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. Use the "-bP macros"
42 command-line option to see what is present.
44 11. Integer values for options can take a "G" multiplier.
46 12. defer=pass option for the ACL control cutthrough_delivery, to reflect 4xx
47 returns from the target back to the initiator, rather than spooling the
54 1. The ACL conditions regex and mime_regex now capture substrings
55 into numeric variables $regex1 to 9, like the "match" expansion condition.
57 2. New $callout_address variable records the address used for a spam=,
58 malware= or verify= callout.
60 3. Transports now take a "max_parallel" option, to limit concurrency.
62 4. Expansion operators ${ipv6norm:<string>} and ${ipv6denorm:<string>}.
63 The latter expands to a 8-element colon-sep set of hex digits including
64 leading zeroes. A trailing ipv4-style dotted-decimal set is converted
65 to hex. Pure ipv4 addresses are converted to IPv4-mapped IPv6.
66 The former operator strips leading zeroes and collapses the longest
67 set of 0-groups to a double-colon.
69 5. New "-bP config" support, to dump the effective configuration.
71 6. New $dkim_key_length variable.
73 7. New base64d and base64 expansion items (the existing str2b64 being a
74 synonym of the latter). Add support in base64 for certificates.
76 8. New main configuration option "bounce_return_linesize_limit" to
77 avoid oversize bodies in bounces. The dafault value matches RFC
80 9. New $initial_cwd expansion variable.
86 1. Support for using the system standard CA bundle.
88 2. New expansion items $config_file, $config_dir, containing the file
89 and directory name of the main configuration file. Also $exim_version.
91 3. New "malware=" support for Avast.
93 4. New "spam=" variant option for Rspamd.
95 5. Assorted options on malware= and spam= scanners.
97 6. A commandline option to write a comment into the logfile.
99 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
100 be configured to make connections via socks5 proxies.
102 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
103 the transmission of UTF-8 envelope addresses.
105 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
106 used encoding of Maildir folder names.
108 10. A logging option for slow DNS lookups.
110 11. New ${env {<variable>}} expansion.
112 12. A non-SMTP authenticator using information from TLS client certificates.
114 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
115 Patch originally by Wolfgang Breyha.
117 14. Main option "dns_trust_aa" for trusting your local nameserver at the
118 same level as DNSSEC.
124 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
125 DANE smtp draft to assess a secure chain of trust of the certificate
126 used to establish the TLS connection based on a TLSA record in the
127 domain of the sender.
129 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
130 and several new events have been created. The reason is because it has
131 been expanded beyond just firing events during the transport phase. Any
132 existing TPDA transport options will have to be rewritten to use a new
133 $event_name expansion variable in a condition. Refer to the
134 experimental-spec.txt for details and examples.
136 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
137 server certs used for TLS match the result of the MX lookup. It does
138 not use the same mechanism as DANE.
148 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
149 configured to expect an initial header from a proxy that will make the
150 actual external source IP:host be used in exim instead of the IP of the
151 proxy that is connecting to it.
153 2. New verify option header_names_ascii, which will check to make sure
154 there are no non-ASCII characters in header names. Exim itself handles
155 those non-ASCII characters, but downstream apps may not, so Exim can
156 detect and reject if those characters are present.
158 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
159 codepoints with valid ones.
161 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
162 command line and matching a regex against the return data for trigger
163 and a second regex to extract malware_name. The mail spoolfile name can
164 be included in the command line.
166 5. The smtp transport now supports options "tls_verify_hosts" and
167 "tls_try_verify_hosts". If either is set the certificate verification
168 is split from the encryption operation. The default remains that a failed
169 verification cancels the encryption.
171 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
172 lookup can now set a list of servers to use that is different from the
175 7. New command-line option -C for exiqgrep to specify alternate exim.conf
176 file when searching the queue.
178 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
180 9. Support for DNSSEC on outbound connections.
182 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
183 "certextract" to extract fields from them. Hash operators md5 and sha1
184 work over them for generating fingerprints, and a new sha256 operator
187 11. PRDR is now supported dy default.
189 12. OCSP stapling is now supported by default.
191 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
192 Delivery Status Notification messages in MIME format, and negociate
193 DSN features per RFC 3461.
199 1. New command-line option -bI:sieve will list all supported sieve extensions
200 of this Exim build on standard output, one per line.
201 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
202 query this to establish the correct list to include in the protocol's
203 SIEVE capability line.
205 2. If the -n option is combined with the -bP option, then the name of an
206 emitted option is not output, only the value (if visible to you).
207 For instance, "exim -n -bP pid_file_path" should just emit a pathname
208 followed by a newline, and no other text.
210 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
211 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
212 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
213 acceptable for security. (Option accepted but ignored if using OpenSSL).
214 Defaults to 1024, the old value. May be lowered only to 512, or raised as
215 far as you like. Raising this may hinder TLS interoperability with other
216 sites and is not currently recommended. Lowering this will permit you to
217 establish a TLS session which is not as secure as you might like.
219 Unless you really know what you are doing, leave it alone.
221 4. If not built with DISABLE_DNSSEC, Exim now has the main option
222 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
223 to send the DO flag to your recursive resolver. If you have a recursive
224 resolver, which can set the Authenticated Data (AD) flag in results, Exim
225 can now detect this. Exim does not perform validation itself, instead
226 relying upon a trusted path to the resolver.
228 Current status: work-in-progress; $sender_host_dnssec variable added.
230 5. DSCP support for outbound connections: on a transport using the smtp driver,
231 set "dscp = ef", for instance, to cause the connections to have the relevant
232 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
234 Similarly for inbound connections, there is a new control modifier, dscp,
235 so "warn control = dscp/ef" in the connect ACL, or after authentication.
237 Supported values depend upon system libraries. "exim -bI:dscp" to list the
238 ones Exim knows of. You can also set a raw number 0..0x3F.
240 6. The -G command-line flag is no longer ignored; it is now equivalent to an
241 ACL setting "control = suppress_local_fixups". The -L command-line flag
242 is now accepted and forces use of syslog, with the provided tag as the
243 process name. A few other flags used by Sendmail are now accepted and
246 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
247 ACL modifier; works for single-recipient mails which are recieved on and
248 deliverable via SMTP. Using the connection made for a recipient verify,
249 if requested before the verify, or a new one made for the purpose while
250 the inbound connection is still active. The bulk of the mail item is copied
251 direct from the inbound socket to the outbound (as well as the spool file).
252 When the source notifies the end of data, the data acceptance by the destination
253 is negociated before the acceptance is sent to the source. If the destination
254 does not accept the mail item, for example due to content-scanning, the item
255 is not accepted from the source and therefore there is no need to generate
256 a bounce mail. This is of benefit when providing a secondary-MX service.
257 The downside is that delays are under the control of the ultimate destination
260 The Recieved-by: header on items delivered by cutthrough is generated
261 early in reception rather than at the end; this will affect any timestamp
262 included. The log line showing delivery is recorded before that showing
263 reception; it uses a new ">>" tag instead of "=>".
265 To support the feature, verify-callout connections can now use ESMTP and TLS.
266 The usual smtp transport options are honoured, plus a (new, default everything)
267 hosts_verify_avoid_tls.
269 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
270 for specific access to the information for each connection. The old names
271 are present for now but deprecated.
273 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
275 8. New expansion operators ${listnamed:name} to get the content of a named list
276 and ${listcount:string} to count the items in a list.
278 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
279 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
280 modules. For some situations this is desirable, but we expect admin in
281 those situations to know they want the feature. More commonly, it means
282 that GUI user modules get loaded and are broken by the setuid Exim being
283 unable to access files specified in environment variables and passed
284 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
285 unless this new option is set.
287 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
288 so have also added a build option which can be used to build Exim with GnuTLS
289 but without trying to use any kind of PKCS11 support. Uncomment this in the
292 AVOID_GNUTLS_PKCS11=yes
294 10. The "acl = name" condition on an ACL now supports optional arguments.
295 New expansion item "${acl {name}{arg}...}" and expansion condition
296 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
297 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
298 Variable $acl_narg contains the number of arguments. If the ACL sets
299 a "message =" value this becomes the result of the expansion item,
300 or the value of $value for the expansion condition. If the ACL returns
301 accept the expansion condition is true; if reject, false. A defer
302 return results in a forced fail.
304 11. Routers and transports can now have multiple headers_add and headers_remove
305 option lines. The concatenated list is used.
307 12. New ACL modifier "remove_header" can remove headers before message gets
308 handled by routers/transports.
310 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
311 "aaaa" and "a" lookups is done and the full set of results returned.
313 14. New expansion variable $headers_added with content from ACL add_header
314 modifier (but not yet added to message).
316 15. New 8bitmime status logging option for received messages. Log field "M8S".
318 16. New authenticated_sender logging option, adding to log field "A".
320 17. New expansion variables $router_name and $transport_name. Useful
321 particularly for debug_print as -bt commandline option does not
322 require privilege whereas -d does.
324 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
325 proposed extension to SMTP from Eric Hall.
327 19. The pipe transport has gained the force_command option, to allow
328 decorating commands from user .forward pipe aliases with prefix
329 wrappers, for instance.
331 20. Callout connections can now AUTH; the same controls as normal delivery
334 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
335 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
336 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
337 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
338 dmarc_status. It adds new control flags dmarc_disable_verify and
339 dmarc_enable_forensic.
341 22. Add expansion variable $authenticated_fail_id, which is the username
342 provided to the authentication method which failed. It is available
343 for use in subsequent ACL processing (typically quit or notquit ACLs).
345 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
348 24. New ${hexquote:..string..} expansion operator converts non-printable
349 characters in the string to \xNN form.
351 25. Experimental TPDA (Transport Post Delivery Action) function added.
352 Patch provided by Axel Rau.
354 26. Experimental Redis lookup added. Patch provided by Warren Baker.
360 1. New authenticator driver, "gsasl". Server-only (at present).
361 This is a SASL interface, licensed under GPL, which can be found at
362 http://www.gnu.org/software/gsasl/.
363 This system does not provide sources of data for authentication, so
364 careful use needs to be made of the conditions in Exim.
366 2. New authenticator driver, "heimdal_gssapi". Server-only.
367 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
368 is no longer honoured for setuid programs by Heimdal. Use the
369 "server_keytab" option to point to the keytab.
371 3. The "pkg-config" system can now be used when building Exim to reference
372 cflags and library information for lookups and authenticators, rather
373 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
374 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
375 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
377 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
378 find the headers and libraries for PCRE.
380 4. New expansion variable $tls_bits.
382 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
383 be joined together with ASCII NUL characters to construct the key to pass
384 into the DBM library. Can be used with gsasl to access sasldb2 files as
387 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
389 Avoid release 1.0.1a if you can. Note that the default value of
390 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
391 increased susceptibility to attack. This may still have interoperability
392 implications for very old clients (see version 4.31 change 37) but
393 administrators can choose to make the trade-off themselves and restore
394 compatibility at the cost of session security.
396 7. Use of the new expansion variable $tls_sni in the main configuration option
397 tls_certificate will cause Exim to re-expand the option, if the client
398 sends the TLS Server Name Indication extension, to permit choosing a
399 different certificate; tls_privatekey will also be re-expanded. You must
400 still set these options to expand to valid files when $tls_sni is not set.
402 The SMTP Transport has gained the option tls_sni, which will set a hostname
403 for outbound TLS sessions, and set $tls_sni too.
405 A new log_selector, +tls_sni, has been added, to log received SNI values
406 for Exim as a server.
408 8. The existing "accept_8bitmime" option now defaults to true. This means
409 that Exim is deliberately not strictly RFC compliant. We're following
410 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
411 Those who disagree, or know that they are talking to mail servers that,
412 even today, are not 8-bit clean, need to turn off this option.
414 9. Exim can now be started with -bw (with an optional timeout, given as
415 -bw<timespec>). With this, stdin at startup is a socket that is
416 already listening for connections. This has a more modern name of
417 "socket activation", but forcing the activated socket to fd 0. We're
418 interested in adding more support for modern variants.
420 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
421 for numbers indicates multiplication by 1024^3.
423 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
424 gnutls_require_mac & gnutls_require_protocols are no longer supported.
425 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
426 string, documentation for which is at:
427 http://www.gnutls.org/manual/html_node/Priority-Strings.html
429 SNI support has been added to Exim's GnuTLS integration too.
431 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
432 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
434 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
435 is now available. If the contents of the file are valid, then Exim will
436 send that back in response to a TLS status request; this is OCSP Stapling.
437 Exim will not maintain the contents of the file in any way: administrators
438 are responsible for ensuring that it is up-to-date.
440 See "experimental-spec.txt" for more details.
442 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
443 identically to TXT record lookups.
445 14. New expansion variable $tod_epoch_l for higher-precision time.
447 15. New global option tls_dh_max_bits, defaulting to current value of NSS
448 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
449 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
451 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
452 Option can now be a path or an identifier for a standard prime.
453 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
454 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
457 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
458 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
459 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
465 1. New options for the ratelimit ACL condition: /count= and /unique=.
466 The /noupdate option has been replaced by a /readonly option.
468 2. The SMTP transport's protocol option may now be set to "smtps", to
469 use SSL-on-connect outbound.
471 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
472 there is a problem talking to the AV scanner, or the AV scanner running.
474 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
475 and check if the search item is a member of the list. This does not
476 support named lists, but does subject the list part to string expansion.
478 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
479 built, Exim no longer performs string expansion on the second string of
480 the match_* expansion conditions: "match_address", "match_domain",
481 "match_ip" & "match_local_part". Named lists can still be used.
487 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
488 or off in the resolver library.
494 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
495 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
496 libraries. The following global options have been added in support of
497 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
498 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
500 2. The pipe transport now takes a boolean option, "freeze_signal", default
501 false. When true, if the external delivery command exits on a signal then
502 Exim will freeze the message in the queue, instead of generating a bounce.
504 3. Log filenames may now use %M as an escape, instead of %D (still available).
505 The %M pattern expands to yyyymm, providing month-level resolution.
507 4. The $message_linecount variable is now updated for the maildir_tag option,
508 in the same way as $message_size, to reflect the real number of lines,
509 including any header additions or removals from transport.
511 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
512 Exim now selects entries randomly, to better scale in a cluster setup.
518 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
519 the flaw permitted the Exim run-time user to cause root to append to
520 arbitrary files of the attacker's choosing, with the content based
521 on content supplied by the attacker.
523 2. Exim now supports loading some lookup types at run-time, using your
524 platform's dlopen() functionality. This has limited platform support
525 and the intention is not to support every variant, it's limited to
526 dlopen(). This permits the main Exim binary to not be linked against
527 all the libraries needed for all the lookup types.
533 NOTE: this version is not guaranteed backwards-compatible, please read the
534 items below carefully
536 1. A new main configuration option, "openssl_options", is available if Exim
537 is built with SSL support provided by OpenSSL. The option allows
538 administrators to specify OpenSSL options to be used on connections;
539 typically this is to set bug compatibility features which the OpenSSL
540 developers have not enabled by default. There may be security
541 consequences for certain options, so these should not be changed
544 2. A new pipe transport option, "permit_coredumps", may help with problem
545 diagnosis in some scenarios. Note that Exim is typically installed as
546 a setuid binary, which on most OSes will inhibit coredumps by default,
547 so that safety mechanism would have to be overridden for this option to
548 be able to take effect.
550 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
551 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
552 Note that this switches Exim to use a new API ("INSTREAM") and a future
553 release of ClamAV will remove support for the old API ("STREAM").
555 The av_scanner option, when set to "clamd", now takes an optional third
556 part, "local", which causes Exim to pass a filename to ClamAV instead of
557 the file content. This is the same behaviour as when clamd is pointed at
558 a Unix-domain socket. For example:
560 av_scanner = clamd:192.0.2.3 1234:local
562 ClamAV's ExtendedDetectionInfo response format is now handled.
564 4. There is now a -bmalware option, restricted to admin users. This option
565 takes one parameter, a filename, and scans that file with Exim's
566 malware-scanning framework. This is intended purely as a debugging aid
567 to ensure that Exim's scanning is working, not to replace other tools.
568 Note that the ACL framework is not invoked, so if av_scanner references
569 ACL variables without a fallback then this will fail.
571 5. There is a new expansion operator, "reverse_ip", which will reverse IP
572 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
574 ${reverse_ip:192.0.2.4}
576 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
577 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
579 6. There is a new ACL control called "debug", to enable debug logging.
580 This allows selective logging of certain incoming transactions within
581 production environments, with some care. It takes two options, "tag"
582 and "opts"; "tag" is included in the filename of the log and "opts"
583 is used as per the -d<options> command-line option. Examples, which
584 don't all make sense in all contexts:
587 control = debug/tag=.$sender_host_address
588 control = debug/opts=+expand+acl
589 control = debug/tag=.$message_exim_id/opts=+expand
591 7. It has always been implicit in the design and the documentation that
592 "the Exim user" is not root. src/EDITME said that using root was
593 "very strongly discouraged". This is not enough to keep people from
594 shooting themselves in the foot in days when many don't configure Exim
595 themselves but via package build managers. The security consequences of
596 running various bits of network code are severe if there should be bugs in
597 them. As such, the Exim user may no longer be root. If configured
598 statically, Exim will refuse to build. If configured as ref:user then Exim
599 will exit shortly after start-up. If you must shoot yourself in the foot,
600 then henceforth you will have to maintain your own local patches to strip
603 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
604 condition logic to determine truth/failure and will fail to expand many
605 strings, bool_lax{} uses the router condition logic, where most strings
607 Note: bool{00} is false, bool_lax{00} is true.
609 9. Routers now support multiple "condition" tests.
611 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
612 Setting this allows an admin to define which entry in the tcpwrappers
613 config file will be used to control access to the daemon. This option
614 is only available when Exim is built with USE_TCP_WRAPPERS. The
615 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
618 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
619 the Exim run-time user, instead of root.
621 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
622 is forced on. This is mitigated by the new build option
623 TRUSTED_CONFIG_LIST which defines a list of configuration files which
624 are trusted; one per line. If a config file is owned by root and matches
625 a pathname in the list, then it may be invoked by the Exim build-time
626 user without Exim relinquishing root privileges.
628 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
629 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
630 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
631 include the main config. As a transition mechanism, we are temporarily
632 providing a work-around: the new build option WHITELIST_D_MACROS provides
633 a colon-separated list of macro names which may be overridden by the Exim
634 run-time user. The values of these macros are constrained to the regex
635 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
641 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
642 writable, the other to locking of MBX folders (not mbox).
644 2. MySQL stored procedures are now supported.
646 3. The dkim_domain transport option is now a list, not a single string, and
647 messages will be signed for each element in the list (discarding
650 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
651 in the presence of multiple character strings within the RR. Prior to 4.70,
652 only the first string would be returned. The dnsdb lookup now, by default,
653 preserves the pre-4.70 semantics, but also now takes an extended output
654 separator specification. The separator can be followed by a semicolon, to
655 concatenate the individual text strings together with no join character,
656 or by a comma and a second separator character, in which case the text
657 strings within a TXT record are joined on that second character.
658 Administrators are reminded that DNS provides no ordering guarantees
659 between multiple records in an RRset. For example:
661 foo.example. IN TXT "a" "b" "c"
662 foo.example. IN TXT "d" "e" "f"
664 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
665 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
666 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
672 1. Native DKIM support without an external library.
673 (Note that if no action to prevent it is taken, a straight upgrade will
674 result in DKIM verification of all signed incoming emails. See spec
675 for details on conditionally disabling)
677 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
679 3. There is now a bool{} expansion condition which maps certain strings to
680 true/false condition values (most likely of use in conjunction with the
681 and{} expansion operator).
683 4. The $spam_score, $spam_bar and $spam_report variables are now available
686 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
687 options, provided that Exim is invoked by an admin_user.
689 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
690 which increases compatibility with older clients at the cost of decreased
691 security. Don't set this unless you need to support such clients.
693 7. There is a new expansion operator, ${randint:...} which will produce a
694 "random" number less than the supplied integer. This randomness is
695 not guaranteed to be cryptographically strong, but depending upon how
696 Exim was built may be better than the most naive schemes.
698 8. Exim now explicitly ensures that SHA256 is available when linked against
701 9. The transport_filter_timeout option now applies to SMTP transports too.
707 1. Preliminary DKIM support in Experimental.
713 1. The body_linecount and body_zerocount C variables are now exported in the
716 2. When a dnslists lookup succeeds, the key that was looked up is now placed
717 in $dnslist_matched. When the key is an IP address, it is not reversed in
718 this variable (though it is, of course, in the actual lookup). In simple
721 deny dnslists = spamhaus.example
723 the key is also available in another variable (in this case,
724 $sender_host_address). In more complicated cases, however, this is not
725 true. For example, using a data lookup might generate a dnslists lookup
728 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
730 If this condition succeeds, the value in $dnslist_matched might be
731 192.168.6.7 (for example).
733 3. Authenticators now have a client_condition option. When Exim is running as
734 a client, it skips an authenticator whose client_condition expansion yields
735 "0", "no", or "false". This can be used, for example, to skip plain text
736 authenticators when the connection is not encrypted by a setting such as:
738 client_condition = ${if !eq{$tls_cipher}{}}
740 Note that the 4.67 documentation states that $tls_cipher contains the
741 cipher used for incoming messages. In fact, during SMTP delivery, it
742 contains the cipher used for the delivery. The same is true for
745 4. There is now a -Mvc <message-id> option, which outputs a copy of the
746 message to the standard output, in RFC 2822 format. The option can be used
747 only by an admin user.
749 5. There is now a /noupdate option for the ratelimit ACL condition. It
750 computes the rate and checks the limit as normal, but it does not update
751 the saved data. This means that, in relevant ACLs, it is possible to lookup
752 the existence of a specified (or auto-generated) ratelimit key without
753 incrementing the ratelimit counter for that key.
755 In order for this to be useful, another ACL entry must set the rate
756 for the same key somewhere (otherwise it will always be zero).
761 # Read the rate; if it doesn't exist or is below the maximum
763 deny ratelimit = 100 / 5m / strict / noupdate
764 log_message = RATE: $sender_rate / $sender_rate_period \
765 (max $sender_rate_limit)
767 [... some other logic and tests...]
769 warn ratelimit = 100 / 5m / strict / per_cmd
770 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
771 (max $sender_rate_limit)
772 condition = ${if le{$sender_rate}{$sender_rate_limit}}
776 6. The variable $max_received_linelength contains the number of bytes in the
777 longest line that was received as part of the message, not counting the
778 line termination character(s).
780 7. Host lists can now include +ignore_defer and +include_defer, analagous to
781 +ignore_unknown and +include_unknown. These options should be used with
782 care, probably only in non-critical host lists such as whitelists.
784 8. There's a new option called queue_only_load_latch, which defaults true.
785 If set false when queue_only_load is greater than zero, Exim re-evaluates
786 the load for each incoming message in an SMTP session. Otherwise, once one
787 message is queued, the remainder are also.
789 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
790 cases when an SMTP session ends without sending QUIT. However, when Exim
791 itself is is bad trouble, such as being unable to write to its log files,
792 this ACL is not run, because it might try to do things (such as write to
793 log files) that make the situation even worse.
795 Like the QUIT ACL, this new ACL is provided to make it possible to gather
796 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
797 modifier is forbidden in this ACL.
799 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
800 to a string that indicates the reason for the termination of the SMTP
801 connection. The possible values are:
803 acl-drop Another ACL issued a "drop" command
804 bad-commands Too many unknown or non-mail commands
805 command-timeout Timeout while reading SMTP commands
806 connection-lost The SMTP connection has been lost
807 data-timeout Timeout while reading message data
808 local-scan-error The local_scan() function crashed
809 local-scan-timeout The local_scan() function timed out
810 signal-exit SIGTERM or SIGINT
811 synchronization-error SMTP synchronization error
812 tls-failed TLS failed to start
814 In most cases when an SMTP connection is closed without having received
815 QUIT, Exim sends an SMTP response message before actually closing the
816 connection. With the exception of acl-drop, the default message can be
817 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
818 "drop" verb in another ACL, it is the message from the other ACL that is
821 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
822 servers with individual queries. This is done by starting the query with
823 "servers=x:y:z;", where each item in the list may take one of two forms:
825 (1) If it is just a host name, the appropriate global option (mysql_servers
826 or pgsql_servers) is searched for a host of the same name, and the
827 remaining parameters (database, user, password) are taken from there.
829 (2) If it contains any slashes, it is taken as a complete parameter set.
831 The list of servers is used in exactly the same was as the global list.
832 Once a connection to a server has happened and a query has been
833 successfully executed, processing of the lookup ceases.
835 This feature is intended for use in master/slave situations where updates
836 are occurring, and one wants to update a master rather than a slave. If the
837 masters are in the list for reading, you might have:
839 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
841 In an updating lookup, you could then write
843 ${lookup mysql{servers=master; UPDATE ...}
845 If, on the other hand, the master is not to be used for reading lookups:
847 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
849 you can still update the master by
851 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
853 11. The message_body_newlines option (default FALSE, for backwards
854 compatibility) can be used to control whether newlines are present in
855 $message_body and $message_body_end. If it is FALSE, they are replaced by
862 1. There is a new log selector called smtp_no_mail, which is not included in
863 the default setting. When it is set, a line is written to the main log
864 whenever an accepted SMTP connection terminates without having issued a
867 2. When an item in a dnslists list is followed by = and & and a list of IP
868 addresses, the behaviour was not clear when the lookup returned more than
869 one IP address. This has been solved by the addition of == and =& for "all"
870 rather than the default "any" matching.
872 3. Up till now, the only control over which cipher suites GnuTLS uses has been
873 for the cipher algorithms. New options have been added to allow some of the
874 other parameters to be varied.
876 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
877 set, Exim compiles a runtime option called disable_fsync.
879 5. There is a new variable called $smtp_count_at_connection_start.
881 6. There's a new control called no_pipelining.
883 7. There are two new variables called $sending_ip_address and $sending_port.
884 These are set whenever an SMTP connection to another host has been set up.
886 8. The expansion of the helo_data option in the smtp transport now happens
887 after the connection to the server has been made.
889 9. There is a new expansion operator ${rfc2047d: that decodes strings that
890 are encoded as per RFC 2047.
892 10. There is a new log selector called "pid", which causes the current process
893 id to be added to every log line, in square brackets, immediately after the
896 11. Exim has been modified so that it flushes SMTP output before implementing
897 a delay in an ACL. It also flushes the output before performing a callout,
898 as this can take a substantial time. These behaviours can be disabled by
899 obeying control = no_delay_flush or control = no_callout_flush,
900 respectively, at some earlier stage of the connection.
902 12. There are two new expansion conditions that iterate over a list. They are
903 called forany and forall.
905 13. There's a new global option called dsn_from that can be used to vary the
906 contents of From: lines in bounces and other automatically generated
907 messages ("delivery status notifications" - hence the name of the option).
909 14. The smtp transport has a new option called hosts_avoid_pipelining.
911 15. By default, exigrep does case-insensitive matches. There is now a -I option
912 that makes it case-sensitive.
914 16. A number of new features ("addresses", "map", "filter", and "reduce") have
915 been added to string expansions to make it easier to process lists of
916 items, typically addresses.
918 17. There's a new ACL modifier called "continue". It does nothing of itself,
919 and processing of the ACL always continues with the next condition or
920 modifier. It is provided so that the side effects of expanding its argument
923 18. It is now possible to use newline and other control characters (those with
924 values less than 32, plus DEL) as separators in lists.
926 19. The exigrep utility now has a -v option, which inverts the matching
929 20. The host_find_failed option in the manualroute router can now be set to
936 No new features were added to 4.66.
942 No new features were added to 4.65.
948 1. ACL variables can now be given arbitrary names, as long as they start with
949 "acl_c" or "acl_m" (for connection variables and message variables), are at
950 least six characters long, with the sixth character being either a digit or
953 2. There is a new ACL modifier called log_reject_target. It makes it possible
954 to specify which logs are used for messages about ACL rejections.
956 3. There is a new authenticator called "dovecot". This is an interface to the
957 authentication facility of the Dovecot POP/IMAP server, which can support a
958 number of authentication methods.
960 4. The variable $message_headers_raw provides a concatenation of all the
961 messages's headers without any decoding. This is in contrast to
962 $message_headers, which does RFC2047 decoding on the header contents.
964 5. In a DNS black list, if two domain names, comma-separated, are given, the
965 second is used first to do an initial check, making use of any IP value
966 restrictions that are set. If there is a match, the first domain is used,
967 without any IP value restrictions, to get the TXT record.
969 6. All authenticators now have a server_condition option.
971 7. There is a new command-line option called -Mset. It is useful only in
972 conjunction with -be (that is, when testing string expansions). It must be
973 followed by a message id; Exim loads the given message from its spool
974 before doing the expansions.
976 8. Another similar new command-line option is called -bem. It operates like
977 -be except that it must be followed by the name of a file that contains a
980 9. When an address is delayed because of a 4xx response to a RCPT command, it
981 is now the combination of sender and recipient that is delayed in
982 subsequent queue runs until its retry time is reached.
984 10. Unary negation and the bitwise logical operators and, or, xor, not, and
985 shift, have been added to the eval: and eval10: expansion items.
987 11. The variables $interface_address and $interface_port have been renamed
988 as $received_ip_address and $received_port, to make it clear that they
989 relate to message reception rather than delivery. (The old names remain
990 available for compatibility.)
992 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
993 to vary the message that is sent when an SMTP command is accepted.
999 1. There is a new Boolean option called filter_prepend_home for the redirect
1002 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
1003 start of receiving a non-SMTP message, before any of the message has been
1006 3. When an SMTP error message is specified in a "message" modifier in an ACL,
1007 or in a :fail: or :defer: message in a redirect router, Exim now checks the
1008 start of the message for an SMTP error code.
1010 4. There is a new parameter for LDAP lookups called "referrals", which takes
1011 one of the settings "follow" (the default) or "nofollow".
1013 5. Version 20070721.2 of exipick now included, offering these new options:
1015 After all other sorting options have bee processed, reverse order
1016 before displaying messages (-R is synonym).
1018 Randomize order of matching messages before displaying.
1020 Instead of displaying the matching messages, display the sum
1022 --sort <variable>[,<variable>...]
1023 Before displaying matching messages, sort the messages according to
1024 each messages value for each variable.
1026 Negate the value for every test (returns inverse output from the
1027 same criteria without --not).
1033 1. The ${readsocket expansion item now supports Internet domain sockets as well
1034 as Unix domain sockets. If the first argument begins "inet:", it must be of
1035 the form "inet:host:port". The port is mandatory; it may be a number or the
1036 name of a TCP port in /etc/services. The host may be a name, or it may be an
1037 IP address. An ip address may optionally be enclosed in square brackets.
1038 This is best for IPv6 addresses. For example:
1040 ${readsocket{inet:[::1]:1234}{<request data>}...
1042 Only a single host name may be given, but if looking it up yield more than
1043 one IP address, they are each tried in turn until a connection is made. Once
1044 a connection has been made, the behaviour is as for ${readsocket with a Unix
1047 2. If a redirect router sets up file or pipe deliveries for more than one
1048 incoming address, and the relevant transport has batch_max set greater than
1049 one, a batch delivery now occurs.
1051 3. The appendfile transport has a new option called maildirfolder_create_regex.
1052 Its value is a regular expression. For a maildir delivery, this is matched
1053 against the maildir directory; if it matches, Exim ensures that a
1054 maildirfolder file is created alongside the new, cur, and tmp directories.
1060 The documentation is up-to-date for the 4.61 release. Major new features since
1061 the 4.60 release are:
1063 . An option called disable_ipv6, to disable the use of IPv6 completely.
1065 . An increase in the number of ACL variables to 20 of each type.
1067 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
1068 $2, $3, (though those are still set) because the numeric variables get used
1069 for other things in complicated expansions.
1071 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1073 . It is possible to use setclassresources() on some BSD OS to control the
1074 resources used in pipe deliveries.
1076 . A new ACL modifier called add_header, which can be used with any verb.
1078 . More errors are detectable in retry rules.
1080 There are a number of other additions too.
1086 The documentation is up-to-date for the 4.60 release. Major new features since
1087 the 4.50 release are:
1089 . Support for SQLite.
1091 . Support for IGNOREQUOTA in LMTP.
1093 . Extensions to the "submission mode" features.
1095 . Support for Client SMTP Authorization (CSA).
1097 . Support for ratelimiting hosts and users.
1099 . New expansion items to help with the BATV "prvs" scheme.
1101 . A "match_ip" condition, that matches an IP address against a list.
1103 There are many more minor changes.
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