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. Support for using the system standard CA bundle.
14 2. New expansion items $config_file, $config_dir, containing the file
15 and directory name of the main configuration file. Also $exim_version.
17 3. New "malware=" support for Avast.
19 4. New "spam=" variant option for Rspamd.
21 5. Assorted options on malware= and spam= scanners.
23 6. A commandline option to write a comment into the logfile.
28 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
29 DANE smtp draft to assess a secure chain of trust of the certificate
30 used to establish the TLS connection based on a TLSA record in the
33 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
34 and several new events have been created. The reason is because it has
35 been expanded beyond just firing events during the transport phase. Any
36 existing TPDA transport options will have to be rewritten to use a new
37 $event_name expansion variable in a condition. Refer to the
38 experimental-spec.txt for details and examples.
40 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
41 server certs used for TLS match the result of the MX lookup. It does
42 not use the same mechanism as DANE.
52 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
53 configured to expect an initial header from a proxy that will make the
54 actual external source IP:host be used in exim instead of the IP of the
55 proxy that is connecting to it.
57 2. New verify option header_names_ascii, which will check to make sure
58 there are no non-ASCII characters in header names. Exim itself handles
59 those non-ASCII characters, but downstream apps may not, so Exim can
60 detect and reject if those characters are present.
62 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
63 codepoints with valid ones.
65 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
66 command line and matching a regex against the return data for trigger
67 and a second regex to extract malware_name. The mail spoolfile name can
68 be included in the command line.
70 5. The smtp transport now supports options "tls_verify_hosts" and
71 "tls_try_verify_hosts". If either is set the certificate verification
72 is split from the encryption operation. The default remains that a failed
73 verification cancels the encryption.
75 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
76 lookup can now set a list of servers to use that is different from the
79 7. New command-line option -C for exiqgrep to specify alternate exim.conf
80 file when searching the queue.
82 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
84 9. Support for DNSSEC on outbound connections.
86 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
87 "certextract" to extract fields from them. Hash operators md5 and sha1
88 work over them for generating fingerprints, and a new sha256 operator
91 11. PRDR is now supported dy default.
93 12. OCSP stapling is now supported by default.
95 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
96 Delivery Status Notification messages in MIME format, and negociate
97 DSN features per RFC 3461.
103 1. New command-line option -bI:sieve will list all supported sieve extensions
104 of this Exim build on standard output, one per line.
105 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
106 query this to establish the correct list to include in the protocol's
107 SIEVE capability line.
109 2. If the -n option is combined with the -bP option, then the name of an
110 emitted option is not output, only the value (if visible to you).
111 For instance, "exim -n -bP pid_file_path" should just emit a pathname
112 followed by a newline, and no other text.
114 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
115 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
116 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
117 acceptable for security. (Option accepted but ignored if using OpenSSL).
118 Defaults to 1024, the old value. May be lowered only to 512, or raised as
119 far as you like. Raising this may hinder TLS interoperability with other
120 sites and is not currently recommended. Lowering this will permit you to
121 establish a TLS session which is not as secure as you might like.
123 Unless you really know what you are doing, leave it alone.
125 4. If not built with DISABLE_DNSSEC, Exim now has the main option
126 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
127 to send the DO flag to your recursive resolver. If you have a recursive
128 resolver, which can set the Authenticated Data (AD) flag in results, Exim
129 can now detect this. Exim does not perform validation itself, instead
130 relying upon a trusted path to the resolver.
132 Current status: work-in-progress; $sender_host_dnssec variable added.
134 5. DSCP support for outbound connections: on a transport using the smtp driver,
135 set "dscp = ef", for instance, to cause the connections to have the relevant
136 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
138 Similarly for inbound connections, there is a new control modifier, dscp,
139 so "warn control = dscp/ef" in the connect ACL, or after authentication.
141 Supported values depend upon system libraries. "exim -bI:dscp" to list the
142 ones Exim knows of. You can also set a raw number 0..0x3F.
144 6. The -G command-line flag is no longer ignored; it is now equivalent to an
145 ACL setting "control = suppress_local_fixups". The -L command-line flag
146 is now accepted and forces use of syslog, with the provided tag as the
147 process name. A few other flags used by Sendmail are now accepted and
150 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
151 ACL modifier; works for single-recipient mails which are recieved on and
152 deliverable via SMTP. Using the connection made for a recipient verify,
153 if requested before the verify, or a new one made for the purpose while
154 the inbound connection is still active. The bulk of the mail item is copied
155 direct from the inbound socket to the outbound (as well as the spool file).
156 When the source notifies the end of data, the data acceptance by the destination
157 is negociated before the acceptance is sent to the source. If the destination
158 does not accept the mail item, for example due to content-scanning, the item
159 is not accepted from the source and therefore there is no need to generate
160 a bounce mail. This is of benefit when providing a secondary-MX service.
161 The downside is that delays are under the control of the ultimate destination
164 The Recieved-by: header on items delivered by cutthrough is generated
165 early in reception rather than at the end; this will affect any timestamp
166 included. The log line showing delivery is recorded before that showing
167 reception; it uses a new ">>" tag instead of "=>".
169 To support the feature, verify-callout connections can now use ESMTP and TLS.
170 The usual smtp transport options are honoured, plus a (new, default everything)
171 hosts_verify_avoid_tls.
173 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
174 for specific access to the information for each connection. The old names
175 are present for now but deprecated.
177 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
179 8. New expansion operators ${listnamed:name} to get the content of a named list
180 and ${listcount:string} to count the items in a list.
182 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
183 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
184 modules. For some situations this is desirable, but we expect admin in
185 those situations to know they want the feature. More commonly, it means
186 that GUI user modules get loaded and are broken by the setuid Exim being
187 unable to access files specified in environment variables and passed
188 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
189 unless this new option is set.
191 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
192 so have also added a build option which can be used to build Exim with GnuTLS
193 but without trying to use any kind of PKCS11 support. Uncomment this in the
196 AVOID_GNUTLS_PKCS11=yes
198 10. The "acl = name" condition on an ACL now supports optional arguments.
199 New expansion item "${acl {name}{arg}...}" and expansion condition
200 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
201 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
202 Variable $acl_narg contains the number of arguments. If the ACL sets
203 a "message =" value this becomes the result of the expansion item,
204 or the value of $value for the expansion condition. If the ACL returns
205 accept the expansion condition is true; if reject, false. A defer
206 return results in a forced fail.
208 11. Routers and transports can now have multiple headers_add and headers_remove
209 option lines. The concatenated list is used.
211 12. New ACL modifier "remove_header" can remove headers before message gets
212 handled by routers/transports.
214 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
215 "aaaa" and "a" lookups is done and the full set of results returned.
217 14. New expansion variable $headers_added with content from ACL add_header
218 modifier (but not yet added to messsage).
220 15. New 8bitmime status logging option for received messages. Log field "M8S".
222 16. New authenticated_sender logging option, adding to log field "A".
224 17. New expansion variables $router_name and $transport_name. Useful
225 particularly for debug_print as -bt commandline option does not
226 require privilege whereas -d does.
228 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
229 proposed extension to SMTP from Eric Hall.
231 19. The pipe transport has gained the force_command option, to allow
232 decorating commands from user .forward pipe aliases with prefix
233 wrappers, for instance.
235 20. Callout connections can now AUTH; the same controls as normal delivery
238 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
239 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
240 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
241 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
242 dmarc_status. It adds new control flags dmarc_disable_verify and
243 dmarc_enable_forensic.
245 22. Add expansion variable $authenticated_fail_id, which is the username
246 provided to the authentication method which failed. It is available
247 for use in subsequent ACL processing (typically quit or notquit ACLs).
249 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
252 24. New ${hexquote:..string..} expansion operator converts non-printable
253 characters in the string to \xNN form.
255 25. Experimental TPDA (Transport Post Delivery Action) function added.
256 Patch provided by Axel Rau.
258 26. Experimental Redis lookup added. Patch provided by Warren Baker.
264 1. New authenticator driver, "gsasl". Server-only (at present).
265 This is a SASL interface, licensed under GPL, which can be found at
266 http://www.gnu.org/software/gsasl/.
267 This system does not provide sources of data for authentication, so
268 careful use needs to be made of the conditions in Exim.
270 2. New authenticator driver, "heimdal_gssapi". Server-only.
271 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
272 is no longer honoured for setuid programs by Heimdal. Use the
273 "server_keytab" option to point to the keytab.
275 3. The "pkg-config" system can now be used when building Exim to reference
276 cflags and library information for lookups and authenticators, rather
277 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
278 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
279 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
281 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
282 find the headers and libraries for PCRE.
284 4. New expansion variable $tls_bits.
286 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
287 be joined together with ASCII NUL characters to construct the key to pass
288 into the DBM library. Can be used with gsasl to access sasldb2 files as
291 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
293 Avoid release 1.0.1a if you can. Note that the default value of
294 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
295 increased susceptibility to attack. This may still have interoperability
296 implications for very old clients (see version 4.31 change 37) but
297 administrators can choose to make the trade-off themselves and restore
298 compatibility at the cost of session security.
300 7. Use of the new expansion variable $tls_sni in the main configuration option
301 tls_certificate will cause Exim to re-expand the option, if the client
302 sends the TLS Server Name Indication extension, to permit choosing a
303 different certificate; tls_privatekey will also be re-expanded. You must
304 still set these options to expand to valid files when $tls_sni is not set.
306 The SMTP Transport has gained the option tls_sni, which will set a hostname
307 for outbound TLS sessions, and set $tls_sni too.
309 A new log_selector, +tls_sni, has been added, to log received SNI values
310 for Exim as a server.
312 8. The existing "accept_8bitmime" option now defaults to true. This means
313 that Exim is deliberately not strictly RFC compliant. We're following
314 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
315 Those who disagree, or know that they are talking to mail servers that,
316 even today, are not 8-bit clean, need to turn off this option.
318 9. Exim can now be started with -bw (with an optional timeout, given as
319 -bw<timespec>). With this, stdin at startup is a socket that is
320 already listening for connections. This has a more modern name of
321 "socket activation", but forcing the activated socket to fd 0. We're
322 interested in adding more support for modern variants.
324 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
325 for numbers indicates multiplication by 1024^3.
327 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
328 gnutls_require_mac & gnutls_require_protocols are no longer supported.
329 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
330 string, documentation for which is at:
331 http://www.gnutls.org/manual/html_node/Priority-Strings.html
333 SNI support has been added to Exim's GnuTLS integration too.
335 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
336 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
338 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
339 is now available. If the contents of the file are valid, then Exim will
340 send that back in response to a TLS status request; this is OCSP Stapling.
341 Exim will not maintain the contents of the file in any way: administrators
342 are responsible for ensuring that it is up-to-date.
344 See "experimental-spec.txt" for more details.
346 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
347 identically to TXT record lookups.
349 14. New expansion variable $tod_epoch_l for higher-precision time.
351 15. New global option tls_dh_max_bits, defaulting to current value of NSS
352 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
353 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
355 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
356 Option can now be a path or an identifier for a standard prime.
357 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
358 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
361 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
362 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
363 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
369 1. New options for the ratelimit ACL condition: /count= and /unique=.
370 The /noupdate option has been replaced by a /readonly option.
372 2. The SMTP transport's protocol option may now be set to "smtps", to
373 use SSL-on-connect outbound.
375 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
376 there is a problem talking to the AV scanner, or the AV scanner running.
378 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
379 and check if the search item is a member of the list. This does not
380 support named lists, but does subject the list part to string expansion.
382 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
383 built, Exim no longer performs string expansion on the second string of
384 the match_* expansion conditions: "match_address", "match_domain",
385 "match_ip" & "match_local_part". Named lists can still be used.
391 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
392 or off in the resolver library.
398 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
399 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
400 libraries. The following global options have been added in support of
401 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
402 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
404 2. The pipe transport now takes a boolean option, "freeze_signal", default
405 false. When true, if the external delivery command exits on a signal then
406 Exim will freeze the message in the queue, instead of generating a bounce.
408 3. Log filenames may now use %M as an escape, instead of %D (still available).
409 The %M pattern expands to yyyymm, providing month-level resolution.
411 4. The $message_linecount variable is now updated for the maildir_tag option,
412 in the same way as $message_size, to reflect the real number of lines,
413 including any header additions or removals from transport.
415 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
416 Exim now selects entries randomly, to better scale in a cluster setup.
422 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
423 the flaw permitted the Exim run-time user to cause root to append to
424 arbitrary files of the attacker's choosing, with the content based
425 on content supplied by the attacker.
427 2. Exim now supports loading some lookup types at run-time, using your
428 platform's dlopen() functionality. This has limited platform support
429 and the intention is not to support every variant, it's limited to
430 dlopen(). This permits the main Exim binary to not be linked against
431 all the libraries needed for all the lookup types.
437 NOTE: this version is not guaranteed backwards-compatible, please read the
438 items below carefully
440 1. A new main configuration option, "openssl_options", is available if Exim
441 is built with SSL support provided by OpenSSL. The option allows
442 administrators to specify OpenSSL options to be used on connections;
443 typically this is to set bug compatibility features which the OpenSSL
444 developers have not enabled by default. There may be security
445 consequences for certain options, so these should not be changed
448 2. A new pipe transport option, "permit_coredumps", may help with problem
449 diagnosis in some scenarios. Note that Exim is typically installed as
450 a setuid binary, which on most OSes will inhibit coredumps by default,
451 so that safety mechanism would have to be overridden for this option to
452 be able to take effect.
454 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
455 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
456 Note that this switches Exim to use a new API ("INSTREAM") and a future
457 release of ClamAV will remove support for the old API ("STREAM").
459 The av_scanner option, when set to "clamd", now takes an optional third
460 part, "local", which causes Exim to pass a filename to ClamAV instead of
461 the file content. This is the same behaviour as when clamd is pointed at
462 a Unix-domain socket. For example:
464 av_scanner = clamd:192.0.2.3 1234:local
466 ClamAV's ExtendedDetectionInfo response format is now handled.
468 4. There is now a -bmalware option, restricted to admin users. This option
469 takes one parameter, a filename, and scans that file with Exim's
470 malware-scanning framework. This is intended purely as a debugging aid
471 to ensure that Exim's scanning is working, not to replace other tools.
472 Note that the ACL framework is not invoked, so if av_scanner references
473 ACL variables without a fallback then this will fail.
475 5. There is a new expansion operator, "reverse_ip", which will reverse IP
476 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
478 ${reverse_ip:192.0.2.4}
480 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
481 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
483 6. There is a new ACL control called "debug", to enable debug logging.
484 This allows selective logging of certain incoming transactions within
485 production environments, with some care. It takes two options, "tag"
486 and "opts"; "tag" is included in the filename of the log and "opts"
487 is used as per the -d<options> command-line option. Examples, which
488 don't all make sense in all contexts:
491 control = debug/tag=.$sender_host_address
492 control = debug/opts=+expand+acl
493 control = debug/tag=.$message_exim_id/opts=+expand
495 7. It has always been implicit in the design and the documentation that
496 "the Exim user" is not root. src/EDITME said that using root was
497 "very strongly discouraged". This is not enough to keep people from
498 shooting themselves in the foot in days when many don't configure Exim
499 themselves but via package build managers. The security consequences of
500 running various bits of network code are severe if there should be bugs in
501 them. As such, the Exim user may no longer be root. If configured
502 statically, Exim will refuse to build. If configured as ref:user then Exim
503 will exit shortly after start-up. If you must shoot yourself in the foot,
504 then henceforth you will have to maintain your own local patches to strip
507 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
508 condition logic to determine truth/failure and will fail to expand many
509 strings, bool_lax{} uses the router condition logic, where most strings
511 Note: bool{00} is false, bool_lax{00} is true.
513 9. Routers now support multiple "condition" tests.
515 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
516 Setting this allows an admin to define which entry in the tcpwrappers
517 config file will be used to control access to the daemon. This option
518 is only available when Exim is built with USE_TCP_WRAPPERS. The
519 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
522 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
523 the Exim run-time user, instead of root.
525 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
526 is forced on. This is mitigated by the new build option
527 TRUSTED_CONFIG_LIST which defines a list of configuration files which
528 are trusted; one per line. If a config file is owned by root and matches
529 a pathname in the list, then it may be invoked by the Exim build-time
530 user without Exim relinquishing root privileges.
532 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
533 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
534 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
535 include the main config. As a transition mechanism, we are temporarily
536 providing a work-around: the new build option WHITELIST_D_MACROS provides
537 a colon-separated list of macro names which may be overridden by the Exim
538 run-time user. The values of these macros are constrained to the regex
539 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
545 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
546 writable, the other to locking of MBX folders (not mbox).
548 2. MySQL stored procedures are now supported.
550 3. The dkim_domain transport option is now a list, not a single string, and
551 messages will be signed for each element in the list (discarding
554 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
555 in the presence of multiple character strings within the RR. Prior to 4.70,
556 only the first string would be returned. The dnsdb lookup now, by default,
557 preserves the pre-4.70 semantics, but also now takes an extended output
558 separator specification. The separator can be followed by a semicolon, to
559 concatenate the individual text strings together with no join character,
560 or by a comma and a second separator character, in which case the text
561 strings within a TXT record are joined on that second character.
562 Administrators are reminded that DNS provides no ordering guarantees
563 between multiple records in an RRset. For example:
565 foo.example. IN TXT "a" "b" "c"
566 foo.example. IN TXT "d" "e" "f"
568 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
569 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
570 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
576 1. Native DKIM support without an external library.
577 (Note that if no action to prevent it is taken, a straight upgrade will
578 result in DKIM verification of all signed incoming emails. See spec
579 for details on conditionally disabling)
581 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
583 3. There is now a bool{} expansion condition which maps certain strings to
584 true/false condition values (most likely of use in conjunction with the
585 and{} expansion operator).
587 4. The $spam_score, $spam_bar and $spam_report variables are now available
590 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
591 options, provided that Exim is invoked by an admin_user.
593 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
594 which increases compatibility with older clients at the cost of decreased
595 security. Don't set this unless you need to support such clients.
597 7. There is a new expansion operator, ${randint:...} which will produce a
598 "random" number less than the supplied integer. This randomness is
599 not guaranteed to be cryptographically strong, but depending upon how
600 Exim was built may be better than the most naive schemes.
602 8. Exim now explicitly ensures that SHA256 is available when linked against
605 9. The transport_filter_timeout option now applies to SMTP transports too.
611 1. Preliminary DKIM support in Experimental.
617 1. The body_linecount and body_zerocount C variables are now exported in the
620 2. When a dnslists lookup succeeds, the key that was looked up is now placed
621 in $dnslist_matched. When the key is an IP address, it is not reversed in
622 this variable (though it is, of course, in the actual lookup). In simple
625 deny dnslists = spamhaus.example
627 the key is also available in another variable (in this case,
628 $sender_host_address). In more complicated cases, however, this is not
629 true. For example, using a data lookup might generate a dnslists lookup
632 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
634 If this condition succeeds, the value in $dnslist_matched might be
635 192.168.6.7 (for example).
637 3. Authenticators now have a client_condition option. When Exim is running as
638 a client, it skips an authenticator whose client_condition expansion yields
639 "0", "no", or "false". This can be used, for example, to skip plain text
640 authenticators when the connection is not encrypted by a setting such as:
642 client_condition = ${if !eq{$tls_cipher}{}}
644 Note that the 4.67 documentation states that $tls_cipher contains the
645 cipher used for incoming messages. In fact, during SMTP delivery, it
646 contains the cipher used for the delivery. The same is true for
649 4. There is now a -Mvc <message-id> option, which outputs a copy of the
650 message to the standard output, in RFC 2822 format. The option can be used
651 only by an admin user.
653 5. There is now a /noupdate option for the ratelimit ACL condition. It
654 computes the rate and checks the limit as normal, but it does not update
655 the saved data. This means that, in relevant ACLs, it is possible to lookup
656 the existence of a specified (or auto-generated) ratelimit key without
657 incrementing the ratelimit counter for that key.
659 In order for this to be useful, another ACL entry must set the rate
660 for the same key somewhere (otherwise it will always be zero).
665 # Read the rate; if it doesn't exist or is below the maximum
667 deny ratelimit = 100 / 5m / strict / noupdate
668 log_message = RATE: $sender_rate / $sender_rate_period \
669 (max $sender_rate_limit)
671 [... some other logic and tests...]
673 warn ratelimit = 100 / 5m / strict / per_cmd
674 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
675 (max $sender_rate_limit)
676 condition = ${if le{$sender_rate}{$sender_rate_limit}}
680 6. The variable $max_received_linelength contains the number of bytes in the
681 longest line that was received as part of the message, not counting the
682 line termination character(s).
684 7. Host lists can now include +ignore_defer and +include_defer, analagous to
685 +ignore_unknown and +include_unknown. These options should be used with
686 care, probably only in non-critical host lists such as whitelists.
688 8. There's a new option called queue_only_load_latch, which defaults true.
689 If set false when queue_only_load is greater than zero, Exim re-evaluates
690 the load for each incoming message in an SMTP session. Otherwise, once one
691 message is queued, the remainder are also.
693 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
694 cases when an SMTP session ends without sending QUIT. However, when Exim
695 itself is is bad trouble, such as being unable to write to its log files,
696 this ACL is not run, because it might try to do things (such as write to
697 log files) that make the situation even worse.
699 Like the QUIT ACL, this new ACL is provided to make it possible to gather
700 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
701 modifier is forbidden in this ACL.
703 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
704 to a string that indicates the reason for the termination of the SMTP
705 connection. The possible values are:
707 acl-drop Another ACL issued a "drop" command
708 bad-commands Too many unknown or non-mail commands
709 command-timeout Timeout while reading SMTP commands
710 connection-lost The SMTP connection has been lost
711 data-timeout Timeout while reading message data
712 local-scan-error The local_scan() function crashed
713 local-scan-timeout The local_scan() function timed out
714 signal-exit SIGTERM or SIGINT
715 synchronization-error SMTP synchronization error
716 tls-failed TLS failed to start
718 In most cases when an SMTP connection is closed without having received
719 QUIT, Exim sends an SMTP response message before actually closing the
720 connection. With the exception of acl-drop, the default message can be
721 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
722 "drop" verb in another ACL, it is the message from the other ACL that is
725 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
726 servers with individual queries. This is done by starting the query with
727 "servers=x:y:z;", where each item in the list may take one of two forms:
729 (1) If it is just a host name, the appropriate global option (mysql_servers
730 or pgsql_servers) is searched for a host of the same name, and the
731 remaining parameters (database, user, password) are taken from there.
733 (2) If it contains any slashes, it is taken as a complete parameter set.
735 The list of servers is used in exactly the same was as the global list.
736 Once a connection to a server has happened and a query has been
737 successfully executed, processing of the lookup ceases.
739 This feature is intended for use in master/slave situations where updates
740 are occurring, and one wants to update a master rather than a slave. If the
741 masters are in the list for reading, you might have:
743 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
745 In an updating lookup, you could then write
747 ${lookup mysql{servers=master; UPDATE ...}
749 If, on the other hand, the master is not to be used for reading lookups:
751 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
753 you can still update the master by
755 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
757 11. The message_body_newlines option (default FALSE, for backwards
758 compatibility) can be used to control whether newlines are present in
759 $message_body and $message_body_end. If it is FALSE, they are replaced by
766 1. There is a new log selector called smtp_no_mail, which is not included in
767 the default setting. When it is set, a line is written to the main log
768 whenever an accepted SMTP connection terminates without having issued a
771 2. When an item in a dnslists list is followed by = and & and a list of IP
772 addresses, the behaviour was not clear when the lookup returned more than
773 one IP address. This has been solved by the addition of == and =& for "all"
774 rather than the default "any" matching.
776 3. Up till now, the only control over which cipher suites GnuTLS uses has been
777 for the cipher algorithms. New options have been added to allow some of the
778 other parameters to be varied.
780 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
781 set, Exim compiles a runtime option called disable_fsync.
783 5. There is a new variable called $smtp_count_at_connection_start.
785 6. There's a new control called no_pipelining.
787 7. There are two new variables called $sending_ip_address and $sending_port.
788 These are set whenever an SMTP connection to another host has been set up.
790 8. The expansion of the helo_data option in the smtp transport now happens
791 after the connection to the server has been made.
793 9. There is a new expansion operator ${rfc2047d: that decodes strings that
794 are encoded as per RFC 2047.
796 10. There is a new log selector called "pid", which causes the current process
797 id to be added to every log line, in square brackets, immediately after the
800 11. Exim has been modified so that it flushes SMTP output before implementing
801 a delay in an ACL. It also flushes the output before performing a callout,
802 as this can take a substantial time. These behaviours can be disabled by
803 obeying control = no_delay_flush or control = no_callout_flush,
804 respectively, at some earlier stage of the connection.
806 12. There are two new expansion conditions that iterate over a list. They are
807 called forany and forall.
809 13. There's a new global option called dsn_from that can be used to vary the
810 contents of From: lines in bounces and other automatically generated
811 messages ("delivery status notifications" - hence the name of the option).
813 14. The smtp transport has a new option called hosts_avoid_pipelining.
815 15. By default, exigrep does case-insensitive matches. There is now a -I option
816 that makes it case-sensitive.
818 16. A number of new features ("addresses", "map", "filter", and "reduce") have
819 been added to string expansions to make it easier to process lists of
820 items, typically addresses.
822 17. There's a new ACL modifier called "continue". It does nothing of itself,
823 and processing of the ACL always continues with the next condition or
824 modifier. It is provided so that the side effects of expanding its argument
827 18. It is now possible to use newline and other control characters (those with
828 values less than 32, plus DEL) as separators in lists.
830 19. The exigrep utility now has a -v option, which inverts the matching
833 20. The host_find_failed option in the manualroute router can now be set to
840 No new features were added to 4.66.
846 No new features were added to 4.65.
852 1. ACL variables can now be given arbitrary names, as long as they start with
853 "acl_c" or "acl_m" (for connection variables and message variables), are at
854 least six characters long, with the sixth character being either a digit or
857 2. There is a new ACL modifier called log_reject_target. It makes it possible
858 to specify which logs are used for messages about ACL rejections.
860 3. There is a new authenticator called "dovecot". This is an interface to the
861 authentication facility of the Dovecot POP/IMAP server, which can support a
862 number of authentication methods.
864 4. The variable $message_headers_raw provides a concatenation of all the
865 messages's headers without any decoding. This is in contrast to
866 $message_headers, which does RFC2047 decoding on the header contents.
868 5. In a DNS black list, if two domain names, comma-separated, are given, the
869 second is used first to do an initial check, making use of any IP value
870 restrictions that are set. If there is a match, the first domain is used,
871 without any IP value restrictions, to get the TXT record.
873 6. All authenticators now have a server_condition option.
875 7. There is a new command-line option called -Mset. It is useful only in
876 conjunction with -be (that is, when testing string expansions). It must be
877 followed by a message id; Exim loads the given message from its spool
878 before doing the expansions.
880 8. Another similar new command-line option is called -bem. It operates like
881 -be except that it must be followed by the name of a file that contains a
884 9. When an address is delayed because of a 4xx response to a RCPT command, it
885 is now the combination of sender and recipient that is delayed in
886 subsequent queue runs until its retry time is reached.
888 10. Unary negation and the bitwise logical operators and, or, xor, not, and
889 shift, have been added to the eval: and eval10: expansion items.
891 11. The variables $interface_address and $interface_port have been renamed
892 as $received_ip_address and $received_port, to make it clear that they
893 relate to message reception rather than delivery. (The old names remain
894 available for compatibility.)
896 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
897 to vary the message that is sent when an SMTP command is accepted.
903 1. There is a new Boolean option called filter_prepend_home for the redirect
906 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
907 start of receiving a non-SMTP message, before any of the message has been
910 3. When an SMTP error message is specified in a "message" modifier in an ACL,
911 or in a :fail: or :defer: message in a redirect router, Exim now checks the
912 start of the message for an SMTP error code.
914 4. There is a new parameter for LDAP lookups called "referrals", which takes
915 one of the settings "follow" (the default) or "nofollow".
917 5. Version 20070721.2 of exipick now included, offering these new options:
919 After all other sorting options have bee processed, reverse order
920 before displaying messages (-R is synonym).
922 Randomize order of matching messages before displaying.
924 Instead of displaying the matching messages, display the sum
926 --sort <variable>[,<variable>...]
927 Before displaying matching messages, sort the messages according to
928 each messages value for each variable.
930 Negate the value for every test (returns inverse output from the
931 same criteria without --not).
937 1. The ${readsocket expansion item now supports Internet domain sockets as well
938 as Unix domain sockets. If the first argument begins "inet:", it must be of
939 the form "inet:host:port". The port is mandatory; it may be a number or the
940 name of a TCP port in /etc/services. The host may be a name, or it may be an
941 IP address. An ip address may optionally be enclosed in square brackets.
942 This is best for IPv6 addresses. For example:
944 ${readsocket{inet:[::1]:1234}{<request data>}...
946 Only a single host name may be given, but if looking it up yield more than
947 one IP address, they are each tried in turn until a connection is made. Once
948 a connection has been made, the behaviour is as for ${readsocket with a Unix
951 2. If a redirect router sets up file or pipe deliveries for more than one
952 incoming address, and the relevant transport has batch_max set greater than
953 one, a batch delivery now occurs.
955 3. The appendfile transport has a new option called maildirfolder_create_regex.
956 Its value is a regular expression. For a maildir delivery, this is matched
957 against the maildir directory; if it matches, Exim ensures that a
958 maildirfolder file is created alongside the new, cur, and tmp directories.
964 The documentation is up-to-date for the 4.61 release. Major new features since
965 the 4.60 release are:
967 . An option called disable_ipv6, to disable the use of IPv6 completely.
969 . An increase in the number of ACL variables to 20 of each type.
971 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
972 $2, $3, (though those are still set) because the numeric variables get used
973 for other things in complicated expansions.
975 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
977 . It is possible to use setclassresources() on some BSD OS to control the
978 resources used in pipe deliveries.
980 . A new ACL modifier called add_header, which can be used with any verb.
982 . More errors are detectable in retry rules.
984 There are a number of other additions too.
990 The documentation is up-to-date for the 4.60 release. Major new features since
991 the 4.50 release are:
993 . Support for SQLite.
995 . Support for IGNOREQUOTA in LMTP.
997 . Extensions to the "submission mode" features.
999 . Support for Client SMTP Authorization (CSA).
1001 . Support for ratelimiting hosts and users.
1003 . New expansion items to help with the BATV "prvs" scheme.
1005 . A "match_ip" condition, that matches an IP address against a list.
1007 There are many more minor changes.
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