text
720 authenticators when the connection is not encrypted by a setting such as:
722 client_condition = ${if !eq{$tls_cipher}{}}
724 Note that the 4.67 documentation states that $tls_cipher contains the
725 cipher used for incoming messages. In fact, during SMTP delivery, it
726 contains the cipher used for the delivery. The same is true for
729 4. There is now a -Mvc <message-id> option, which outputs a copy of the
730 message to the standard output, in RFC 2822 format. The option can be used
731 only by an admin user.
733 5. There is now a /noupdate option for the ratelimit ACL condition. It
734 computes the rate and checks the limit as normal, but it does not update
735 the saved data. This means that, in relevant ACLs, it is possible to lookup
736 the existence of a specified (or auto-generated) ratelimit key without
737 incrementing the ratelimit counter for that key.
739 In order for this to be useful, another ACL entry must set the rate
740 for the same key somewhere (otherwise it will always be zero).
745 # Read the rate; if it doesn't exist or is below the maximum
747 deny ratelimit = 100 / 5m / strict / noupdate
748 log_message = RATE: $sender_rate / $sender_rate_period \
749 (max $sender_rate_limit)
751 [... some other logic and tests...]
753 warn ratelimit = 100 / 5m / strict / per_cmd
754 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
755 (max $sender_rate_limit)
756 condition = ${if le{$sender_rate}{$sender_rate_limit}}
760 6. The variable $max_received_linelength contains the number of bytes in the
761 longest line that was received as part of the message, not counting the
762 line termination character(s).
764 7. Host lists can now include +ignore_defer and +include_defer, analagous to
765 +ignore_unknown and +include_unknown. These options should be used with
766 care, probably only in non-critical host lists such as whitelists.
768 8. There's a new option called queue_only_load_latch, which defaults true.
769 If set false when queue_only_load is greater than zero, Exim re-evaluates
770 the load for each incoming message in an SMTP session. Otherwise, once one
771 message is queued, the remainder are also.
773 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
774 cases when an SMTP session ends without sending QUIT. However, when Exim
775 itself is is bad trouble, such as being unable to write to its log files,
776 this ACL is not run, because it might try to do things (such as write to
777 log files) that make the situation even worse.
779 Like the QUIT ACL, this new ACL is provided to make it possible to gather
780 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
781 modifier is forbidden in this ACL.
783 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
784 to a string that indicates the reason for the termination of the SMTP
785 connection. The possible values are:
787 acl-drop Another ACL issued a "drop" command
788 bad-commands Too many unknown or non-mail commands
789 command-timeout Timeout while reading SMTP commands
790 connection-lost The SMTP connection has been lost
791 data-timeout Timeout while reading message data
792 local-scan-error The local_scan() function crashed
793 local-scan-timeout The local_scan() function timed out
794 signal-exit SIGTERM or SIGINT
795 synchronization-error SMTP synchronization error
796 tls-failed TLS failed to start
798 In most cases when an SMTP connection is closed without having received
799 QUIT, Exim sends an SMTP response message before actually closing the
800 connection. With the exception of acl-drop, the default message can be
801 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
802 "drop" verb in another ACL, it is the message from the other ACL that is
805 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
806 servers with individual queries. This is done by starting the query with
807 "servers=x:y:z;", where each item in the list may take one of two forms:
809 (1) If it is just a host name, the appropriate global option (mysql_servers
810 or pgsql_servers) is searched for a host of the same name, and the
811 remaining parameters (database, user, password) are taken from there.
813 (2) If it contains any slashes, it is taken as a complete parameter set.
815 The list of servers is used in exactly the same was as the global list.
816 Once a connection to a server has happened and a query has been
817 successfully executed, processing of the lookup ceases.
819 This feature is intended for use in master/slave situations where updates
820 are occurring, and one wants to update a master rather than a slave. If the
821 masters are in the list for reading, you might have:
823 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
825 In an updating lookup, you could then write
827 ${lookup mysql{servers=master; UPDATE ...}
829 If, on the other hand, the master is not to be used for reading lookups:
831 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
833 you can still update the master by
835 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
837 11. The message_body_newlines option (default FALSE, for backwards
838 compatibility) can be used to control whether newlines are present in
839 $message_body and $message_body_end. If it is FALSE, they are replaced by
846 1. There is a new log selector called smtp_no_mail, which is not included in
847 the default setting. When it is set, a line is written to the main log
848 whenever an accepted SMTP connection terminates without having issued a
851 2. When an item in a dnslists list is followed by = and & and a list of IP
852 addresses, the behaviour was not clear when the lookup returned more than
853 one IP address. This has been solved by the addition of == and =& for "all"
854 rather than the default "any" matching.
856 3. Up till now, the only control over which cipher suites GnuTLS uses has been
857 for the cipher algorithms. New options have been added to allow some of the
858 other parameters to be varied.
860 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
861 set, Exim compiles a runtime option called disable_fsync.
863 5. There is a new variable called $smtp_count_at_connection_start.
865 6. There's a new control called no_pipelining.
867 7. There are two new variables called $sending_ip_address and $sending_port.
868 These are set whenever an SMTP connection to another host has been set up.
870 8. The expansion of the helo_data option in the smtp transport now happens
871 after the connection to the server has been made.
873 9. There is a new expansion operator ${rfc2047d: that decodes strings that
874 are encoded as per RFC 2047.
876 10. There is a new log selector called "pid", which causes the current process
877 id to be added to every log line, in square brackets, immediately after the
880 11. Exim has been modified so that it flushes SMTP output before implementing
881 a delay in an ACL. It also flushes the output before performing a callout,
882 as this can take a substantial time. These behaviours can be disabled by
883 obeying control = no_delay_flush or control = no_callout_flush,
884 respectively, at some earlier stage of the connection.
886 12. There are two new expansion conditions that iterate over a list. They are
887 called forany and forall.
889 13. There's a new global option called dsn_from that can be used to vary the
890 contents of From: lines in bounces and other automatically generated
891 messages ("delivery status notifications" - hence the name of the option).
893 14. The smtp transport has a new option called hosts_avoid_pipelining.
895 15. By default, exigrep does case-insensitive matches. There is now a -I option
896 that makes it case-sensitive.
898 16. A number of new features ("addresses", "map", "filter", and "reduce") have
899 been added to string expansions to make it easier to process lists of
900 items, typically addresses.
902 17. There's a new ACL modifier called "continue". It does nothing of itself,
903 and processing of the ACL always continues with the next condition or
904 modifier. It is provided so that the side effects of expanding its argument
907 18. It is now possible to use newline and other control characters (those with
908 values less than 32, plus DEL) as separators in lists.
910 19. The exigrep utility now has a -v option, which inverts the matching
913 20. The host_find_failed option in the manualroute router can now be set to
920 No new features were added to 4.66.
926 No new features were added to 4.65.
932 1. ACL variables can now be given arbitrary names, as long as they start with
933 "acl_c" or "acl_m" (for connection variables and message variables), are at
934 least six characters long, with the sixth character being either a digit or
937 2. There is a new ACL modifier called log_reject_target. It makes it possible
938 to specify which logs are used for messages about ACL rejections.
940 3. There is a new authenticator called "dovecot". This is an interface to the
941 authentication facility of the Dovecot POP/IMAP server, which can support a
942 number of authentication methods.
944 4. The variable $message_headers_raw provides a concatenation of all the
945 messages's headers without any decoding. This is in contrast to
946 $message_headers, which does RFC2047 decoding on the header contents.
948 5. In a DNS black list, if two domain names, comma-separated, are given, the
949 second is used first to do an initial check, making use of any IP value
950 restrictions that are set. If there is a match, the first domain is used,
951 without any IP value restrictions, to get the TXT record.
953 6. All authenticators now have a server_condition option.
955 7. There is a new command-line option called -Mset. It is useful only in
956 conjunction with -be (that is, when testing string expansions). It must be
957 followed by a message id; Exim loads the given message from its spool
958 before doing the expansions.
960 8. Another similar new command-line option is called -bem. It operates like
961 -be except that it must be followed by the name of a file that contains a
964 9. When an address is delayed because of a 4xx response to a RCPT command, it
965 is now the combination of sender and recipient that is delayed in
966 subsequent queue runs until its retry time is reached.
968 10. Unary negation and the bitwise logical operators and, or, xor, not, and
969 shift, have been added to the eval: and eval10: expansion items.
971 11. The variables $interface_address and $interface_port have been renamed
972 as $received_ip_address and $received_port, to make it clear that they
973 relate to message reception rather than delivery. (The old names remain
974 available for compatibility.)
976 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
977 to vary the message that is sent when an SMTP command is accepted.
983 1. There is a new Boolean option called filter_prepend_home for the redirect
986 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
987 start of receiving a non-SMTP message, before any of the message has been
990 3. When an SMTP error message is specified in a "message" modifier in an ACL,
991 or in a :fail: or :defer: message in a redirect router, Exim now checks the
992 start of the message for an SMTP error code.
994 4. There is a new parameter for LDAP lookups called "referrals", which takes
995 one of the settings "follow" (the default) or "nofollow".
997 5. Version 20070721.2 of exipick now included, offering these new options:
999 After all other sorting options have bee processed, reverse order
1000 before displaying messages (-R is synonym).
1002 Randomize order of matching messages before displaying.
1004 Instead of displaying the matching messages, display the sum
1006 --sort <variable>[,<variable>...]
1007 Before displaying matching messages, sort the messages according to
1008 each messages value for each variable.
1010 Negate the value for every test (returns inverse output from the
1011 same criteria without --not).
1017 1. The ${readsocket expansion item now supports Internet domain sockets as well
1018 as Unix domain sockets. If the first argument begins "inet:", it must be of
1019 the form "inet:host:port". The port is mandatory; it may be a number or the
1020 name of a TCP port in /etc/services. The host may be a name, or it may be an
1021 IP address. An ip address may optionally be enclosed in square brackets.
1022 This is best for IPv6 addresses. For example:
1024 ${readsocket{inet:[::1]:1234}{<request data>}...
1026 Only a single host name may be given, but if looking it up yield more than
1027 one IP address, they are each tried in turn until a connection is made. Once
1028 a connection has been made, the behaviour is as for ${readsocket with a Unix
1031 2. If a redirect router sets up file or pipe deliveries for more than one
1032 incoming address, and the relevant transport has batch_max set greater than
1033 one, a batch delivery now occurs.
1035 3. The appendfile transport has a new option called maildirfolder_create_regex.
1036 Its value is a regular expression. For a maildir delivery, this is matched
1037 against the maildir directory; if it matches, Exim ensures that a
1038 maildirfolder file is created alongside the new, cur, and tmp directories.
1044 The documentation is up-to-date for the 4.61 release. Major new features since
1045 the 4.60 release are:
1047 . An option called disable_ipv6, to disable the use of IPv6 completely.
1049 . An increase in the number of ACL variables to 20 of each type.
1051 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
1052 $2, $3, (though those are still set) because the numeric variables get used
1053 for other things in complicated expansions.
1055 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1057 . It is possible to use setclassresources() on some BSD OS to control the
1058 resources used in pipe deliveries.
1060 . A new ACL modifier called add_header, which can be used with any verb.
1062 . More errors are detectable in retry rules.
1064 There are a number of other additions too.
1070 The documentation is up-to-date for the 4.60 release. Major new features since
1071 the 4.50 release are:
1073 . Support for SQLite.
1075 . Support for IGNOREQUOTA in LMTP.
1077 . Extensions to the "submission mode" features.
1079 . Support for Client SMTP Authorization (CSA).
1081 . Support for ratelimiting hosts and users.
1083 . New expansion items to help with the BATV "prvs" scheme.
1085 . A "match_ip" condition, that matches an IP address against a list.
1087 There are many more minor changes.
git://git.exim.org / exim.git / blob