4 This file contains descriptions of new features that have been added to Exim.
5 Before a formal release, there may be quite a lot of detail so that people can
6 test from the snapshots or the CVS before the documentation is updated. Once
7 the documentation is updated, this file is reduced to a short list.
12 1. The new perl_taintmode option allows to run the embedded perl
13 interpreter in taint mode.
15 2. New log_selector: dnssec, adds a "DS" tag to acceptance and delivery lines.
17 3. Speculative debugging, via a "kill" option to the "control=debug" ACL
20 4. New expansion item ${sha3:<string>} / ${sha3_<N>:<string>}.
21 N can be 224, 256 (default), 384, 512.
22 With GnuTLS 3.5.0 or later, only.
24 5. Facility for named queues: A commandline argument can specify
25 the queue name for a queue operation, and an ACL modifier can set
26 the queue to be used for a message. A $queue_name variable gives
29 6. New expansion operators base32/base32d.
31 7. The CHUNKING ESMTP extension from RFC 3030. May give some slight
32 performance increase and network load decrease. Main config option
33 chunking_advertise_hosts, and smtp transport option hosts_try_chunking
36 8. LMDB lookup support, as Experimental. Patch supplied by Andrew Colin Kissa.
38 9. Expansion operator escape8bit, like escape but not touching newline etc..
40 10. Feature macros, generated from compile options. All start with "_HAVE_"
41 and go on with some roughly recognisable name. Driver macros, for
42 router, transport and authentication drivers; names starting with "_DRVR_".
43 Option macros, for each configuration-file option; all start with "_OPT_".
44 Use the "-bP macros" command-line option to see what is present.
46 11. Integer values for options can take a "G" multiplier.
48 12. defer=pass option for the ACL control cutthrough_delivery, to reflect 4xx
49 returns from the target back to the initiator, rather than spooling the
56 1. The ACL conditions regex and mime_regex now capture substrings
57 into numeric variables $regex1 to 9, like the "match" expansion condition.
59 2. New $callout_address variable records the address used for a spam=,
60 malware= or verify= callout.
62 3. Transports now take a "max_parallel" option, to limit concurrency.
64 4. Expansion operators ${ipv6norm:<string>} and ${ipv6denorm:<string>}.
65 The latter expands to a 8-element colon-sep set of hex digits including
66 leading zeroes. A trailing ipv4-style dotted-decimal set is converted
67 to hex. Pure ipv4 addresses are converted to IPv4-mapped IPv6.
68 The former operator strips leading zeroes and collapses the longest
69 set of 0-groups to a double-colon.
71 5. New "-bP config" support, to dump the effective configuration.
73 6. New $dkim_key_length variable.
75 7. New base64d and base64 expansion items (the existing str2b64 being a
76 synonym of the latter). Add support in base64 for certificates.
78 8. New main configuration option "bounce_return_linesize_limit" to
79 avoid oversize bodies in bounces. The dafault value matches RFC
82 9. New $initial_cwd expansion variable.
88 1. Support for using the system standard CA bundle.
90 2. New expansion items $config_file, $config_dir, containing the file
91 and directory name of the main configuration file. Also $exim_version.
93 3. New "malware=" support for Avast.
95 4. New "spam=" variant option for Rspamd.
97 5. Assorted options on malware= and spam= scanners.
99 6. A commandline option to write a comment into the logfile.
101 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
102 be configured to make connections via socks5 proxies.
104 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
105 the transmission of UTF-8 envelope addresses.
107 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
108 used encoding of Maildir folder names.
110 10. A logging option for slow DNS lookups.
112 11. New ${env {<variable>}} expansion.
114 12. A non-SMTP authenticator using information from TLS client certificates.
116 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
117 Patch originally by Wolfgang Breyha.
119 14. Main option "dns_trust_aa" for trusting your local nameserver at the
120 same level as DNSSEC.
126 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
127 DANE smtp draft to assess a secure chain of trust of the certificate
128 used to establish the TLS connection based on a TLSA record in the
129 domain of the sender.
131 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
132 and several new events have been created. The reason is because it has
133 been expanded beyond just firing events during the transport phase. Any
134 existing TPDA transport options will have to be rewritten to use a new
135 $event_name expansion variable in a condition. Refer to the
136 experimental-spec.txt for details and examples.
138 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
139 server certs used for TLS match the result of the MX lookup. It does
140 not use the same mechanism as DANE.
150 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
151 configured to expect an initial header from a proxy that will make the
152 actual external source IP:host be used in exim instead of the IP of the
153 proxy that is connecting to it.
155 2. New verify option header_names_ascii, which will check to make sure
156 there are no non-ASCII characters in header names. Exim itself handles
157 those non-ASCII characters, but downstream apps may not, so Exim can
158 detect and reject if those characters are present.
160 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
161 codepoints with valid ones.
163 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
164 command line and matching a regex against the return data for trigger
165 and a second regex to extract malware_name. The mail spoolfile name can
166 be included in the command line.
168 5. The smtp transport now supports options "tls_verify_hosts" and
169 "tls_try_verify_hosts". If either is set the certificate verification
170 is split from the encryption operation. The default remains that a failed
171 verification cancels the encryption.
173 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
174 lookup can now set a list of servers to use that is different from the
177 7. New command-line option -C for exiqgrep to specify alternate exim.conf
178 file when searching the queue.
180 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
182 9. Support for DNSSEC on outbound connections.
184 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
185 "certextract" to extract fields from them. Hash operators md5 and sha1
186 work over them for generating fingerprints, and a new sha256 operator
189 11. PRDR is now supported dy default.
191 12. OCSP stapling is now supported by default.
193 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
194 Delivery Status Notification messages in MIME format, and negociate
195 DSN features per RFC 3461.
201 1. New command-line option -bI:sieve will list all supported sieve extensions
202 of this Exim build on standard output, one per line.
203 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
204 query this to establish the correct list to include in the protocol's
205 SIEVE capability line.
207 2. If the -n option is combined with the -bP option, then the name of an
208 emitted option is not output, only the value (if visible to you).
209 For instance, "exim -n -bP pid_file_path" should just emit a pathname
210 followed by a newline, and no other text.
212 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
213 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
214 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
215 acceptable for security. (Option accepted but ignored if using OpenSSL).
216 Defaults to 1024, the old value. May be lowered only to 512, or raised as
217 far as you like. Raising this may hinder TLS interoperability with other
218 sites and is not currently recommended. Lowering this will permit you to
219 establish a TLS session which is not as secure as you might like.
221 Unless you really know what you are doing, leave it alone.
223 4. If not built with DISABLE_DNSSEC, Exim now has the main option
224 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
225 to send the DO flag to your recursive resolver. If you have a recursive
226 resolver, which can set the Authenticated Data (AD) flag in results, Exim
227 can now detect this. Exim does not perform validation itself, instead
228 relying upon a trusted path to the resolver.
230 Current status: work-in-progress; $sender_host_dnssec variable added.
232 5. DSCP support for outbound connections: on a transport using the smtp driver,
233 set "dscp = ef", for instance, to cause the connections to have the relevant
234 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
236 Similarly for inbound connections, there is a new control modifier, dscp,
237 so "warn control = dscp/ef" in the connect ACL, or after authentication.
239 Supported values depend upon system libraries. "exim -bI:dscp" to list the
240 ones Exim knows of. You can also set a raw number 0..0x3F.
242 6. The -G command-line flag is no longer ignored; it is now equivalent to an
243 ACL setting "control = suppress_local_fixups". The -L command-line flag
244 is now accepted and forces use of syslog, with the provided tag as the
245 process name. A few other flags used by Sendmail are now accepted and
248 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
249 ACL modifier; works for single-recipient mails which are recieved on and
250 deliverable via SMTP. Using the connection made for a recipient verify,
251 if requested before the verify, or a new one made for the purpose while
252 the inbound connection is still active. The bulk of the mail item is copied
253 direct from the inbound socket to the outbound (as well as the spool file).
254 When the source notifies the end of data, the data acceptance by the destination
255 is negociated before the acceptance is sent to the source. If the destination
256 does not accept the mail item, for example due to content-scanning, the item
257 is not accepted from the source and therefore there is no need to generate
258 a bounce mail. This is of benefit when providing a secondary-MX service.
259 The downside is that delays are under the control of the ultimate destination
262 The Recieved-by: header on items delivered by cutthrough is generated
263 early in reception rather than at the end; this will affect any timestamp
264 included. The log line showing delivery is recorded before that showing
265 reception; it uses a new ">>" tag instead of "=>".
267 To support the feature, verify-callout connections can now use ESMTP and TLS.
268 The usual smtp transport options are honoured, plus a (new, default everything)
269 hosts_verify_avoid_tls.
271 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
272 for specific access to the information for each connection. The old names
273 are present for now but deprecated.
275 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
277 8. New expansion operators ${listnamed:name} to get the content of a named list
278 and ${listcount:string} to count the items in a list.
280 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
281 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
282 modules. For some situations this is desirable, but we expect admin in
283 those situations to know they want the feature. More commonly, it means
284 that GUI user modules get loaded and are broken by the setuid Exim being
285 unable to access files specified in environment variables and passed
286 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
287 unless this new option is set.
289 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
290 so have also added a build option which can be used to build Exim with GnuTLS
291 but without trying to use any kind of PKCS11 support. Uncomment this in the
294 AVOID_GNUTLS_PKCS11=yes
296 10. The "acl = name" condition on an ACL now supports optional arguments.
297 New expansion item "${acl {name}{arg}...}" and expansion condition
298 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
299 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
300 Variable $acl_narg contains the number of arguments. If the ACL sets
301 a "message =" value this becomes the result of the expansion item,
302 or the value of $value for the expansion condition. If the ACL returns
303 accept the expansion condition is true; if reject, false. A defer
304 return results in a forced fail.
306 11. Routers and transports can now have multiple headers_add and headers_remove
307 option lines. The concatenated list is used.
309 12. New ACL modifier "remove_header" can remove headers before message gets
310 handled by routers/transports.
312 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
313 "aaaa" and "a" lookups is done and the full set of results returned.
315 14. New expansion variable $headers_added with content from ACL add_header
316 modifier (but not yet added to message).
318 15. New 8bitmime status logging option for received messages. Log field "M8S".
320 16. New authenticated_sender logging option, adding to log field "A".
322 17. New expansion variables $router_name and $transport_name. Useful
323 particularly for debug_print as -bt commandline option does not
324 require privilege whereas -d does.
326 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
327 proposed extension to SMTP from Eric Hall.
329 19. The pipe transport has gained the force_command option, to allow
330 decorating commands from user .forward pipe aliases with prefix
331 wrappers, for instance.
333 20. Callout connections can now AUTH; the same controls as normal delivery
336 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
337 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
338 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
339 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
340 dmarc_status. It adds new control flags dmarc_disable_verify and
341 dmarc_enable_forensic.
343 22. Add expansion variable $authenticated_fail_id, which is the username
344 provided to the authentication method which failed. It is available
345 for use in subsequent ACL processing (typically quit or notquit ACLs).
347 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
350 24. New ${hexquote:..string..} expansion operator converts non-printable
351 characters in the string to \xNN form.
353 25. Experimental TPDA (Transport Post Delivery Action) function added.
354 Patch provided by Axel Rau.
356 26. Experimental Redis lookup added. Patch provided by Warren Baker.
362 1. New authenticator driver, "gsasl". Server-only (at present).
363 This is a SASL interface, licensed under GPL, which can be found at
364 http://www.gnu.org/software/gsasl/.
365 This system does not provide sources of data for authentication, so
366 careful use needs to be made of the conditions in Exim.
368 2. New authenticator driver, "heimdal_gssapi". Server-only.
369 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
370 is no longer honoured for setuid programs by Heimdal. Use the
371 "server_keytab" option to point to the keytab.
373 3. The "pkg-config" system can now be used when building Exim to reference
374 cflags and library information for lookups and authenticators, rather
375 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
376 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
377 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
379 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
380 find the headers and libraries for PCRE.
382 4. New expansion variable $tls_bits.
384 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
385 be joined together with ASCII NUL characters to construct the key to pass
386 into the DBM library. Can be used with gsasl to access sasldb2 files as
389 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
391 Avoid release 1.0.1a if you can. Note that the default value of
392 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
393 increased susceptibility to attack. This may still have interoperability
394 implications for very old clients (see version 4.31 change 37) but
395 administrators can choose to make the trade-off themselves and restore
396 compatibility at the cost of session security.
398 7. Use of the new expansion variable $tls_sni in the main configuration option
399 tls_certificate will cause Exim to re-expand the option, if the client
400 sends the TLS Server Name Indication extension, to permit choosing a
401 different certificate; tls_privatekey will also be re-expanded. You must
402 still set these options to expand to valid files when $tls_sni is not set.
404 The SMTP Transport has gained the option tls_sni, which will set a hostname
405 for outbound TLS sessions, and set $tls_sni too.
407 A new log_selector, +tls_sni, has been added, to log received SNI values
408 for Exim as a server.
410 8. The existing "accept_8bitmime" option now defaults to true. This means
411 that Exim is deliberately not strictly RFC compliant. We're following
412 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
413 Those who disagree, or know that they are talking to mail servers that,
414 even today, are not 8-bit clean, need to turn off this option.
416 9. Exim can now be started with -bw (with an optional timeout, given as
417 -bw<timespec>). With this, stdin at startup is a socket that is
418 already listening for connections. This has a more modern name of
419 "socket activation", but forcing the activated socket to fd 0. We're
420 interested in adding more support for modern variants.
422 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
423 for numbers indicates multiplication by 1024^3.
425 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
426 gnutls_require_mac & gnutls_require_protocols are no longer supported.
427 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
428 string, documentation for which is at:
429 http://www.gnutls.org/manual/html_node/Priority-Strings.html
431 SNI support has been added to Exim's GnuTLS integration too.
433 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
434 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
436 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
437 is now available. If the contents of the file are valid, then Exim will
438 send that back in response to a TLS status request; this is OCSP Stapling.
439 Exim will not maintain the contents of the file in any way: administrators
440 are responsible for ensuring that it is up-to-date.
442 See "experimental-spec.txt" for more details.
444 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
445 identically to TXT record lookups.
447 14. New expansion variable $tod_epoch_l for higher-precision time.
449 15. New global option tls_dh_max_bits, defaulting to current value of NSS
450 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
451 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
453 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
454 Option can now be a path or an identifier for a standard prime.
455 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
456 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
459 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
460 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
461 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
467 1. New options for the ratelimit ACL condition: /count= and /unique=.
468 The /noupdate option has been replaced by a /readonly option.
470 2. The SMTP transport's protocol option may now be set to "smtps", to
471 use SSL-on-connect outbound.
473 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
474 there is a problem talking to the AV scanner, or the AV scanner running.
476 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
477 and check if the search item is a member of the list. This does not
478 support named lists, but does subject the list part to string expansion.
480 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
481 built, Exim no longer performs string expansion on the second string of
482 the match_* expansion conditions: "match_address", "match_domain",
483 "match_ip" & "match_local_part". Named lists can still be used.
489 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
490 or off in the resolver library.
496 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
497 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
498 libraries. The following global options have been added in support of
499 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
500 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
502 2. The pipe transport now takes a boolean option, "freeze_signal", default
503 false. When true, if the external delivery command exits on a signal then
504 Exim will freeze the message in the queue, instead of generating a bounce.
506 3. Log filenames may now use %M as an escape, instead of %D (still available).
507 The %M pattern expands to yyyymm, providing month-level resolution.
509 4. The $message_linecount variable is now updated for the maildir_tag option,
510 in the same way as $message_size, to reflect the real number of lines,
511 including any header additions or removals from transport.
513 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
514 Exim now selects entries randomly, to better scale in a cluster setup.
520 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
521 the flaw permitted the Exim run-time user to cause root to append to
522 arbitrary files of the attacker's choosing, with the content based
523 on content supplied by the attacker.
525 2. Exim now supports loading some lookup types at run-time, using your
526 platform's dlopen() functionality. This has limited platform support
527 and the intention is not to support every variant, it's limited to
528 dlopen(). This permits the main Exim binary to not be linked against
529 all the libraries needed for all the lookup types.
535 NOTE: this version is not guaranteed backwards-compatible, please read the
536 items below carefully
538 1. A new main configuration option, "openssl_options", is available if Exim
539 is built with SSL support provided by OpenSSL. The option allows
540 administrators to specify OpenSSL options to be used on connections;
541 typically this is to set bug compatibility features which the OpenSSL
542 developers have not enabled by default. There may be security
543 consequences for certain options, so these should not be changed
546 2. A new pipe transport option, "permit_coredumps", may help with problem
547 diagnosis in some scenarios. Note that Exim is typically installed as
548 a setuid binary, which on most OSes will inhibit coredumps by default,
549 so that safety mechanism would have to be overridden for this option to
550 be able to take effect.
552 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
553 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
554 Note that this switches Exim to use a new API ("INSTREAM") and a future
555 release of ClamAV will remove support for the old API ("STREAM").
557 The av_scanner option, when set to "clamd", now takes an optional third
558 part, "local", which causes Exim to pass a filename to ClamAV instead of
559 the file content. This is the same behaviour as when clamd is pointed at
560 a Unix-domain socket. For example:
562 av_scanner = clamd:192.0.2.3 1234:local
564 ClamAV's ExtendedDetectionInfo response format is now handled.
566 4. There is now a -bmalware option, restricted to admin users. This option
567 takes one parameter, a filename, and scans that file with Exim's
568 malware-scanning framework. This is intended purely as a debugging aid
569 to ensure that Exim's scanning is working, not to replace other tools.
570 Note that the ACL framework is not invoked, so if av_scanner references
571 ACL variables without a fallback then this will fail.
573 5. There is a new expansion operator, "reverse_ip", which will reverse IP
574 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
576 ${reverse_ip:192.0.2.4}
578 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
579 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
581 6. There is a new ACL control called "debug", to enable debug logging.
582 This allows selective logging of certain incoming transactions within
583 production environments, with some care. It takes two options, "tag"
584 and "opts"; "tag" is included in the filename of the log and "opts"
585 is used as per the -d<options> command-line option. Examples, which
586 don't all make sense in all contexts:
589 control = debug/tag=.$sender_host_address
590 control = debug/opts=+expand+acl
591 control = debug/tag=.$message_exim_id/opts=+expand
593 7. It has always been implicit in the design and the documentation that
594 "the Exim user" is not root. src/EDITME said that using root was
595 "very strongly discouraged". This is not enough to keep people from
596 shooting themselves in the foot in days when many don't configure Exim
597 themselves but via package build managers. The security consequences of
598 running various bits of network code are severe if there should be bugs in
599 them. As such, the Exim user may no longer be root. If configured
600 statically, Exim will refuse to build. If configured as ref:user then Exim
601 will exit shortly after start-up. If you must shoot yourself in the foot,
602 then henceforth you will have to maintain your own local patches to strip
605 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
606 condition logic to determine truth/failure and will fail to expand many
607 strings, bool_lax{} uses the router condition logic, where most strings
609 Note: bool{00} is false, bool_lax{00} is true.
611 9. Routers now support multiple "condition" tests.
613 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
614 Setting this allows an admin to define which entry in the tcpwrappers
615 config file will be used to control access to the daemon. This option
616 is only available when Exim is built with USE_TCP_WRAPPERS. The
617 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
620 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
621 the Exim run-time user, instead of root.
623 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
624 is forced on. This is mitigated by the new build option
625 TRUSTED_CONFIG_LIST which defines a list of configuration files which
626 are trusted; one per line. If a config file is owned by root and matches
627 a pathname in the list, then it may be invoked by the Exim build-time
628 user without Exim relinquishing root privileges.
630 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
631 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
632 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
633 include the main config. As a transition mechanism, we are temporarily
634 providing a work-around: the new build option WHITELIST_D_MACROS provides
635 a colon-separated list of macro names which may be overridden by the Exim
636 run-time user. The values of these macros are constrained to the regex
637 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
643 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
644 writable, the other to locking of MBX folders (not mbox).
646 2. MySQL stored procedures are now supported.
648 3. The dkim_domain transport option is now a list, not a single string, and
649 messages will be signed for each element in the list (discarding
652 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
653 in the presence of multiple character strings within the RR. Prior to 4.70,
654 only the first string would be returned. The dnsdb lookup now, by default,
655 preserves the pre-4.70 semantics, but also now takes an extended output
656 separator specification. The separator can be followed by a semicolon, to
657 concatenate the individual text strings together with no join character,
658 or by a comma and a second separator character, in which case the text
659 strings within a TXT record are joined on that second character.
660 Administrators are reminded that DNS provides no ordering guarantees
661 between multiple records in an RRset. For example:
663 foo.example. IN TXT "a" "b" "c"
664 foo.example. IN TXT "d" "e" "f"
666 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
667 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
668 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
674 1. Native DKIM support without an external library.
675 (Note that if no action to prevent it is taken, a straight upgrade will
676 result in DKIM verification of all signed incoming emails. See spec
677 for details on conditionally disabling)
679 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
681 3. There is now a bool{} expansion condition which maps certain strings to
682 true/false condition values (most likely of use in conjunction with the
683 and{} expansion operator).
685 4. The $spam_score, $spam_bar and $spam_report variables are now available
688 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
689 options, provided that Exim is invoked by an admin_user.
691 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
692 which increases compatibility with older clients at the cost of decreased
693 security. Don't set this unless you need to support such clients.
695 7. There is a new expansion operator, ${randint:...} which will produce a
696 "random" number less than the supplied integer. This randomness is
697 not guaranteed to be cryptographically strong, but depending upon how
698 Exim was built may be better than the most naive schemes.
700 8. Exim now explicitly ensures that SHA256 is available when linked against
703 9. The transport_filter_timeout option now applies to SMTP transports too.
709 1. Preliminary DKIM support in Experimental.
715 1. The body_linecount and body_zerocount C variables are now exported in the
718 2. When a dnslists lookup succeeds, the key that was looked up is now placed
719 in $dnslist_matched. When the key is an IP address, it is not reversed in
720 this variable (though it is, of course, in the actual lookup). In simple
723 deny dnslists = spamhaus.example
725 the key is also available in another variable (in this case,
726 $sender_host_address). In more complicated cases, however, this is not
727 true. For example, using a data lookup might generate a dnslists lookup
730 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
732 If this condition succeeds, the value in $dnslist_matched might be
733 192.168.6.7 (for example).
735 3. Authenticators now have a client_condition option. When Exim is running as
736 a client, it skips an authenticator whose client_condition expansion yields
737 "0", "no", or "false". This can be used, for example, to skip plain text
738 authenticators when the connection is not encrypted by a setting such as:
740 client_condition = ${if !eq{$tls_cipher}{}}
742 Note that the 4.67 documentation states that $tls_cipher contains the
743 cipher used for incoming messages. In fact, during SMTP delivery, it
744 contains the cipher used for the delivery. The same is true for
747 4. There is now a -Mvc <message-id> option, which outputs a copy of the
748 message to the standard output, in RFC 2822 format. The option can be used
749 only by an admin user.
751 5. There is now a /noupdate option for the ratelimit ACL condition. It
752 computes the rate and checks the limit as normal, but it does not update
753 the saved data. This means that, in relevant ACLs, it is possible to lookup
754 the existence of a specified (or auto-generated) ratelimit key without
755 incrementing the ratelimit counter for that key.
757 In order for this to be useful, another ACL entry must set the rate
758 for the same key somewhere (otherwise it will always be zero).
763 # Read the rate; if it doesn't exist or is below the maximum
765 deny ratelimit = 100 / 5m / strict / noupdate
766 log_message = RATE: $sender_rate / $sender_rate_period \
767 (max $sender_rate_limit)
769 [... some other logic and tests...]
771 warn ratelimit = 100 / 5m / strict / per_cmd
772 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
773 (max $sender_rate_limit)
774 condition = ${if le{$sender_rate}{$sender_rate_limit}}
778 6. The variable $max_received_linelength contains the number of bytes in the
779 longest line that was received as part of the message, not counting the
780 line termination character(s).
782 7. Host lists can now include +ignore_defer and +include_defer, analagous to
783 +ignore_unknown and +include_unknown. These options should be used with
784 care, probably only in non-critical host lists such as whitelists.
786 8. There's a new option called queue_only_load_latch, which defaults true.
787 If set false when queue_only_load is greater than zero, Exim re-evaluates
788 the load for each incoming message in an SMTP session. Otherwise, once one
789 message is queued, the remainder are also.
791 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
792 cases when an SMTP session ends without sending QUIT. However, when Exim
793 itself is is bad trouble, such as being unable to write to its log files,
794 this ACL is not run, because it might try to do things (such as write to
795 log files) that make the situation even worse.
797 Like the QUIT ACL, this new ACL is provided to make it possible to gather
798 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
799 modifier is forbidden in this ACL.
801 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
802 to a string that indicates the reason for the termination of the SMTP
803 connection. The possible values are:
805 acl-drop Another ACL issued a "drop" command
806 bad-commands Too many unknown or non-mail commands
807 command-timeout Timeout while reading SMTP commands
808 connection-lost The SMTP connection has been lost
809 data-timeout Timeout while reading message data
810 local-scan-error The local_scan() function crashed
811 local-scan-timeout The local_scan() function timed out
812 signal-exit SIGTERM or SIGINT
813 synchronization-error SMTP synchronization error
814 tls-failed TLS failed to start
816 In most cases when an SMTP connection is closed without having received
817 QUIT, Exim sends an SMTP response message before actually closing the
818 connection. With the exception of acl-drop, the default message can be
819 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
820 "drop" verb in another ACL, it is the message from the other ACL that is
823 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
824 servers with individual queries. This is done by starting the query with
825 "servers=x:y:z;", where each item in the list may take one of two forms:
827 (1) If it is just a host name, the appropriate global option (mysql_servers
828 or pgsql_servers) is searched for a host of the same name, and the
829 remaining parameters (database, user, password) are taken from there.
831 (2) If it contains any slashes, it is taken as a complete parameter set.
833 The list of servers is used in exactly the same was as the global list.
834 Once a connection to a server has happened and a query has been
835 successfully executed, processing of the lookup ceases.
837 This feature is intended for use in master/slave situations where updates
838 are occurring, and one wants to update a master rather than a slave. If the
839 masters are in the list for reading, you might have:
841 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
843 In an updating lookup, you could then write
845 ${lookup mysql{servers=master; UPDATE ...}
847 If, on the other hand, the master is not to be used for reading lookups:
849 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
851 you can still update the master by
853 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
855 11. The message_body_newlines option (default FALSE, for backwards
856 compatibility) can be used to control whether newlines are present in
857 $message_body and $message_body_end. If it is FALSE, they are replaced by
864 1. There is a new log selector called smtp_no_mail, which is not included in
865 the default setting. When it is set, a line is written to the main log
866 whenever an accepted SMTP connection terminates without having issued a
869 2. When an item in a dnslists list is followed by = and & and a list of IP
870 addresses, the behaviour was not clear when the lookup returned more than
871 one IP address. This has been solved by the addition of == and =& for "all"
872 rather than the default "any" matching.
874 3. Up till now, the only control over which cipher suites GnuTLS uses has been
875 for the cipher algorithms. New options have been added to allow some of the
876 other parameters to be varied.
878 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
879 set, Exim compiles a runtime option called disable_fsync.
881 5. There is a new variable called $smtp_count_at_connection_start.
883 6. There's a new control called no_pipelining.
885 7. There are two new variables called $sending_ip_address and $sending_port.
886 These are set whenever an SMTP connection to another host has been set up.
888 8. The expansion of the helo_data option in the smtp transport now happens
889 after the connection to the server has been made.
891 9. There is a new expansion operator ${rfc2047d: that decodes strings that
892 are encoded as per RFC 2047.
894 10. There is a new log selector called "pid", which causes the current process
895 id to be added to every log line, in square brackets, immediately after the
898 11. Exim has been modified so that it flushes SMTP output before implementing
899 a delay in an ACL. It also flushes the output before performing a callout,
900 as this can take a substantial time. These behaviours can be disabled by
901 obeying control = no_delay_flush or control = no_callout_flush,
902 respectively, at some earlier stage of the connection.
904 12. There are two new expansion conditions that iterate over a list. They are
905 called forany and forall.
907 13. There's a new global option called dsn_from that can be used to vary the
908 contents of From: lines in bounces and other automatically generated
909 messages ("delivery status notifications" - hence the name of the option).
911 14. The smtp transport has a new option called hosts_avoid_pipelining.
913 15. By default, exigrep does case-insensitive matches. There is now a -I option
914 that makes it case-sensitive.
916 16. A number of new features ("addresses", "map", "filter", and "reduce") have
917 been added to string expansions to make it easier to process lists of
918 items, typically addresses.
920 17. There's a new ACL modifier called "continue". It does nothing of itself,
921 and processing of the ACL always continues with the next condition or
922 modifier. It is provided so that the side effects of expanding its argument
925 18. It is now possible to use newline and other control characters (those with
926 values less than 32, plus DEL) as separators in lists.
928 19. The exigrep utility now has a -v option, which inverts the matching
931 20. The host_find_failed option in the manualroute router can now be set to
938 No new features were added to 4.66.
944 No new features were added to 4.65.
950 1. ACL variables can now be given arbitrary names, as long as they start with
951 "acl_c" or "acl_m" (for connection variables and message variables), are at
952 least six characters long, with the sixth character being either a digit or
955 2. There is a new ACL modifier called log_reject_target. It makes it possible
956 to specify which logs are used for messages about ACL rejections.
958 3. There is a new authenticator called "dovecot". This is an interface to the
959 authentication facility of the Dovecot POP/IMAP server, which can support a
960 number of authentication methods.
962 4. The variable $message_headers_raw provides a concatenation of all the
963 messages's headers without any decoding. This is in contrast to
964 $message_headers, which does RFC2047 decoding on the header contents.
966 5. In a DNS black list, if two domain names, comma-separated, are given, the
967 second is used first to do an initial check, making use of any IP value
968 restrictions that are set. If there is a match, the first domain is used,
969 without any IP value restrictions, to get the TXT record.
971 6. All authenticators now have a server_condition option.
973 7. There is a new command-line option called -Mset. It is useful only in
974 conjunction with -be (that is, when testing string expansions). It must be
975 followed by a message id; Exim loads the given message from its spool
976 before doing the expansions.
978 8. Another similar new command-line option is called -bem. It operates like
979 -be except that it must be followed by the name of a file that contains a
982 9. When an address is delayed because of a 4xx response to a RCPT command, it
983 is now the combination of sender and recipient that is delayed in
984 subsequent queue runs until its retry time is reached.
986 10. Unary negation and the bitwise logical operators and, or, xor, not, and
987 shift, have been added to the eval: and eval10: expansion items.
989 11. The variables $interface_address and $interface_port have been renamed
990 as $received_ip_address and $received_port, to make it clear that they
991 relate to message reception rather than delivery. (The old names remain
992 available for compatibility.)
994 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
995 to vary the message that is sent when an SMTP command is accepted.
1001 1. There is a new Boolean option called filter_prepend_home for the redirect
1004 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
1005 start of receiving a non-SMTP message, before any of the message has been
1008 3. When an SMTP error message is specified in a "message" modifier in an ACL,
1009 or in a :fail: or :defer: message in a redirect router, Exim now checks the
1010 start of the message for an SMTP error code.
1012 4. There is a new parameter for LDAP lookups called "referrals", which takes
1013 one of the settings "follow" (the default) or "nofollow".
1015 5. Version 20070721.2 of exipick now included, offering these new options:
1017 After all other sorting options have bee processed, reverse order
1018 before displaying messages (-R is synonym).
1020 Randomize order of matching messages before displaying.
1022 Instead of displaying the matching messages, display the sum
1024 --sort <variable>[,<variable>...]
1025 Before displaying matching messages, sort the messages according to
1026 each messages value for each variable.
1028 Negate the value for every test (returns inverse output from the
1029 same criteria without --not).
1035 1. The ${readsocket expansion item now supports Internet domain sockets as well
1036 as Unix domain sockets. If the first argument begins "inet:", it must be of
1037 the form "inet:host:port". The port is mandatory; it may be a number or the
1038 name of a TCP port in /etc/services. The host may be a name, or it may be an
1039 IP address. An ip address may optionally be enclosed in square brackets.
1040 This is best for IPv6 addresses. For example:
1042 ${readsocket{inet:[::1]:1234}{<request data>}...
1044 Only a single host name may be given, but if looking it up yield more than
1045 one IP address, they are each tried in turn until a connection is made. Once
1046 a connection has been made, the behaviour is as for ${readsocket with a Unix
1049 2. If a redirect router sets up file or pipe deliveries for more than one
1050 incoming address, and the relevant transport has batch_max set greater than
1051 one, a batch delivery now occurs.
1053 3. The appendfile transport has a new option called maildirfolder_create_regex.
1054 Its value is a regular expression. For a maildir delivery, this is matched
1055 against the maildir directory; if it matches, Exim ensures that a
1056 maildirfolder file is created alongside the new, cur, and tmp directories.
1062 The documentation is up-to-date for the 4.61 release. Major new features since
1063 the 4.60 release are:
1065 . An option called disable_ipv6, to disable the use of IPv6 completely.
1067 . An increase in the number of ACL variables to 20 of each type.
1069 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
1070 $2, $3, (though those are still set) because the numeric variables get used
1071 for other things in complicated expansions.
1073 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1075 . It is possible to use setclassresources() on some BSD OS to control the
1076 resources used in pipe deliveries.
1078 . A new ACL modifier called add_header, which can be used with any verb.
1080 . More errors are detectable in retry rules.
1082 There are a number of other additions too.
1088 The documentation is up-to-date for the 4.60 release. Major new features since
1089 the 4.50 release are:
1091 . Support for SQLite.
1093 . Support for IGNOREQUOTA in LMTP.
1095 . Extensions to the "submission mode" features.
1097 . Support for Client SMTP Authorization (CSA).
1099 . Support for ratelimiting hosts and users.
1101 . New expansion items to help with the BATV "prvs" scheme.
1103 . A "match_ip" condition, that matches an IP address against a list.
1105 There are many more minor changes.
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