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.
25 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
26 be configured to make connections via socks5 proxies
32 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
33 DANE smtp draft to assess a secure chain of trust of the certificate
34 used to establish the TLS connection based on a TLSA record in the
37 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
38 and several new events have been created. The reason is because it has
39 been expanded beyond just firing events during the transport phase. Any
40 existing TPDA transport options will have to be rewritten to use a new
41 $event_name expansion variable in a condition. Refer to the
42 experimental-spec.txt for details and examples.
44 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
45 server certs used for TLS match the result of the MX lookup. It does
46 not use the same mechanism as DANE.
56 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
57 configured to expect an initial header from a proxy that will make the
58 actual external source IP:host be used in exim instead of the IP of the
59 proxy that is connecting to it.
61 2. New verify option header_names_ascii, which will check to make sure
62 there are no non-ASCII characters in header names. Exim itself handles
63 those non-ASCII characters, but downstream apps may not, so Exim can
64 detect and reject if those characters are present.
66 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
67 codepoints with valid ones.
69 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
70 command line and matching a regex against the return data for trigger
71 and a second regex to extract malware_name. The mail spoolfile name can
72 be included in the command line.
74 5. The smtp transport now supports options "tls_verify_hosts" and
75 "tls_try_verify_hosts". If either is set the certificate verification
76 is split from the encryption operation. The default remains that a failed
77 verification cancels the encryption.
79 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
80 lookup can now set a list of servers to use that is different from the
83 7. New command-line option -C for exiqgrep to specify alternate exim.conf
84 file when searching the queue.
86 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
88 9. Support for DNSSEC on outbound connections.
90 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
91 "certextract" to extract fields from them. Hash operators md5 and sha1
92 work over them for generating fingerprints, and a new sha256 operator
95 11. PRDR is now supported dy default.
97 12. OCSP stapling is now supported by default.
99 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
100 Delivery Status Notification messages in MIME format, and negociate
101 DSN features per RFC 3461.
107 1. New command-line option -bI:sieve will list all supported sieve extensions
108 of this Exim build on standard output, one per line.
109 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
110 query this to establish the correct list to include in the protocol's
111 SIEVE capability line.
113 2. If the -n option is combined with the -bP option, then the name of an
114 emitted option is not output, only the value (if visible to you).
115 For instance, "exim -n -bP pid_file_path" should just emit a pathname
116 followed by a newline, and no other text.
118 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
119 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
120 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
121 acceptable for security. (Option accepted but ignored if using OpenSSL).
122 Defaults to 1024, the old value. May be lowered only to 512, or raised as
123 far as you like. Raising this may hinder TLS interoperability with other
124 sites and is not currently recommended. Lowering this will permit you to
125 establish a TLS session which is not as secure as you might like.
127 Unless you really know what you are doing, leave it alone.
129 4. If not built with DISABLE_DNSSEC, Exim now has the main option
130 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
131 to send the DO flag to your recursive resolver. If you have a recursive
132 resolver, which can set the Authenticated Data (AD) flag in results, Exim
133 can now detect this. Exim does not perform validation itself, instead
134 relying upon a trusted path to the resolver.
136 Current status: work-in-progress; $sender_host_dnssec variable added.
138 5. DSCP support for outbound connections: on a transport using the smtp driver,
139 set "dscp = ef", for instance, to cause the connections to have the relevant
140 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
142 Similarly for inbound connections, there is a new control modifier, dscp,
143 so "warn control = dscp/ef" in the connect ACL, or after authentication.
145 Supported values depend upon system libraries. "exim -bI:dscp" to list the
146 ones Exim knows of. You can also set a raw number 0..0x3F.
148 6. The -G command-line flag is no longer ignored; it is now equivalent to an
149 ACL setting "control = suppress_local_fixups". The -L command-line flag
150 is now accepted and forces use of syslog, with the provided tag as the
151 process name. A few other flags used by Sendmail are now accepted and
154 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
155 ACL modifier; works for single-recipient mails which are recieved on and
156 deliverable via SMTP. Using the connection made for a recipient verify,
157 if requested before the verify, or a new one made for the purpose while
158 the inbound connection is still active. The bulk of the mail item is copied
159 direct from the inbound socket to the outbound (as well as the spool file).
160 When the source notifies the end of data, the data acceptance by the destination
161 is negociated before the acceptance is sent to the source. If the destination
162 does not accept the mail item, for example due to content-scanning, the item
163 is not accepted from the source and therefore there is no need to generate
164 a bounce mail. This is of benefit when providing a secondary-MX service.
165 The downside is that delays are under the control of the ultimate destination
168 The Recieved-by: header on items delivered by cutthrough is generated
169 early in reception rather than at the end; this will affect any timestamp
170 included. The log line showing delivery is recorded before that showing
171 reception; it uses a new ">>" tag instead of "=>".
173 To support the feature, verify-callout connections can now use ESMTP and TLS.
174 The usual smtp transport options are honoured, plus a (new, default everything)
175 hosts_verify_avoid_tls.
177 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
178 for specific access to the information for each connection. The old names
179 are present for now but deprecated.
181 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
183 8. New expansion operators ${listnamed:name} to get the content of a named list
184 and ${listcount:string} to count the items in a list.
186 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
187 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
188 modules. For some situations this is desirable, but we expect admin in
189 those situations to know they want the feature. More commonly, it means
190 that GUI user modules get loaded and are broken by the setuid Exim being
191 unable to access files specified in environment variables and passed
192 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
193 unless this new option is set.
195 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
196 so have also added a build option which can be used to build Exim with GnuTLS
197 but without trying to use any kind of PKCS11 support. Uncomment this in the
200 AVOID_GNUTLS_PKCS11=yes
202 10. The "acl = name" condition on an ACL now supports optional arguments.
203 New expansion item "${acl {name}{arg}...}" and expansion condition
204 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
205 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
206 Variable $acl_narg contains the number of arguments. If the ACL sets
207 a "message =" value this becomes the result of the expansion item,
208 or the value of $value for the expansion condition. If the ACL returns
209 accept the expansion condition is true; if reject, false. A defer
210 return results in a forced fail.
212 11. Routers and transports can now have multiple headers_add and headers_remove
213 option lines. The concatenated list is used.
215 12. New ACL modifier "remove_header" can remove headers before message gets
216 handled by routers/transports.
218 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
219 "aaaa" and "a" lookups is done and the full set of results returned.
221 14. New expansion variable $headers_added with content from ACL add_header
222 modifier (but not yet added to messsage).
224 15. New 8bitmime status logging option for received messages. Log field "M8S".
226 16. New authenticated_sender logging option, adding to log field "A".
228 17. New expansion variables $router_name and $transport_name. Useful
229 particularly for debug_print as -bt commandline option does not
230 require privilege whereas -d does.
232 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
233 proposed extension to SMTP from Eric Hall.
235 19. The pipe transport has gained the force_command option, to allow
236 decorating commands from user .forward pipe aliases with prefix
237 wrappers, for instance.
239 20. Callout connections can now AUTH; the same controls as normal delivery
242 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
243 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
244 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
245 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
246 dmarc_status. It adds new control flags dmarc_disable_verify and
247 dmarc_enable_forensic.
249 22. Add expansion variable $authenticated_fail_id, which is the username
250 provided to the authentication method which failed. It is available
251 for use in subsequent ACL processing (typically quit or notquit ACLs).
253 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
256 24. New ${hexquote:..string..} expansion operator converts non-printable
257 characters in the string to \xNN form.
259 25. Experimental TPDA (Transport Post Delivery Action) function added.
260 Patch provided by Axel Rau.
262 26. Experimental Redis lookup added. Patch provided by Warren Baker.
268 1. New authenticator driver, "gsasl". Server-only (at present).
269 This is a SASL interface, licensed under GPL, which can be found at
270 http://www.gnu.org/software/gsasl/.
271 This system does not provide sources of data for authentication, so
272 careful use needs to be made of the conditions in Exim.
274 2. New authenticator driver, "heimdal_gssapi". Server-only.
275 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
276 is no longer honoured for setuid programs by Heimdal. Use the
277 "server_keytab" option to point to the keytab.
279 3. The "pkg-config" system can now be used when building Exim to reference
280 cflags and library information for lookups and authenticators, rather
281 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
282 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
283 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
285 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
286 find the headers and libraries for PCRE.
288 4. New expansion variable $tls_bits.
290 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
291 be joined together with ASCII NUL characters to construct the key to pass
292 into the DBM library. Can be used with gsasl to access sasldb2 files as
295 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
297 Avoid release 1.0.1a if you can. Note that the default value of
298 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
299 increased susceptibility to attack. This may still have interoperability
300 implications for very old clients (see version 4.31 change 37) but
301 administrators can choose to make the trade-off themselves and restore
302 compatibility at the cost of session security.
304 7. Use of the new expansion variable $tls_sni in the main configuration option
305 tls_certificate will cause Exim to re-expand the option, if the client
306 sends the TLS Server Name Indication extension, to permit choosing a
307 different certificate; tls_privatekey will also be re-expanded. You must
308 still set these options to expand to valid files when $tls_sni is not set.
310 The SMTP Transport has gained the option tls_sni, which will set a hostname
311 for outbound TLS sessions, and set $tls_sni too.
313 A new log_selector, +tls_sni, has been added, to log received SNI values
314 for Exim as a server.
316 8. The existing "accept_8bitmime" option now defaults to true. This means
317 that Exim is deliberately not strictly RFC compliant. We're following
318 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
319 Those who disagree, or know that they are talking to mail servers that,
320 even today, are not 8-bit clean, need to turn off this option.
322 9. Exim can now be started with -bw (with an optional timeout, given as
323 -bw<timespec>). With this, stdin at startup is a socket that is
324 already listening for connections. This has a more modern name of
325 "socket activation", but forcing the activated socket to fd 0. We're
326 interested in adding more support for modern variants.
328 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
329 for numbers indicates multiplication by 1024^3.
331 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
332 gnutls_require_mac & gnutls_require_protocols are no longer supported.
333 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
334 string, documentation for which is at:
335 http://www.gnutls.org/manual/html_node/Priority-Strings.html
337 SNI support has been added to Exim's GnuTLS integration too.
339 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
340 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
342 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
343 is now available. If the contents of the file are valid, then Exim will
344 send that back in response to a TLS status request; this is OCSP Stapling.
345 Exim will not maintain the contents of the file in any way: administrators
346 are responsible for ensuring that it is up-to-date.
348 See "experimental-spec.txt" for more details.
350 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
351 identically to TXT record lookups.
353 14. New expansion variable $tod_epoch_l for higher-precision time.
355 15. New global option tls_dh_max_bits, defaulting to current value of NSS
356 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
357 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
359 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
360 Option can now be a path or an identifier for a standard prime.
361 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
362 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
365 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
366 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
367 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
373 1. New options for the ratelimit ACL condition: /count= and /unique=.
374 The /noupdate option has been replaced by a /readonly option.
376 2. The SMTP transport's protocol option may now be set to "smtps", to
377 use SSL-on-connect outbound.
379 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
380 there is a problem talking to the AV scanner, or the AV scanner running.
382 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
383 and check if the search item is a member of the list. This does not
384 support named lists, but does subject the list part to string expansion.
386 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
387 built, Exim no longer performs string expansion on the second string of
388 the match_* expansion conditions: "match_address", "match_domain",
389 "match_ip" & "match_local_part". Named lists can still be used.
395 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
396 or off in the resolver library.
402 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
403 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
404 libraries. The following global options have been added in support of
405 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
406 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
408 2. The pipe transport now takes a boolean option, "freeze_signal", default
409 false. When true, if the external delivery command exits on a signal then
410 Exim will freeze the message in the queue, instead of generating a bounce.
412 3. Log filenames may now use %M as an escape, instead of %D (still available).
413 The %M pattern expands to yyyymm, providing month-level resolution.
415 4. The $message_linecount variable is now updated for the maildir_tag option,
416 in the same way as $message_size, to reflect the real number of lines,
417 including any header additions or removals from transport.
419 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
420 Exim now selects entries randomly, to better scale in a cluster setup.
426 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
427 the flaw permitted the Exim run-time user to cause root to append to
428 arbitrary files of the attacker's choosing, with the content based
429 on content supplied by the attacker.
431 2. Exim now supports loading some lookup types at run-time, using your
432 platform's dlopen() functionality. This has limited platform support
433 and the intention is not to support every variant, it's limited to
434 dlopen(). This permits the main Exim binary to not be linked against
435 all the libraries needed for all the lookup types.
441 NOTE: this version is not guaranteed backwards-compatible, please read the
442 items below carefully
444 1. A new main configuration option, "openssl_options", is available if Exim
445 is built with SSL support provided by OpenSSL. The option allows
446 administrators to specify OpenSSL options to be used on connections;
447 typically this is to set bug compatibility features which the OpenSSL
448 developers have not enabled by default. There may be security
449 consequences for certain options, so these should not be changed
452 2. A new pipe transport option, "permit_coredumps", may help with problem
453 diagnosis in some scenarios. Note that Exim is typically installed as
454 a setuid binary, which on most OSes will inhibit coredumps by default,
455 so that safety mechanism would have to be overridden for this option to
456 be able to take effect.
458 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
459 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
460 Note that this switches Exim to use a new API ("INSTREAM") and a future
461 release of ClamAV will remove support for the old API ("STREAM").
463 The av_scanner option, when set to "clamd", now takes an optional third
464 part, "local", which causes Exim to pass a filename to ClamAV instead of
465 the file content. This is the same behaviour as when clamd is pointed at
466 a Unix-domain socket. For example:
468 av_scanner = clamd:192.0.2.3 1234:local
470 ClamAV's ExtendedDetectionInfo response format is now handled.
472 4. There is now a -bmalware option, restricted to admin users. This option
473 takes one parameter, a filename, and scans that file with Exim's
474 malware-scanning framework. This is intended purely as a debugging aid
475 to ensure that Exim's scanning is working, not to replace other tools.
476 Note that the ACL framework is not invoked, so if av_scanner references
477 ACL variables without a fallback then this will fail.
479 5. There is a new expansion operator, "reverse_ip", which will reverse IP
480 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
482 ${reverse_ip:192.0.2.4}
484 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
485 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
487 6. There is a new ACL control called "debug", to enable debug logging.
488 This allows selective logging of certain incoming transactions within
489 production environments, with some care. It takes two options, "tag"
490 and "opts"; "tag" is included in the filename of the log and "opts"
491 is used as per the -d<options> command-line option. Examples, which
492 don't all make sense in all contexts:
495 control = debug/tag=.$sender_host_address
496 control = debug/opts=+expand+acl
497 control = debug/tag=.$message_exim_id/opts=+expand
499 7. It has always been implicit in the design and the documentation that
500 "the Exim user" is not root. src/EDITME said that using root was
501 "very strongly discouraged". This is not enough to keep people from
502 shooting themselves in the foot in days when many don't configure Exim
503 themselves but via package build managers. The security consequences of
504 running various bits of network code are severe if there should be bugs in
505 them. As such, the Exim user may no longer be root. If configured
506 statically, Exim will refuse to build. If configured as ref:user then Exim
507 will exit shortly after start-up. If you must shoot yourself in the foot,
508 then henceforth you will have to maintain your own local patches to strip
511 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
512 condition logic to determine truth/failure and will fail to expand many
513 strings, bool_lax{} uses the router condition logic, where most strings
515 Note: bool{00} is false, bool_lax{00} is true.
517 9. Routers now support multiple "condition" tests.
519 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
520 Setting this allows an admin to define which entry in the tcpwrappers
521 config file will be used to control access to the daemon. This option
522 is only available when Exim is built with USE_TCP_WRAPPERS. The
523 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
526 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
527 the Exim run-time user, instead of root.
529 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
530 is forced on. This is mitigated by the new build option
531 TRUSTED_CONFIG_LIST which defines a list of configuration files which
532 are trusted; one per line. If a config file is owned by root and matches
533 a pathname in the list, then it may be invoked by the Exim build-time
534 user without Exim relinquishing root privileges.
536 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
537 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
538 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
539 include the main config. As a transition mechanism, we are temporarily
540 providing a work-around: the new build option WHITELIST_D_MACROS provides
541 a colon-separated list of macro names which may be overridden by the Exim
542 run-time user. The values of these macros are constrained to the regex
543 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
549 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
550 writable, the other to locking of MBX folders (not mbox).
552 2. MySQL stored procedures are now supported.
554 3. The dkim_domain transport option is now a list, not a single string, and
555 messages will be signed for each element in the list (discarding
558 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
559 in the presence of multiple character strings within the RR. Prior to 4.70,
560 only the first string would be returned. The dnsdb lookup now, by default,
561 preserves the pre-4.70 semantics, but also now takes an extended output
562 separator specification. The separator can be followed by a semicolon, to
563 concatenate the individual text strings together with no join character,
564 or by a comma and a second separator character, in which case the text
565 strings within a TXT record are joined on that second character.
566 Administrators are reminded that DNS provides no ordering guarantees
567 between multiple records in an RRset. For example:
569 foo.example. IN TXT "a" "b" "c"
570 foo.example. IN TXT "d" "e" "f"
572 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
573 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
574 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
580 1. Native DKIM support without an external library.
581 (Note that if no action to prevent it is taken, a straight upgrade will
582 result in DKIM verification of all signed incoming emails. See spec
583 for details on conditionally disabling)
585 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
587 3. There is now a bool{} expansion condition which maps certain strings to
588 true/false condition values (most likely of use in conjunction with the
589 and{} expansion operator).
591 4. The $spam_score, $spam_bar and $spam_report variables are now available
594 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
595 options, provided that Exim is invoked by an admin_user.
597 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
598 which increases compatibility with older clients at the cost of decreased
599 security. Don't set this unless you need to support such clients.
601 7. There is a new expansion operator, ${randint:...} which will produce a
602 "random" number less than the supplied integer. This randomness is
603 not guaranteed to be cryptographically strong, but depending upon how
604 Exim was built may be better than the most naive schemes.
606 8. Exim now explicitly ensures that SHA256 is available when linked against
609 9. The transport_filter_timeout option now applies to SMTP transports too.
615 1. Preliminary DKIM support in Experimental.
621 1. The body_linecount and body_zerocount C variables are now exported in the
624 2. When a dnslists lookup succeeds, the key that was looked up is now placed
625 in $dnslist_matched. When the key is an IP address, it is not reversed in
626 this variable (though it is, of course, in the actual lookup). In simple
629 deny dnslists = spamhaus.example
631 the key is also available in another variable (in this case,
632 $sender_host_address). In more complicated cases, however, this is not
633 true. For example, using a data lookup might generate a dnslists lookup
636 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
638 If this condition succeeds, the value in $dnslist_matched might be
639 192.168.6.7 (for example).
641 3. Authenticators now have a client_condition option. When Exim is running as
642 a client, it skips an authenticator whose client_condition expansion yields
643 "0", "no", or "false". This can be used, for example, to skip plain text
644 authenticators when the connection is not encrypted by a setting such as:
646 client_condition = ${if !eq{$tls_cipher}{}}
648 Note that the 4.67 documentation states that $tls_cipher contains the
649 cipher used for incoming messages. In fact, during SMTP delivery, it
650 contains the cipher used for the delivery. The same is true for
653 4. There is now a -Mvc <message-id> option, which outputs a copy of the
654 message to the standard output, in RFC 2822 format. The option can be used
655 only by an admin user.
657 5. There is now a /noupdate option for the ratelimit ACL condition. It
658 computes the rate and checks the limit as normal, but it does not update
659 the saved data. This means that, in relevant ACLs, it is possible to lookup
660 the existence of a specified (or auto-generated) ratelimit key without
661 incrementing the ratelimit counter for that key.
663 In order for this to be useful, another ACL entry must set the rate
664 for the same key somewhere (otherwise it will always be zero).
669 # Read the rate; if it doesn't exist or is below the maximum
671 deny ratelimit = 100 / 5m / strict / noupdate
672 log_message = RATE: $sender_rate / $sender_rate_period \
673 (max $sender_rate_limit)
675 [... some other logic and tests...]
677 warn ratelimit = 100 / 5m / strict / per_cmd
678 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
679 (max $sender_rate_limit)
680 condition = ${if le{$sender_rate}{$sender_rate_limit}}
684 6. The variable $max_received_linelength contains the number of bytes in the
685 longest line that was received as part of the message, not counting the
686 line termination character(s).
688 7. Host lists can now include +ignore_defer and +include_defer, analagous to
689 +ignore_unknown and +include_unknown. These options should be used with
690 care, probably only in non-critical host lists such as whitelists.
692 8. There's a new option called queue_only_load_latch, which defaults true.
693 If set false when queue_only_load is greater than zero, Exim re-evaluates
694 the load for each incoming message in an SMTP session. Otherwise, once one
695 message is queued, the remainder are also.
697 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
698 cases when an SMTP session ends without sending QUIT. However, when Exim
699 itself is is bad trouble, such as being unable to write to its log files,
700 this ACL is not run, because it might try to do things (such as write to
701 log files) that make the situation even worse.
703 Like the QUIT ACL, this new ACL is provided to make it possible to gather
704 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
705 modifier is forbidden in this ACL.
707 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
708 to a string that indicates the reason for the termination of the SMTP
709 connection. The possible values are:
711 acl-drop Another ACL issued a "drop" command
712 bad-commands Too many unknown or non-mail commands
713 command-timeout Timeout while reading SMTP commands
714 connection-lost The SMTP connection has been lost
715 data-timeout Timeout while reading message data
716 local-scan-error The local_scan() function crashed
717 local-scan-timeout The local_scan() function timed out
718 signal-exit SIGTERM or SIGINT
719 synchronization-error SMTP synchronization error
720 tls-failed TLS failed to start
722 In most cases when an SMTP connection is closed without having received
723 QUIT, Exim sends an SMTP response message before actually closing the
724 connection. With the exception of acl-drop, the default message can be
725 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
726 "drop" verb in another ACL, it is the message from the other ACL that is
729 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
730 servers with individual queries. This is done by starting the query with
731 "servers=x:y:z;", where each item in the list may take one of two forms:
733 (1) If it is just a host name, the appropriate global option (mysql_servers
734 or pgsql_servers) is searched for a host of the same name, and the
735 remaining parameters (database, user, password) are taken from there.
737 (2) If it contains any slashes, it is taken as a complete parameter set.
739 The list of servers is used in exactly the same was as the global list.
740 Once a connection to a server has happened and a query has been
741 successfully executed, processing of the lookup ceases.
743 This feature is intended for use in master/slave situations where updates
744 are occurring, and one wants to update a master rather than a slave. If the
745 masters are in the list for reading, you might have:
747 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
749 In an updating lookup, you could then write
751 ${lookup mysql{servers=master; UPDATE ...}
753 If, on the other hand, the master is not to be used for reading lookups:
755 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
757 you can still update the master by
759 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
761 11. The message_body_newlines option (default FALSE, for backwards
762 compatibility) can be used to control whether newlines are present in
763 $message_body and $message_body_end. If it is FALSE, they are replaced by
770 1. There is a new log selector called smtp_no_mail, which is not included in
771 the default setting. When it is set, a line is written to the main log
772 whenever an accepted SMTP connection terminates without having issued a
775 2. When an item in a dnslists list is followed by = and & and a list of IP
776 addresses, the behaviour was not clear when the lookup returned more than
777 one IP address. This has been solved by the addition of == and =& for "all"
778 rather than the default "any" matching.
780 3. Up till now, the only control over which cipher suites GnuTLS uses has been
781 for the cipher algorithms. New options have been added to allow some of the
782 other parameters to be varied.
784 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
785 set, Exim compiles a runtime option called disable_fsync.
787 5. There is a new variable called $smtp_count_at_connection_start.
789 6. There's a new control called no_pipelining.
791 7. There are two new variables called $sending_ip_address and $sending_port.
792 These are set whenever an SMTP connection to another host has been set up.
794 8. The expansion of the helo_data option in the smtp transport now happens
795 after the connection to the server has been made.
797 9. There is a new expansion operator ${rfc2047d: that decodes strings that
798 are encoded as per RFC 2047.
800 10. There is a new log selector called "pid", which causes the current process
801 id to be added to every log line, in square brackets, immediately after the
804 11. Exim has been modified so that it flushes SMTP output before implementing
805 a delay in an ACL. It also flushes the output before performing a callout,
806 as this can take a substantial time. These behaviours can be disabled by
807 obeying control = no_delay_flush or control = no_callout_flush,
808 respectively, at some earlier stage of the connection.
810 12. There are two new expansion conditions that iterate over a list. They are
811 called forany and forall.
813 13. There's a new global option called dsn_from that can be used to vary the
814 contents of From: lines in bounces and other automatically generated
815 messages ("delivery status notifications" - hence the name of the option).
817 14. The smtp transport has a new option called hosts_avoid_pipelining.
819 15. By default, exigrep does case-insensitive matches. There is now a -I option
820 that makes it case-sensitive.
822 16. A number of new features ("addresses", "map", "filter", and "reduce") have
823 been added to string expansions to make it easier to process lists of
824 items, typically addresses.
826 17. There's a new ACL modifier called "continue". It does nothing of itself,
827 and processing of the ACL always continues with the next condition or
828 modifier. It is provided so that the side effects of expanding its argument
831 18. It is now possible to use newline and other control characters (those with
832 values less than 32, plus DEL) as separators in lists.
834 19. The exigrep utility now has a -v option, which inverts the matching
837 20. The host_find_failed option in the manualroute router can now be set to
844 No new features were added to 4.66.
850 No new features were added to 4.65.
856 1. ACL variables can now be given arbitrary names, as long as they start with
857 "acl_c" or "acl_m" (for connection variables and message variables), are at
858 least six characters long, with the sixth character being either a digit or
861 2. There is a new ACL modifier called log_reject_target. It makes it possible
862 to specify which logs are used for messages about ACL rejections.
864 3. There is a new authenticator called "dovecot". This is an interface to the
865 authentication facility of the Dovecot POP/IMAP server, which can support a
866 number of authentication methods.
868 4. The variable $message_headers_raw provides a concatenation of all the
869 messages's headers without any decoding. This is in contrast to
870 $message_headers, which does RFC2047 decoding on the header contents.
872 5. In a DNS black list, if two domain names, comma-separated, are given, the
873 second is used first to do an initial check, making use of any IP value
874 restrictions that are set. If there is a match, the first domain is used,
875 without any IP value restrictions, to get the TXT record.
877 6. All authenticators now have a server_condition option.
879 7. There is a new command-line option called -Mset. It is useful only in
880 conjunction with -be (that is, when testing string expansions). It must be
881 followed by a message id; Exim loads the given message from its spool
882 before doing the expansions.
884 8. Another similar new command-line option is called -bem. It operates like
885 -be except that it must be followed by the name of a file that contains a
888 9. When an address is delayed because of a 4xx response to a RCPT command, it
889 is now the combination of sender and recipient that is delayed in
890 subsequent queue runs until its retry time is reached.
892 10. Unary negation and the bitwise logical operators and, or, xor, not, and
893 shift, have been added to the eval: and eval10: expansion items.
895 11. The variables $interface_address and $interface_port have been renamed
896 as $received_ip_address and $received_port, to make it clear that they
897 relate to message reception rather than delivery. (The old names remain
898 available for compatibility.)
900 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
901 to vary the message that is sent when an SMTP command is accepted.
907 1. There is a new Boolean option called filter_prepend_home for the redirect
910 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
911 start of receiving a non-SMTP message, before any of the message has been
914 3. When an SMTP error message is specified in a "message" modifier in an ACL,
915 or in a :fail: or :defer: message in a redirect router, Exim now checks the
916 start of the message for an SMTP error code.
918 4. There is a new parameter for LDAP lookups called "referrals", which takes
919 one of the settings "follow" (the default) or "nofollow".
921 5. Version 20070721.2 of exipick now included, offering these new options:
923 After all other sorting options have bee processed, reverse order
924 before displaying messages (-R is synonym).
926 Randomize order of matching messages before displaying.
928 Instead of displaying the matching messages, display the sum
930 --sort <variable>[,<variable>...]
931 Before displaying matching messages, sort the messages according to
932 each messages value for each variable.
934 Negate the value for every test (returns inverse output from the
935 same criteria without --not).
941 1. The ${readsocket expansion item now supports Internet domain sockets as well
942 as Unix domain sockets. If the first argument begins "inet:", it must be of
943 the form "inet:host:port". The port is mandatory; it may be a number or the
944 name of a TCP port in /etc/services. The host may be a name, or it may be an
945 IP address. An ip address may optionally be enclosed in square brackets.
946 This is best for IPv6 addresses. For example:
948 ${readsocket{inet:[::1]:1234}{<request data>}...
950 Only a single host name may be given, but if looking it up yield more than
951 one IP address, they are each tried in turn until a connection is made. Once
952 a connection has been made, the behaviour is as for ${readsocket with a Unix
955 2. If a redirect router sets up file or pipe deliveries for more than one
956 incoming address, and the relevant transport has batch_max set greater than
957 one, a batch delivery now occurs.
959 3. The appendfile transport has a new option called maildirfolder_create_regex.
960 Its value is a regular expression. For a maildir delivery, this is matched
961 against the maildir directory; if it matches, Exim ensures that a
962 maildirfolder file is created alongside the new, cur, and tmp directories.
968 The documentation is up-to-date for the 4.61 release. Major new features since
969 the 4.60 release are:
971 . An option called disable_ipv6, to disable the use of IPv6 completely.
973 . An increase in the number of ACL variables to 20 of each type.
975 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
976 $2, $3, (though those are still set) because the numeric variables get used
977 for other things in complicated expansions.
979 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
981 . It is possible to use setclassresources() on some BSD OS to control the
982 resources used in pipe deliveries.
984 . A new ACL modifier called add_header, which can be used with any verb.
986 . More errors are detectable in retry rules.
988 There are a number of other additions too.
994 The documentation is up-to-date for the 4.60 release. Major new features since
995 the 4.50 release are:
997 . Support for SQLite.
999 . Support for IGNOREQUOTA in LMTP.
1001 . Extensions to the "submission mode" features.
1003 . Support for Client SMTP Authorization (CSA).
1005 . Support for ratelimiting hosts and users.
1007 . New expansion items to help with the BATV "prvs" scheme.
1009 . A "match_ip" condition, that matches an IP address against a list.
1011 There are many more minor changes.
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