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.
16 1. Support for using the system standard CA bundle.
18 2. New expansion items $config_file, $config_dir, containing the file
19 and directory name of the main configuration file. Also $exim_version.
21 3. New "malware=" support for Avast.
23 4. New "spam=" variant option for Rspamd.
25 5. Assorted options on malware= and spam= scanners.
27 6. A commandline option to write a comment into the logfile.
29 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
30 be configured to make connections via socks5 proxies.
32 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
33 the transmission of UTF-8 envelope addresses.
35 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
36 used encoding of Maildir folder names.
38 10. A logging option for slow DNS lookups.
40 11. New ${env {<variable>}} expansion.
42 12. A non-SMTP authenticator using information from TLS client certificates.
44 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
45 Patch originally by Wolfgang Breyha.
47 14. Main option "dns_trust_aa" for trusting your local nameserver at the
54 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
55 DANE smtp draft to assess a secure chain of trust of the certificate
56 used to establish the TLS connection based on a TLSA record in the
59 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
60 and several new events have been created. The reason is because it has
61 been expanded beyond just firing events during the transport phase. Any
62 existing TPDA transport options will have to be rewritten to use a new
63 $event_name expansion variable in a condition. Refer to the
64 experimental-spec.txt for details and examples.
66 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
67 server certs used for TLS match the result of the MX lookup. It does
68 not use the same mechanism as DANE.
78 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
79 configured to expect an initial header from a proxy that will make the
80 actual external source IP:host be used in exim instead of the IP of the
81 proxy that is connecting to it.
83 2. New verify option header_names_ascii, which will check to make sure
84 there are no non-ASCII characters in header names. Exim itself handles
85 those non-ASCII characters, but downstream apps may not, so Exim can
86 detect and reject if those characters are present.
88 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
89 codepoints with valid ones.
91 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
92 command line and matching a regex against the return data for trigger
93 and a second regex to extract malware_name. The mail spoolfile name can
94 be included in the command line.
96 5. The smtp transport now supports options "tls_verify_hosts" and
97 "tls_try_verify_hosts". If either is set the certificate verification
98 is split from the encryption operation. The default remains that a failed
99 verification cancels the encryption.
101 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
102 lookup can now set a list of servers to use that is different from the
105 7. New command-line option -C for exiqgrep to specify alternate exim.conf
106 file when searching the queue.
108 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
110 9. Support for DNSSEC on outbound connections.
112 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
113 "certextract" to extract fields from them. Hash operators md5 and sha1
114 work over them for generating fingerprints, and a new sha256 operator
117 11. PRDR is now supported dy default.
119 12. OCSP stapling is now supported by default.
121 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
122 Delivery Status Notification messages in MIME format, and negociate
123 DSN features per RFC 3461.
129 1. New command-line option -bI:sieve will list all supported sieve extensions
130 of this Exim build on standard output, one per line.
131 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
132 query this to establish the correct list to include in the protocol's
133 SIEVE capability line.
135 2. If the -n option is combined with the -bP option, then the name of an
136 emitted option is not output, only the value (if visible to you).
137 For instance, "exim -n -bP pid_file_path" should just emit a pathname
138 followed by a newline, and no other text.
140 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
141 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
142 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
143 acceptable for security. (Option accepted but ignored if using OpenSSL).
144 Defaults to 1024, the old value. May be lowered only to 512, or raised as
145 far as you like. Raising this may hinder TLS interoperability with other
146 sites and is not currently recommended. Lowering this will permit you to
147 establish a TLS session which is not as secure as you might like.
149 Unless you really know what you are doing, leave it alone.
151 4. If not built with DISABLE_DNSSEC, Exim now has the main option
152 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
153 to send the DO flag to your recursive resolver. If you have a recursive
154 resolver, which can set the Authenticated Data (AD) flag in results, Exim
155 can now detect this. Exim does not perform validation itself, instead
156 relying upon a trusted path to the resolver.
158 Current status: work-in-progress; $sender_host_dnssec variable added.
160 5. DSCP support for outbound connections: on a transport using the smtp driver,
161 set "dscp = ef", for instance, to cause the connections to have the relevant
162 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
164 Similarly for inbound connections, there is a new control modifier, dscp,
165 so "warn control = dscp/ef" in the connect ACL, or after authentication.
167 Supported values depend upon system libraries. "exim -bI:dscp" to list the
168 ones Exim knows of. You can also set a raw number 0..0x3F.
170 6. The -G command-line flag is no longer ignored; it is now equivalent to an
171 ACL setting "control = suppress_local_fixups". The -L command-line flag
172 is now accepted and forces use of syslog, with the provided tag as the
173 process name. A few other flags used by Sendmail are now accepted and
176 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
177 ACL modifier; works for single-recipient mails which are recieved on and
178 deliverable via SMTP. Using the connection made for a recipient verify,
179 if requested before the verify, or a new one made for the purpose while
180 the inbound connection is still active. The bulk of the mail item is copied
181 direct from the inbound socket to the outbound (as well as the spool file).
182 When the source notifies the end of data, the data acceptance by the destination
183 is negociated before the acceptance is sent to the source. If the destination
184 does not accept the mail item, for example due to content-scanning, the item
185 is not accepted from the source and therefore there is no need to generate
186 a bounce mail. This is of benefit when providing a secondary-MX service.
187 The downside is that delays are under the control of the ultimate destination
190 The Recieved-by: header on items delivered by cutthrough is generated
191 early in reception rather than at the end; this will affect any timestamp
192 included. The log line showing delivery is recorded before that showing
193 reception; it uses a new ">>" tag instead of "=>".
195 To support the feature, verify-callout connections can now use ESMTP and TLS.
196 The usual smtp transport options are honoured, plus a (new, default everything)
197 hosts_verify_avoid_tls.
199 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
200 for specific access to the information for each connection. The old names
201 are present for now but deprecated.
203 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
205 8. New expansion operators ${listnamed:name} to get the content of a named list
206 and ${listcount:string} to count the items in a list.
208 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
209 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
210 modules. For some situations this is desirable, but we expect admin in
211 those situations to know they want the feature. More commonly, it means
212 that GUI user modules get loaded and are broken by the setuid Exim being
213 unable to access files specified in environment variables and passed
214 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
215 unless this new option is set.
217 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
218 so have also added a build option which can be used to build Exim with GnuTLS
219 but without trying to use any kind of PKCS11 support. Uncomment this in the
222 AVOID_GNUTLS_PKCS11=yes
224 10. The "acl = name" condition on an ACL now supports optional arguments.
225 New expansion item "${acl {name}{arg}...}" and expansion condition
226 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
227 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
228 Variable $acl_narg contains the number of arguments. If the ACL sets
229 a "message =" value this becomes the result of the expansion item,
230 or the value of $value for the expansion condition. If the ACL returns
231 accept the expansion condition is true; if reject, false. A defer
232 return results in a forced fail.
234 11. Routers and transports can now have multiple headers_add and headers_remove
235 option lines. The concatenated list is used.
237 12. New ACL modifier "remove_header" can remove headers before message gets
238 handled by routers/transports.
240 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
241 "aaaa" and "a" lookups is done and the full set of results returned.
243 14. New expansion variable $headers_added with content from ACL add_header
244 modifier (but not yet added to messsage).
246 15. New 8bitmime status logging option for received messages. Log field "M8S".
248 16. New authenticated_sender logging option, adding to log field "A".
250 17. New expansion variables $router_name and $transport_name. Useful
251 particularly for debug_print as -bt commandline option does not
252 require privilege whereas -d does.
254 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
255 proposed extension to SMTP from Eric Hall.
257 19. The pipe transport has gained the force_command option, to allow
258 decorating commands from user .forward pipe aliases with prefix
259 wrappers, for instance.
261 20. Callout connections can now AUTH; the same controls as normal delivery
264 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
265 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
266 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
267 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
268 dmarc_status. It adds new control flags dmarc_disable_verify and
269 dmarc_enable_forensic.
271 22. Add expansion variable $authenticated_fail_id, which is the username
272 provided to the authentication method which failed. It is available
273 for use in subsequent ACL processing (typically quit or notquit ACLs).
275 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
278 24. New ${hexquote:..string..} expansion operator converts non-printable
279 characters in the string to \xNN form.
281 25. Experimental TPDA (Transport Post Delivery Action) function added.
282 Patch provided by Axel Rau.
284 26. Experimental Redis lookup added. Patch provided by Warren Baker.
290 1. New authenticator driver, "gsasl". Server-only (at present).
291 This is a SASL interface, licensed under GPL, which can be found at
292 http://www.gnu.org/software/gsasl/.
293 This system does not provide sources of data for authentication, so
294 careful use needs to be made of the conditions in Exim.
296 2. New authenticator driver, "heimdal_gssapi". Server-only.
297 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
298 is no longer honoured for setuid programs by Heimdal. Use the
299 "server_keytab" option to point to the keytab.
301 3. The "pkg-config" system can now be used when building Exim to reference
302 cflags and library information for lookups and authenticators, rather
303 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
304 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
305 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
307 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
308 find the headers and libraries for PCRE.
310 4. New expansion variable $tls_bits.
312 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
313 be joined together with ASCII NUL characters to construct the key to pass
314 into the DBM library. Can be used with gsasl to access sasldb2 files as
317 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
319 Avoid release 1.0.1a if you can. Note that the default value of
320 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
321 increased susceptibility to attack. This may still have interoperability
322 implications for very old clients (see version 4.31 change 37) but
323 administrators can choose to make the trade-off themselves and restore
324 compatibility at the cost of session security.
326 7. Use of the new expansion variable $tls_sni in the main configuration option
327 tls_certificate will cause Exim to re-expand the option, if the client
328 sends the TLS Server Name Indication extension, to permit choosing a
329 different certificate; tls_privatekey will also be re-expanded. You must
330 still set these options to expand to valid files when $tls_sni is not set.
332 The SMTP Transport has gained the option tls_sni, which will set a hostname
333 for outbound TLS sessions, and set $tls_sni too.
335 A new log_selector, +tls_sni, has been added, to log received SNI values
336 for Exim as a server.
338 8. The existing "accept_8bitmime" option now defaults to true. This means
339 that Exim is deliberately not strictly RFC compliant. We're following
340 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
341 Those who disagree, or know that they are talking to mail servers that,
342 even today, are not 8-bit clean, need to turn off this option.
344 9. Exim can now be started with -bw (with an optional timeout, given as
345 -bw<timespec>). With this, stdin at startup is a socket that is
346 already listening for connections. This has a more modern name of
347 "socket activation", but forcing the activated socket to fd 0. We're
348 interested in adding more support for modern variants.
350 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
351 for numbers indicates multiplication by 1024^3.
353 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
354 gnutls_require_mac & gnutls_require_protocols are no longer supported.
355 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
356 string, documentation for which is at:
357 http://www.gnutls.org/manual/html_node/Priority-Strings.html
359 SNI support has been added to Exim's GnuTLS integration too.
361 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
362 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
364 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
365 is now available. If the contents of the file are valid, then Exim will
366 send that back in response to a TLS status request; this is OCSP Stapling.
367 Exim will not maintain the contents of the file in any way: administrators
368 are responsible for ensuring that it is up-to-date.
370 See "experimental-spec.txt" for more details.
372 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
373 identically to TXT record lookups.
375 14. New expansion variable $tod_epoch_l for higher-precision time.
377 15. New global option tls_dh_max_bits, defaulting to current value of NSS
378 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
379 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
381 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
382 Option can now be a path or an identifier for a standard prime.
383 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
384 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
387 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
388 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
389 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
395 1. New options for the ratelimit ACL condition: /count= and /unique=.
396 The /noupdate option has been replaced by a /readonly option.
398 2. The SMTP transport's protocol option may now be set to "smtps", to
399 use SSL-on-connect outbound.
401 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
402 there is a problem talking to the AV scanner, or the AV scanner running.
404 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
405 and check if the search item is a member of the list. This does not
406 support named lists, but does subject the list part to string expansion.
408 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
409 built, Exim no longer performs string expansion on the second string of
410 the match_* expansion conditions: "match_address", "match_domain",
411 "match_ip" & "match_local_part". Named lists can still be used.
417 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
418 or off in the resolver library.
424 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
425 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
426 libraries. The following global options have been added in support of
427 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
428 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
430 2. The pipe transport now takes a boolean option, "freeze_signal", default
431 false. When true, if the external delivery command exits on a signal then
432 Exim will freeze the message in the queue, instead of generating a bounce.
434 3. Log filenames may now use %M as an escape, instead of %D (still available).
435 The %M pattern expands to yyyymm, providing month-level resolution.
437 4. The $message_linecount variable is now updated for the maildir_tag option,
438 in the same way as $message_size, to reflect the real number of lines,
439 including any header additions or removals from transport.
441 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
442 Exim now selects entries randomly, to better scale in a cluster setup.
448 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
449 the flaw permitted the Exim run-time user to cause root to append to
450 arbitrary files of the attacker's choosing, with the content based
451 on content supplied by the attacker.
453 2. Exim now supports loading some lookup types at run-time, using your
454 platform's dlopen() functionality. This has limited platform support
455 and the intention is not to support every variant, it's limited to
456 dlopen(). This permits the main Exim binary to not be linked against
457 all the libraries needed for all the lookup types.
463 NOTE: this version is not guaranteed backwards-compatible, please read the
464 items below carefully
466 1. A new main configuration option, "openssl_options", is available if Exim
467 is built with SSL support provided by OpenSSL. The option allows
468 administrators to specify OpenSSL options to be used on connections;
469 typically this is to set bug compatibility features which the OpenSSL
470 developers have not enabled by default. There may be security
471 consequences for certain options, so these should not be changed
474 2. A new pipe transport option, "permit_coredumps", may help with problem
475 diagnosis in some scenarios. Note that Exim is typically installed as
476 a setuid binary, which on most OSes will inhibit coredumps by default,
477 so that safety mechanism would have to be overridden for this option to
478 be able to take effect.
480 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
481 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
482 Note that this switches Exim to use a new API ("INSTREAM") and a future
483 release of ClamAV will remove support for the old API ("STREAM").
485 The av_scanner option, when set to "clamd", now takes an optional third
486 part, "local", which causes Exim to pass a filename to ClamAV instead of
487 the file content. This is the same behaviour as when clamd is pointed at
488 a Unix-domain socket. For example:
490 av_scanner = clamd:192.0.2.3 1234:local
492 ClamAV's ExtendedDetectionInfo response format is now handled.
494 4. There is now a -bmalware option, restricted to admin users. This option
495 takes one parameter, a filename, and scans that file with Exim's
496 malware-scanning framework. This is intended purely as a debugging aid
497 to ensure that Exim's scanning is working, not to replace other tools.
498 Note that the ACL framework is not invoked, so if av_scanner references
499 ACL variables without a fallback then this will fail.
501 5. There is a new expansion operator, "reverse_ip", which will reverse IP
502 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
504 ${reverse_ip:192.0.2.4}
506 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
507 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
509 6. There is a new ACL control called "debug", to enable debug logging.
510 This allows selective logging of certain incoming transactions within
511 production environments, with some care. It takes two options, "tag"
512 and "opts"; "tag" is included in the filename of the log and "opts"
513 is used as per the -d<options> command-line option. Examples, which
514 don't all make sense in all contexts:
517 control = debug/tag=.$sender_host_address
518 control = debug/opts=+expand+acl
519 control = debug/tag=.$message_exim_id/opts=+expand
521 7. It has always been implicit in the design and the documentation that
522 "the Exim user" is not root. src/EDITME said that using root was
523 "very strongly discouraged". This is not enough to keep people from
524 shooting themselves in the foot in days when many don't configure Exim
525 themselves but via package build managers. The security consequences of
526 running various bits of network code are severe if there should be bugs in
527 them. As such, the Exim user may no longer be root. If configured
528 statically, Exim will refuse to build. If configured as ref:user then Exim
529 will exit shortly after start-up. If you must shoot yourself in the foot,
530 then henceforth you will have to maintain your own local patches to strip
533 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
534 condition logic to determine truth/failure and will fail to expand many
535 strings, bool_lax{} uses the router condition logic, where most strings
537 Note: bool{00} is false, bool_lax{00} is true.
539 9. Routers now support multiple "condition" tests.
541 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
542 Setting this allows an admin to define which entry in the tcpwrappers
543 config file will be used to control access to the daemon. This option
544 is only available when Exim is built with USE_TCP_WRAPPERS. The
545 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
548 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
549 the Exim run-time user, instead of root.
551 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
552 is forced on. This is mitigated by the new build option
553 TRUSTED_CONFIG_LIST which defines a list of configuration files which
554 are trusted; one per line. If a config file is owned by root and matches
555 a pathname in the list, then it may be invoked by the Exim build-time
556 user without Exim relinquishing root privileges.
558 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
559 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
560 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
561 include the main config. As a transition mechanism, we are temporarily
562 providing a work-around: the new build option WHITELIST_D_MACROS provides
563 a colon-separated list of macro names which may be overridden by the Exim
564 run-time user. The values of these macros are constrained to the regex
565 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
571 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
572 writable, the other to locking of MBX folders (not mbox).
574 2. MySQL stored procedures are now supported.
576 3. The dkim_domain transport option is now a list, not a single string, and
577 messages will be signed for each element in the list (discarding
580 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
581 in the presence of multiple character strings within the RR. Prior to 4.70,
582 only the first string would be returned. The dnsdb lookup now, by default,
583 preserves the pre-4.70 semantics, but also now takes an extended output
584 separator specification. The separator can be followed by a semicolon, to
585 concatenate the individual text strings together with no join character,
586 or by a comma and a second separator character, in which case the text
587 strings within a TXT record are joined on that second character.
588 Administrators are reminded that DNS provides no ordering guarantees
589 between multiple records in an RRset. For example:
591 foo.example. IN TXT "a" "b" "c"
592 foo.example. IN TXT "d" "e" "f"
594 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
595 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
596 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
602 1. Native DKIM support without an external library.
603 (Note that if no action to prevent it is taken, a straight upgrade will
604 result in DKIM verification of all signed incoming emails. See spec
605 for details on conditionally disabling)
607 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
609 3. There is now a bool{} expansion condition which maps certain strings to
610 true/false condition values (most likely of use in conjunction with the
611 and{} expansion operator).
613 4. The $spam_score, $spam_bar and $spam_report variables are now available
616 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
617 options, provided that Exim is invoked by an admin_user.
619 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
620 which increases compatibility with older clients at the cost of decreased
621 security. Don't set this unless you need to support such clients.
623 7. There is a new expansion operator, ${randint:...} which will produce a
624 "random" number less than the supplied integer. This randomness is
625 not guaranteed to be cryptographically strong, but depending upon how
626 Exim was built may be better than the most naive schemes.
628 8. Exim now explicitly ensures that SHA256 is available when linked against
631 9. The transport_filter_timeout option now applies to SMTP transports too.
637 1. Preliminary DKIM support in Experimental.
643 1. The body_linecount and body_zerocount C variables are now exported in the
646 2. When a dnslists lookup succeeds, the key that was looked up is now placed
647 in $dnslist_matched. When the key is an IP address, it is not reversed in
648 this variable (though it is, of course, in the actual lookup). In simple
651 deny dnslists = spamhaus.example
653 the key is also available in another variable (in this case,
654 $sender_host_address). In more complicated cases, however, this is not
655 true. For example, using a data lookup might generate a dnslists lookup
658 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
660 If this condition succeeds, the value in $dnslist_matched might be
661 192.168.6.7 (for example).
663 3. Authenticators now have a client_condition option. When Exim is running as
664 a client, it skips an authenticator whose client_condition expansion yields
665 "0", "no", or "false". This can be used, for example, to skip plain text
666 authenticators when the connection is not encrypted by a setting such as:
668 client_condition = ${if !eq{$tls_cipher}{}}
670 Note that the 4.67 documentation states that $tls_cipher contains the
671 cipher used for incoming messages. In fact, during SMTP delivery, it
672 contains the cipher used for the delivery. The same is true for
675 4. There is now a -Mvc <message-id> option, which outputs a copy of the
676 message to the standard output, in RFC 2822 format. The option can be used
677 only by an admin user.
679 5. There is now a /noupdate option for the ratelimit ACL condition. It
680 computes the rate and checks the limit as normal, but it does not update
681 the saved data. This means that, in relevant ACLs, it is possible to lookup
682 the existence of a specified (or auto-generated) ratelimit key without
683 incrementing the ratelimit counter for that key.
685 In order for this to be useful, another ACL entry must set the rate
686 for the same key somewhere (otherwise it will always be zero).
691 # Read the rate; if it doesn't exist or is below the maximum
693 deny ratelimit = 100 / 5m / strict / noupdate
694 log_message = RATE: $sender_rate / $sender_rate_period \
695 (max $sender_rate_limit)
697 [... some other logic and tests...]
699 warn ratelimit = 100 / 5m / strict / per_cmd
700 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
701 (max $sender_rate_limit)
702 condition = ${if le{$sender_rate}{$sender_rate_limit}}
706 6. The variable $max_received_linelength contains the number of bytes in the
707 longest line that was received as part of the message, not counting the
708 line termination character(s).
710 7. Host lists can now include +ignore_defer and +include_defer, analagous to
711 +ignore_unknown and +include_unknown. These options should be used with
712 care, probably only in non-critical host lists such as whitelists.
714 8. There's a new option called queue_only_load_latch, which defaults true.
715 If set false when queue_only_load is greater than zero, Exim re-evaluates
716 the load for each incoming message in an SMTP session. Otherwise, once one
717 message is queued, the remainder are also.
719 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
720 cases when an SMTP session ends without sending QUIT. However, when Exim
721 itself is is bad trouble, such as being unable to write to its log files,
722 this ACL is not run, because it might try to do things (such as write to
723 log files) that make the situation even worse.
725 Like the QUIT ACL, this new ACL is provided to make it possible to gather
726 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
727 modifier is forbidden in this ACL.
729 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
730 to a string that indicates the reason for the termination of the SMTP
731 connection. The possible values are:
733 acl-drop Another ACL issued a "drop" command
734 bad-commands Too many unknown or non-mail commands
735 command-timeout Timeout while reading SMTP commands
736 connection-lost The SMTP connection has been lost
737 data-timeout Timeout while reading message data
738 local-scan-error The local_scan() function crashed
739 local-scan-timeout The local_scan() function timed out
740 signal-exit SIGTERM or SIGINT
741 synchronization-error SMTP synchronization error
742 tls-failed TLS failed to start
744 In most cases when an SMTP connection is closed without having received
745 QUIT, Exim sends an SMTP response message before actually closing the
746 connection. With the exception of acl-drop, the default message can be
747 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
748 "drop" verb in another ACL, it is the message from the other ACL that is
751 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
752 servers with individual queries. This is done by starting the query with
753 "servers=x:y:z;", where each item in the list may take one of two forms:
755 (1) If it is just a host name, the appropriate global option (mysql_servers
756 or pgsql_servers) is searched for a host of the same name, and the
757 remaining parameters (database, user, password) are taken from there.
759 (2) If it contains any slashes, it is taken as a complete parameter set.
761 The list of servers is used in exactly the same was as the global list.
762 Once a connection to a server has happened and a query has been
763 successfully executed, processing of the lookup ceases.
765 This feature is intended for use in master/slave situations where updates
766 are occurring, and one wants to update a master rather than a slave. If the
767 masters are in the list for reading, you might have:
769 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
771 In an updating lookup, you could then write
773 ${lookup mysql{servers=master; UPDATE ...}
775 If, on the other hand, the master is not to be used for reading lookups:
777 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
779 you can still update the master by
781 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
783 11. The message_body_newlines option (default FALSE, for backwards
784 compatibility) can be used to control whether newlines are present in
785 $message_body and $message_body_end. If it is FALSE, they are replaced by
792 1. There is a new log selector called smtp_no_mail, which is not included in
793 the default setting. When it is set, a line is written to the main log
794 whenever an accepted SMTP connection terminates without having issued a
797 2. When an item in a dnslists list is followed by = and & and a list of IP
798 addresses, the behaviour was not clear when the lookup returned more than
799 one IP address. This has been solved by the addition of == and =& for "all"
800 rather than the default "any" matching.
802 3. Up till now, the only control over which cipher suites GnuTLS uses has been
803 for the cipher algorithms. New options have been added to allow some of the
804 other parameters to be varied.
806 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
807 set, Exim compiles a runtime option called disable_fsync.
809 5. There is a new variable called $smtp_count_at_connection_start.
811 6. There's a new control called no_pipelining.
813 7. There are two new variables called $sending_ip_address and $sending_port.
814 These are set whenever an SMTP connection to another host has been set up.
816 8. The expansion of the helo_data option in the smtp transport now happens
817 after the connection to the server has been made.
819 9. There is a new expansion operator ${rfc2047d: that decodes strings that
820 are encoded as per RFC 2047.
822 10. There is a new log selector called "pid", which causes the current process
823 id to be added to every log line, in square brackets, immediately after the
826 11. Exim has been modified so that it flushes SMTP output before implementing
827 a delay in an ACL. It also flushes the output before performing a callout,
828 as this can take a substantial time. These behaviours can be disabled by
829 obeying control = no_delay_flush or control = no_callout_flush,
830 respectively, at some earlier stage of the connection.
832 12. There are two new expansion conditions that iterate over a list. They are
833 called forany and forall.
835 13. There's a new global option called dsn_from that can be used to vary the
836 contents of From: lines in bounces and other automatically generated
837 messages ("delivery status notifications" - hence the name of the option).
839 14. The smtp transport has a new option called hosts_avoid_pipelining.
841 15. By default, exigrep does case-insensitive matches. There is now a -I option
842 that makes it case-sensitive.
844 16. A number of new features ("addresses", "map", "filter", and "reduce") have
845 been added to string expansions to make it easier to process lists of
846 items, typically addresses.
848 17. There's a new ACL modifier called "continue". It does nothing of itself,
849 and processing of the ACL always continues with the next condition or
850 modifier. It is provided so that the side effects of expanding its argument
853 18. It is now possible to use newline and other control characters (those with
854 values less than 32, plus DEL) as separators in lists.
856 19. The exigrep utility now has a -v option, which inverts the matching
859 20. The host_find_failed option in the manualroute router can now be set to
866 No new features were added to 4.66.
872 No new features were added to 4.65.
878 1. ACL variables can now be given arbitrary names, as long as they start with
879 "acl_c" or "acl_m" (for connection variables and message variables), are at
880 least six characters long, with the sixth character being either a digit or
883 2. There is a new ACL modifier called log_reject_target. It makes it possible
884 to specify which logs are used for messages about ACL rejections.
886 3. There is a new authenticator called "dovecot". This is an interface to the
887 authentication facility of the Dovecot POP/IMAP server, which can support a
888 number of authentication methods.
890 4. The variable $message_headers_raw provides a concatenation of all the
891 messages's headers without any decoding. This is in contrast to
892 $message_headers, which does RFC2047 decoding on the header contents.
894 5. In a DNS black list, if two domain names, comma-separated, are given, the
895 second is used first to do an initial check, making use of any IP value
896 restrictions that are set. If there is a match, the first domain is used,
897 without any IP value restrictions, to get the TXT record.
899 6. All authenticators now have a server_condition option.
901 7. There is a new command-line option called -Mset. It is useful only in
902 conjunction with -be (that is, when testing string expansions). It must be
903 followed by a message id; Exim loads the given message from its spool
904 before doing the expansions.
906 8. Another similar new command-line option is called -bem. It operates like
907 -be except that it must be followed by the name of a file that contains a
910 9. When an address is delayed because of a 4xx response to a RCPT command, it
911 is now the combination of sender and recipient that is delayed in
912 subsequent queue runs until its retry time is reached.
914 10. Unary negation and the bitwise logical operators and, or, xor, not, and
915 shift, have been added to the eval: and eval10: expansion items.
917 11. The variables $interface_address and $interface_port have been renamed
918 as $received_ip_address and $received_port, to make it clear that they
919 relate to message reception rather than delivery. (The old names remain
920 available for compatibility.)
922 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
923 to vary the message that is sent when an SMTP command is accepted.
929 1. There is a new Boolean option called filter_prepend_home for the redirect
932 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
933 start of receiving a non-SMTP message, before any of the message has been
936 3. When an SMTP error message is specified in a "message" modifier in an ACL,
937 or in a :fail: or :defer: message in a redirect router, Exim now checks the
938 start of the message for an SMTP error code.
940 4. There is a new parameter for LDAP lookups called "referrals", which takes
941 one of the settings "follow" (the default) or "nofollow".
943 5. Version 20070721.2 of exipick now included, offering these new options:
945 After all other sorting options have bee processed, reverse order
946 before displaying messages (-R is synonym).
948 Randomize order of matching messages before displaying.
950 Instead of displaying the matching messages, display the sum
952 --sort <variable>[,<variable>...]
953 Before displaying matching messages, sort the messages according to
954 each messages value for each variable.
956 Negate the value for every test (returns inverse output from the
957 same criteria without --not).
963 1. The ${readsocket expansion item now supports Internet domain sockets as well
964 as Unix domain sockets. If the first argument begins "inet:", it must be of
965 the form "inet:host:port". The port is mandatory; it may be a number or the
966 name of a TCP port in /etc/services. The host may be a name, or it may be an
967 IP address. An ip address may optionally be enclosed in square brackets.
968 This is best for IPv6 addresses. For example:
970 ${readsocket{inet:[::1]:1234}{<request data>}...
972 Only a single host name may be given, but if looking it up yield more than
973 one IP address, they are each tried in turn until a connection is made. Once
974 a connection has been made, the behaviour is as for ${readsocket with a Unix
977 2. If a redirect router sets up file or pipe deliveries for more than one
978 incoming address, and the relevant transport has batch_max set greater than
979 one, a batch delivery now occurs.
981 3. The appendfile transport has a new option called maildirfolder_create_regex.
982 Its value is a regular expression. For a maildir delivery, this is matched
983 against the maildir directory; if it matches, Exim ensures that a
984 maildirfolder file is created alongside the new, cur, and tmp directories.
990 The documentation is up-to-date for the 4.61 release. Major new features since
991 the 4.60 release are:
993 . An option called disable_ipv6, to disable the use of IPv6 completely.
995 . An increase in the number of ACL variables to 20 of each type.
997 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
998 $2, $3, (though those are still set) because the numeric variables get used
999 for other things in complicated expansions.
1001 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1003 . It is possible to use setclassresources() on some BSD OS to control the
1004 resources used in pipe deliveries.
1006 . A new ACL modifier called add_header, which can be used with any verb.
1008 . More errors are detectable in retry rules.
1010 There are a number of other additions too.
1016 The documentation is up-to-date for the 4.60 release. Major new features since
1017 the 4.50 release are:
1019 . Support for SQLite.
1021 . Support for IGNOREQUOTA in LMTP.
1023 . Extensions to the "submission mode" features.
1025 . Support for Client SMTP Authorization (CSA).
1027 . Support for ratelimiting hosts and users.
1029 . New expansion items to help with the BATV "prvs" scheme.
1031 . A "match_ip" condition, that matches an IP address against a list.
1033 There are many more minor changes.
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