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. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
13 configured to expect an initial header from a proxy that will make the
14 actual external source IP:host be used in exim instead of the IP of the
15 proxy that is connecting to it.
17 2. New verify option header_names_ascii, which will check to make sure
18 there are no non-ASCII characters in header names. Exim itself handles
19 those non-ASCII characters, but downstream apps may not, so Exim can
20 detect and reject if those characters are present.
22 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
23 codepoints with valid ones.
25 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
26 command line and matching a regex against the return data for trigger
27 and a second regex to extract malware_name. The mail spoofile name can
28 be included in the command line.
30 5. The smtp transport now supports options "tls_verify_hosts" and
31 "tls_try_verify_hosts". If either is set the certificate verification
32 is split from the encryption operation. The default remains that a failed
33 verification cancels the encryption.
35 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
36 lookup can now set a list of servers to use that is different from the
39 7. New command-line option -C for exiqgrep to specify alternate exim.conf
40 file when searching the queue.
42 8. EXPERIMENTAL_OCSP now supports GnuTLS also, if you have version 3.1.3
45 9. Support for DNSSEC on outbound connections.
47 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
48 "certextract" to extract fields from them. Hash operators md5 and sha1
49 work over them for generating fingerprints.
55 1. New command-line option -bI:sieve will list all supported sieve extensions
56 of this Exim build on standard output, one per line.
57 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
58 query this to establish the correct list to include in the protocol's
59 SIEVE capability line.
61 2. If the -n option is combined with the -bP option, then the name of an
62 emitted option is not output, only the value (if visible to you).
63 For instance, "exim -n -bP pid_file_path" should just emit a pathname
64 followed by a newline, and no other text.
66 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
67 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
68 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
69 acceptable for security. (Option accepted but ignored if using OpenSSL).
70 Defaults to 1024, the old value. May be lowered only to 512, or raised as
71 far as you like. Raising this may hinder TLS interoperability with other
72 sites and is not currently recommended. Lowering this will permit you to
73 establish a TLS session which is not as secure as you might like.
75 Unless you really know what you are doing, leave it alone.
77 4. If not built with DISABLE_DNSSEC, Exim now has the main option
78 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
79 to send the DO flag to your recursive resolver. If you have a recursive
80 resolver, which can set the Authenticated Data (AD) flag in results, Exim
81 can now detect this. Exim does not perform validation itself, instead
82 relying upon a trusted path to the resolver.
84 Current status: work-in-progress; $sender_host_dnssec variable added.
86 5. DSCP support for outbound connections: on a transport using the smtp driver,
87 set "dscp = ef", for instance, to cause the connections to have the relevant
88 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
90 Similarly for inbound connections, there is a new control modifier, dscp,
91 so "warn control = dscp/ef" in the connect ACL, or after authentication.
93 Supported values depend upon system libraries. "exim -bI:dscp" to list the
94 ones Exim knows of. You can also set a raw number 0..0x3F.
96 6. The -G command-line flag is no longer ignored; it is now equivalent to an
97 ACL setting "control = suppress_local_fixups". The -L command-line flag
98 is now accepted and forces use of syslog, with the provided tag as the
99 process name. A few other flags used by Sendmail are now accepted and
102 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
103 ACL modifier; works for single-recipient mails which are recieved on and
104 deliverable via SMTP. Using the connection made for a recipient verify,
105 if requested before the verify, or a new one made for the purpose while
106 the inbound connection is still active. The bulk of the mail item is copied
107 direct from the inbound socket to the outbound (as well as the spool file).
108 When the source notifies the end of data, the data acceptance by the destination
109 is negociated before the acceptance is sent to the source. If the destination
110 does not accept the mail item, for example due to content-scanning, the item
111 is not accepted from the source and therefore there is no need to generate
112 a bounce mail. This is of benefit when providing a secondary-MX service.
113 The downside is that delays are under the control of the ultimate destination
116 The Recieved-by: header on items delivered by cutthrough is generated
117 early in reception rather than at the end; this will affect any timestamp
118 included. The log line showing delivery is recorded before that showing
119 reception; it uses a new ">>" tag instead of "=>".
121 To support the feature, verify-callout connections can now use ESMTP and TLS.
122 The usual smtp transport options are honoured, plus a (new, default everything)
123 hosts_verify_avoid_tls.
125 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
126 for specific access to the information for each connection. The old names
127 are present for now but deprecated.
129 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
131 8. New expansion operators ${listnamed:name} to get the content of a named list
132 and ${listcount:string} to count the items in a list.
134 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
135 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
136 modules. For some situations this is desirable, but we expect admin in
137 those situations to know they want the feature. More commonly, it means
138 that GUI user modules get loaded and are broken by the setuid Exim being
139 unable to access files specified in environment variables and passed
140 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
141 unless this new option is set.
143 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
144 so have also added a build option which can be used to build Exim with GnuTLS
145 but without trying to use any kind of PKCS11 support. Uncomment this in the
148 AVOID_GNUTLS_PKCS11=yes
150 10. The "acl = name" condition on an ACL now supports optional arguments.
151 New expansion item "${acl {name}{arg}...}" and expansion condition
152 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
153 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
154 Variable $acl_narg contains the number of arguments. If the ACL sets
155 a "message =" value this becomes the result of the expansion item,
156 or the value of $value for the expansion condition. If the ACL returns
157 accept the expansion condition is true; if reject, false. A defer
158 return results in a forced fail.
160 11. Routers and transports can now have multiple headers_add and headers_remove
161 option lines. The concatenated list is used.
163 12. New ACL modifier "remove_header" can remove headers before message gets
164 handled by routers/transports.
166 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
167 "aaaa" and "a" lookups is done and the full set of results returned.
169 14. New expansion variable $headers_added with content from ACL add_header
170 modifier (but not yet added to messsage).
172 15. New 8bitmime status logging option for received messages. Log field "M8S".
174 16. New authenticated_sender logging option, adding to log field "A".
176 17. New expansion variables $router_name and $transport_name. Useful
177 particularly for debug_print as -bt commandline option does not
178 require privilege whereas -d does.
180 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
181 proposed extension to SMTP from Eric Hall.
183 19. The pipe transport has gained the force_command option, to allow
184 decorating commands from user .forward pipe aliases with prefix
185 wrappers, for instance.
187 20. Callout connections can now AUTH; the same controls as normal delivery
190 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
191 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
192 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
193 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
194 dmarc_status. It adds new control flags dmarc_disable_verify and
195 dmarc_enable_forensic.
197 22. Add expansion variable $authenticated_fail_id, which is the username
198 provided to the authentication method which failed. It is available
199 for use in subsequent ACL processing (typically quit or notquit ACLs).
201 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
204 24. New ${hexquote:..string..} expansion operator converts non-printable
205 characters in the string to \xNN form.
207 25. Experimental TPDA (Transport Post Delivery Action) function added.
208 Patch provided by Axel Rau.
210 26. Experimental Redis lookup added. Patch provided by Warren Baker.
216 1. New authenticator driver, "gsasl". Server-only (at present).
217 This is a SASL interface, licensed under GPL, which can be found at
218 http://www.gnu.org/software/gsasl/.
219 This system does not provide sources of data for authentication, so
220 careful use needs to be made of the conditions in Exim.
222 2. New authenticator driver, "heimdal_gssapi". Server-only.
223 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
224 is no longer honoured for setuid programs by Heimdal. Use the
225 "server_keytab" option to point to the keytab.
227 3. The "pkg-config" system can now be used when building Exim to reference
228 cflags and library information for lookups and authenticators, rather
229 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
230 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
231 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
233 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
234 find the headers and libraries for PCRE.
236 4. New expansion variable $tls_bits.
238 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
239 be joined together with ASCII NUL characters to construct the key to pass
240 into the DBM library. Can be used with gsasl to access sasldb2 files as
243 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
245 Avoid release 1.0.1a if you can. Note that the default value of
246 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
247 increased susceptibility to attack. This may still have interoperability
248 implications for very old clients (see version 4.31 change 37) but
249 administrators can choose to make the trade-off themselves and restore
250 compatibility at the cost of session security.
252 7. Use of the new expansion variable $tls_sni in the main configuration option
253 tls_certificate will cause Exim to re-expand the option, if the client
254 sends the TLS Server Name Indication extension, to permit choosing a
255 different certificate; tls_privatekey will also be re-expanded. You must
256 still set these options to expand to valid files when $tls_sni is not set.
258 The SMTP Transport has gained the option tls_sni, which will set a hostname
259 for outbound TLS sessions, and set $tls_sni too.
261 A new log_selector, +tls_sni, has been added, to log received SNI values
262 for Exim as a server.
264 8. The existing "accept_8bitmime" option now defaults to true. This means
265 that Exim is deliberately not strictly RFC compliant. We're following
266 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
267 Those who disagree, or know that they are talking to mail servers that,
268 even today, are not 8-bit clean, need to turn off this option.
270 9. Exim can now be started with -bw (with an optional timeout, given as
271 -bw<timespec>). With this, stdin at startup is a socket that is
272 already listening for connections. This has a more modern name of
273 "socket activation", but forcing the activated socket to fd 0. We're
274 interested in adding more support for modern variants.
276 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
277 for numbers indicates multiplication by 1024^3.
279 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
280 gnutls_require_mac & gnutls_require_protocols are no longer supported.
281 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
282 string, documentation for which is at:
283 http://www.gnutls.org/manual/html_node/Priority-Strings.html
285 SNI support has been added to Exim's GnuTLS integration too.
287 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
288 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
290 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
291 is now available. If the contents of the file are valid, then Exim will
292 send that back in response to a TLS status request; this is OCSP Stapling.
293 Exim will not maintain the contents of the file in any way: administrators
294 are responsible for ensuring that it is up-to-date.
296 See "experimental-spec.txt" for more details.
298 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
299 identically to TXT record lookups.
301 14. New expansion variable $tod_epoch_l for higher-precision time.
303 15. New global option tls_dh_max_bits, defaulting to current value of NSS
304 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
305 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
307 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
308 Option can now be a path or an identifier for a standard prime.
309 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
310 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
313 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
314 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
315 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
321 1. New options for the ratelimit ACL condition: /count= and /unique=.
322 The /noupdate option has been replaced by a /readonly option.
324 2. The SMTP transport's protocol option may now be set to "smtps", to
325 use SSL-on-connect outbound.
327 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
328 there is a problem talking to the AV scanner, or the AV scanner running.
330 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
331 and check if the search item is a member of the list. This does not
332 support named lists, but does subject the list part to string expansion.
334 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
335 built, Exim no longer performs string expansion on the second string of
336 the match_* expansion conditions: "match_address", "match_domain",
337 "match_ip" & "match_local_part". Named lists can still be used.
343 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
344 or off in the resolver library.
350 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
351 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
352 libraries. The following global options have been added in support of
353 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
354 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
356 2. The pipe transport now takes a boolean option, "freeze_signal", default
357 false. When true, if the external delivery command exits on a signal then
358 Exim will freeze the message in the queue, instead of generating a bounce.
360 3. Log filenames may now use %M as an escape, instead of %D (still available).
361 The %M pattern expands to yyyymm, providing month-level resolution.
363 4. The $message_linecount variable is now updated for the maildir_tag option,
364 in the same way as $message_size, to reflect the real number of lines,
365 including any header additions or removals from transport.
367 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
368 Exim now selects entries randomly, to better scale in a cluster setup.
374 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
375 the flaw permitted the Exim run-time user to cause root to append to
376 arbitrary files of the attacker's choosing, with the content based
377 on content supplied by the attacker.
379 2. Exim now supports loading some lookup types at run-time, using your
380 platform's dlopen() functionality. This has limited platform support
381 and the intention is not to support every variant, it's limited to
382 dlopen(). This permits the main Exim binary to not be linked against
383 all the libraries needed for all the lookup types.
389 NOTE: this version is not guaranteed backwards-compatible, please read the
390 items below carefully
392 1. A new main configuration option, "openssl_options", is available if Exim
393 is built with SSL support provided by OpenSSL. The option allows
394 administrators to specify OpenSSL options to be used on connections;
395 typically this is to set bug compatibility features which the OpenSSL
396 developers have not enabled by default. There may be security
397 consequences for certain options, so these should not be changed
400 2. A new pipe transport option, "permit_coredumps", may help with problem
401 diagnosis in some scenarios. Note that Exim is typically installed as
402 a setuid binary, which on most OSes will inhibit coredumps by default,
403 so that safety mechanism would have to be overridden for this option to
404 be able to take effect.
406 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
407 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
408 Note that this switches Exim to use a new API ("INSTREAM") and a future
409 release of ClamAV will remove support for the old API ("STREAM").
411 The av_scanner option, when set to "clamd", now takes an optional third
412 part, "local", which causes Exim to pass a filename to ClamAV instead of
413 the file content. This is the same behaviour as when clamd is pointed at
414 a Unix-domain socket. For example:
416 av_scanner = clamd:192.0.2.3 1234:local
418 ClamAV's ExtendedDetectionInfo response format is now handled.
420 4. There is now a -bmalware option, restricted to admin users. This option
421 takes one parameter, a filename, and scans that file with Exim's
422 malware-scanning framework. This is intended purely as a debugging aid
423 to ensure that Exim's scanning is working, not to replace other tools.
424 Note that the ACL framework is not invoked, so if av_scanner references
425 ACL variables without a fallback then this will fail.
427 5. There is a new expansion operator, "reverse_ip", which will reverse IP
428 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
430 ${reverse_ip:192.0.2.4}
432 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
433 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
435 6. There is a new ACL control called "debug", to enable debug logging.
436 This allows selective logging of certain incoming transactions within
437 production environments, with some care. It takes two options, "tag"
438 and "opts"; "tag" is included in the filename of the log and "opts"
439 is used as per the -d<options> command-line option. Examples, which
440 don't all make sense in all contexts:
443 control = debug/tag=.$sender_host_address
444 control = debug/opts=+expand+acl
445 control = debug/tag=.$message_exim_id/opts=+expand
447 7. It has always been implicit in the design and the documentation that
448 "the Exim user" is not root. src/EDITME said that using root was
449 "very strongly discouraged". This is not enough to keep people from
450 shooting themselves in the foot in days when many don't configure Exim
451 themselves but via package build managers. The security consequences of
452 running various bits of network code are severe if there should be bugs in
453 them. As such, the Exim user may no longer be root. If configured
454 statically, Exim will refuse to build. If configured as ref:user then Exim
455 will exit shortly after start-up. If you must shoot yourself in the foot,
456 then henceforth you will have to maintain your own local patches to strip
459 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
460 condition logic to determine truth/failure and will fail to expand many
461 strings, bool_lax{} uses the router condition logic, where most strings
463 Note: bool{00} is false, bool_lax{00} is true.
465 9. Routers now support multiple "condition" tests.
467 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
468 Setting this allows an admin to define which entry in the tcpwrappers
469 config file will be used to control access to the daemon. This option
470 is only available when Exim is built with USE_TCP_WRAPPERS. The
471 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
474 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
475 the Exim run-time user, instead of root.
477 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
478 is forced on. This is mitigated by the new build option
479 TRUSTED_CONFIG_LIST which defines a list of configuration files which
480 are trusted; one per line. If a config file is owned by root and matches
481 a pathname in the list, then it may be invoked by the Exim build-time
482 user without Exim relinquishing root privileges.
484 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
485 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
486 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
487 include the main config. As a transition mechanism, we are temporarily
488 providing a work-around: the new build option WHITELIST_D_MACROS provides
489 a colon-separated list of macro names which may be overridden by the Exim
490 run-time user. The values of these macros are constrained to the regex
491 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
497 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
498 writable, the other to locking of MBX folders (not mbox).
500 2. MySQL stored procedures are now supported.
502 3. The dkim_domain transport option is now a list, not a single string, and
503 messages will be signed for each element in the list (discarding
506 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
507 in the presence of multiple character strings within the RR. Prior to 4.70,
508 only the first string would be returned. The dnsdb lookup now, by default,
509 preserves the pre-4.70 semantics, but also now takes an extended output
510 separator specification. The separator can be followed by a semicolon, to
511 concatenate the individual text strings together with no join character,
512 or by a comma and a second separator character, in which case the text
513 strings within a TXT record are joined on that second character.
514 Administrators are reminded that DNS provides no ordering guarantees
515 between multiple records in an RRset. For example:
517 foo.example. IN TXT "a" "b" "c"
518 foo.example. IN TXT "d" "e" "f"
520 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
521 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
522 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
528 1. Native DKIM support without an external library.
529 (Note that if no action to prevent it is taken, a straight upgrade will
530 result in DKIM verification of all signed incoming emails. See spec
531 for details on conditionally disabling)
533 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
535 3. There is now a bool{} expansion condition which maps certain strings to
536 true/false condition values (most likely of use in conjunction with the
537 and{} expansion operator).
539 4. The $spam_score, $spam_bar and $spam_report variables are now available
542 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
543 options, provided that Exim is invoked by an admin_user.
545 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
546 which increases compatibility with older clients at the cost of decreased
547 security. Don't set this unless you need to support such clients.
549 7. There is a new expansion operator, ${randint:...} which will produce a
550 "random" number less than the supplied integer. This randomness is
551 not guaranteed to be cryptographically strong, but depending upon how
552 Exim was built may be better than the most naive schemes.
554 8. Exim now explicitly ensures that SHA256 is available when linked against
557 9. The transport_filter_timeout option now applies to SMTP transports too.
563 1. Preliminary DKIM support in Experimental.
569 1. The body_linecount and body_zerocount C variables are now exported in the
572 2. When a dnslists lookup succeeds, the key that was looked up is now placed
573 in $dnslist_matched. When the key is an IP address, it is not reversed in
574 this variable (though it is, of course, in the actual lookup). In simple
577 deny dnslists = spamhaus.example
579 the key is also available in another variable (in this case,
580 $sender_host_address). In more complicated cases, however, this is not
581 true. For example, using a data lookup might generate a dnslists lookup
584 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
586 If this condition succeeds, the value in $dnslist_matched might be
587 192.168.6.7 (for example).
589 3. Authenticators now have a client_condition option. When Exim is running as
590 a client, it skips an authenticator whose client_condition expansion yields
591 "0", "no", or "false". This can be used, for example, to skip plain text
592 authenticators when the connection is not encrypted by a setting such as:
594 client_condition = ${if !eq{$tls_cipher}{}}
596 Note that the 4.67 documentation states that $tls_cipher contains the
597 cipher used for incoming messages. In fact, during SMTP delivery, it
598 contains the cipher used for the delivery. The same is true for
601 4. There is now a -Mvc <message-id> option, which outputs a copy of the
602 message to the standard output, in RFC 2822 format. The option can be used
603 only by an admin user.
605 5. There is now a /noupdate option for the ratelimit ACL condition. It
606 computes the rate and checks the limit as normal, but it does not update
607 the saved data. This means that, in relevant ACLs, it is possible to lookup
608 the existence of a specified (or auto-generated) ratelimit key without
609 incrementing the ratelimit counter for that key.
611 In order for this to be useful, another ACL entry must set the rate
612 for the same key somewhere (otherwise it will always be zero).
617 # Read the rate; if it doesn't exist or is below the maximum
619 deny ratelimit = 100 / 5m / strict / noupdate
620 log_message = RATE: $sender_rate / $sender_rate_period \
621 (max $sender_rate_limit)
623 [... some other logic and tests...]
625 warn ratelimit = 100 / 5m / strict / per_cmd
626 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
627 (max $sender_rate_limit)
628 condition = ${if le{$sender_rate}{$sender_rate_limit}}
632 6. The variable $max_received_linelength contains the number of bytes in the
633 longest line that was received as part of the message, not counting the
634 line termination character(s).
636 7. Host lists can now include +ignore_defer and +include_defer, analagous to
637 +ignore_unknown and +include_unknown. These options should be used with
638 care, probably only in non-critical host lists such as whitelists.
640 8. There's a new option called queue_only_load_latch, which defaults true.
641 If set false when queue_only_load is greater than zero, Exim re-evaluates
642 the load for each incoming message in an SMTP session. Otherwise, once one
643 message is queued, the remainder are also.
645 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
646 cases when an SMTP session ends without sending QUIT. However, when Exim
647 itself is is bad trouble, such as being unable to write to its log files,
648 this ACL is not run, because it might try to do things (such as write to
649 log files) that make the situation even worse.
651 Like the QUIT ACL, this new ACL is provided to make it possible to gather
652 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
653 modifier is forbidden in this ACL.
655 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
656 to a string that indicates the reason for the termination of the SMTP
657 connection. The possible values are:
659 acl-drop Another ACL issued a "drop" command
660 bad-commands Too many unknown or non-mail commands
661 command-timeout Timeout while reading SMTP commands
662 connection-lost The SMTP connection has been lost
663 data-timeout Timeout while reading message data
664 local-scan-error The local_scan() function crashed
665 local-scan-timeout The local_scan() function timed out
666 signal-exit SIGTERM or SIGINT
667 synchronization-error SMTP synchronization error
668 tls-failed TLS failed to start
670 In most cases when an SMTP connection is closed without having received
671 QUIT, Exim sends an SMTP response message before actually closing the
672 connection. With the exception of acl-drop, the default message can be
673 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
674 "drop" verb in another ACL, it is the message from the other ACL that is
677 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
678 servers with individual queries. This is done by starting the query with
679 "servers=x:y:z;", where each item in the list may take one of two forms:
681 (1) If it is just a host name, the appropriate global option (mysql_servers
682 or pgsql_servers) is searched for a host of the same name, and the
683 remaining parameters (database, user, password) are taken from there.
685 (2) If it contains any slashes, it is taken as a complete parameter set.
687 The list of servers is used in exactly the same was as the global list.
688 Once a connection to a server has happened and a query has been
689 successfully executed, processing of the lookup ceases.
691 This feature is intended for use in master/slave situations where updates
692 are occurring, and one wants to update a master rather than a slave. If the
693 masters are in the list for reading, you might have:
695 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
697 In an updating lookup, you could then write
699 ${lookup mysql{servers=master; UPDATE ...}
701 If, on the other hand, the master is not to be used for reading lookups:
703 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
705 you can still update the master by
707 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
709 11. The message_body_newlines option (default FALSE, for backwards
710 compatibility) can be used to control whether newlines are present in
711 $message_body and $message_body_end. If it is FALSE, they are replaced by
718 1. There is a new log selector called smtp_no_mail, which is not included in
719 the default setting. When it is set, a line is written to the main log
720 whenever an accepted SMTP connection terminates without having issued a
723 2. When an item in a dnslists list is followed by = and & and a list of IP
724 addresses, the behaviour was not clear when the lookup returned more than
725 one IP address. This has been solved by the addition of == and =& for "all"
726 rather than the default "any" matching.
728 3. Up till now, the only control over which cipher suites GnuTLS uses has been
729 for the cipher algorithms. New options have been added to allow some of the
730 other parameters to be varied.
732 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
733 set, Exim compiles a runtime option called disable_fsync.
735 5. There is a new variable called $smtp_count_at_connection_start.
737 6. There's a new control called no_pipelining.
739 7. There are two new variables called $sending_ip_address and $sending_port.
740 These are set whenever an SMTP connection to another host has been set up.
742 8. The expansion of the helo_data option in the smtp transport now happens
743 after the connection to the server has been made.
745 9. There is a new expansion operator ${rfc2047d: that decodes strings that
746 are encoded as per RFC 2047.
748 10. There is a new log selector called "pid", which causes the current process
749 id to be added to every log line, in square brackets, immediately after the
752 11. Exim has been modified so that it flushes SMTP output before implementing
753 a delay in an ACL. It also flushes the output before performing a callout,
754 as this can take a substantial time. These behaviours can be disabled by
755 obeying control = no_delay_flush or control = no_callout_flush,
756 respectively, at some earlier stage of the connection.
758 12. There are two new expansion conditions that iterate over a list. They are
759 called forany and forall.
761 13. There's a new global option called dsn_from that can be used to vary the
762 contents of From: lines in bounces and other automatically generated
763 messages ("delivery status notifications" - hence the name of the option).
765 14. The smtp transport has a new option called hosts_avoid_pipelining.
767 15. By default, exigrep does case-insensitive matches. There is now a -I option
768 that makes it case-sensitive.
770 16. A number of new features ("addresses", "map", "filter", and "reduce") have
771 been added to string expansions to make it easier to process lists of
772 items, typically addresses.
774 17. There's a new ACL modifier called "continue". It does nothing of itself,
775 and processing of the ACL always continues with the next condition or
776 modifier. It is provided so that the side effects of expanding its argument
779 18. It is now possible to use newline and other control characters (those with
780 values less than 32, plus DEL) as separators in lists.
782 19. The exigrep utility now has a -v option, which inverts the matching
785 20. The host_find_failed option in the manualroute router can now be set to
792 No new features were added to 4.66.
798 No new features were added to 4.65.
804 1. ACL variables can now be given arbitrary names, as long as they start with
805 "acl_c" or "acl_m" (for connection variables and message variables), are at
806 least six characters long, with the sixth character being either a digit or
809 2. There is a new ACL modifier called log_reject_target. It makes it possible
810 to specify which logs are used for messages about ACL rejections.
812 3. There is a new authenticator called "dovecot". This is an interface to the
813 authentication facility of the Dovecot POP/IMAP server, which can support a
814 number of authentication methods.
816 4. The variable $message_headers_raw provides a concatenation of all the
817 messages's headers without any decoding. This is in contrast to
818 $message_headers, which does RFC2047 decoding on the header contents.
820 5. In a DNS black list, if two domain names, comma-separated, are given, the
821 second is used first to do an initial check, making use of any IP value
822 restrictions that are set. If there is a match, the first domain is used,
823 without any IP value restrictions, to get the TXT record.
825 6. All authenticators now have a server_condition option.
827 7. There is a new command-line option called -Mset. It is useful only in
828 conjunction with -be (that is, when testing string expansions). It must be
829 followed by a message id; Exim loads the given message from its spool
830 before doing the expansions.
832 8. Another similar new command-line option is called -bem. It operates like
833 -be except that it must be followed by the name of a file that contains a
836 9. When an address is delayed because of a 4xx response to a RCPT command, it
837 is now the combination of sender and recipient that is delayed in
838 subsequent queue runs until its retry time is reached.
840 10. Unary negation and the bitwise logical operators and, or, xor, not, and
841 shift, have been added to the eval: and eval10: expansion items.
843 11. The variables $interface_address and $interface_port have been renamed
844 as $received_ip_address and $received_port, to make it clear that they
845 relate to message reception rather than delivery. (The old names remain
846 available for compatibility.)
848 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
849 to vary the message that is sent when an SMTP command is accepted.
855 1. There is a new Boolean option called filter_prepend_home for the redirect
858 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
859 start of receiving a non-SMTP message, before any of the message has been
862 3. When an SMTP error message is specified in a "message" modifier in an ACL,
863 or in a :fail: or :defer: message in a redirect router, Exim now checks the
864 start of the message for an SMTP error code.
866 4. There is a new parameter for LDAP lookups called "referrals", which takes
867 one of the settings "follow" (the default) or "nofollow".
869 5. Version 20070721.2 of exipick now included, offering these new options:
871 After all other sorting options have bee processed, reverse order
872 before displaying messages (-R is synonym).
874 Randomize order of matching messages before displaying.
876 Instead of displaying the matching messages, display the sum
878 --sort <variable>[,<variable>...]
879 Before displaying matching messages, sort the messages according to
880 each messages value for each variable.
882 Negate the value for every test (returns inverse output from the
883 same criteria without --not).
889 1. The ${readsocket expansion item now supports Internet domain sockets as well
890 as Unix domain sockets. If the first argument begins "inet:", it must be of
891 the form "inet:host:port". The port is mandatory; it may be a number or the
892 name of a TCP port in /etc/services. The host may be a name, or it may be an
893 IP address. An ip address may optionally be enclosed in square brackets.
894 This is best for IPv6 addresses. For example:
896 ${readsocket{inet:[::1]:1234}{<request data>}...
898 Only a single host name may be given, but if looking it up yield more than
899 one IP address, they are each tried in turn until a connection is made. Once
900 a connection has been made, the behaviour is as for ${readsocket with a Unix
903 2. If a redirect router sets up file or pipe deliveries for more than one
904 incoming address, and the relevant transport has batch_max set greater than
905 one, a batch delivery now occurs.
907 3. The appendfile transport has a new option called maildirfolder_create_regex.
908 Its value is a regular expression. For a maildir delivery, this is matched
909 against the maildir directory; if it matches, Exim ensures that a
910 maildirfolder file is created alongside the new, cur, and tmp directories.
916 The documentation is up-to-date for the 4.61 release. Major new features since
917 the 4.60 release are:
919 . An option called disable_ipv6, to disable the use of IPv6 completely.
921 . An increase in the number of ACL variables to 20 of each type.
923 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
924 $2, $3, (though those are still set) because the numeric variables get used
925 for other things in complicated expansions.
927 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
929 . It is possible to use setclassresources() on some BSD OS to control the
930 resources used in pipe deliveries.
932 . A new ACL modifier called add_header, which can be used with any verb.
934 . More errors are detectable in retry rules.
936 There are a number of other additions too.
942 The documentation is up-to-date for the 4.60 release. Major new features since
943 the 4.50 release are:
945 . Support for SQLite.
947 . Support for IGNOREQUOTA in LMTP.
949 . Extensions to the "submission mode" features.
951 . Support for Client SMTP Authorization (CSA).
953 . Support for ratelimiting hosts and users.
955 . New expansion items to help with the BATV "prvs" scheme.
957 . A "match_ip" condition, that matches an IP address against a list.
959 There are many more minor changes.
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