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, and a new sha256 operator
52 11. PRDR is now supported dy default.
58 1. New command-line option -bI:sieve will list all supported sieve extensions
59 of this Exim build on standard output, one per line.
60 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
61 query this to establish the correct list to include in the protocol's
62 SIEVE capability line.
64 2. If the -n option is combined with the -bP option, then the name of an
65 emitted option is not output, only the value (if visible to you).
66 For instance, "exim -n -bP pid_file_path" should just emit a pathname
67 followed by a newline, and no other text.
69 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
70 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
71 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
72 acceptable for security. (Option accepted but ignored if using OpenSSL).
73 Defaults to 1024, the old value. May be lowered only to 512, or raised as
74 far as you like. Raising this may hinder TLS interoperability with other
75 sites and is not currently recommended. Lowering this will permit you to
76 establish a TLS session which is not as secure as you might like.
78 Unless you really know what you are doing, leave it alone.
80 4. If not built with DISABLE_DNSSEC, Exim now has the main option
81 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
82 to send the DO flag to your recursive resolver. If you have a recursive
83 resolver, which can set the Authenticated Data (AD) flag in results, Exim
84 can now detect this. Exim does not perform validation itself, instead
85 relying upon a trusted path to the resolver.
87 Current status: work-in-progress; $sender_host_dnssec variable added.
89 5. DSCP support for outbound connections: on a transport using the smtp driver,
90 set "dscp = ef", for instance, to cause the connections to have the relevant
91 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
93 Similarly for inbound connections, there is a new control modifier, dscp,
94 so "warn control = dscp/ef" in the connect ACL, or after authentication.
96 Supported values depend upon system libraries. "exim -bI:dscp" to list the
97 ones Exim knows of. You can also set a raw number 0..0x3F.
99 6. The -G command-line flag is no longer ignored; it is now equivalent to an
100 ACL setting "control = suppress_local_fixups". The -L command-line flag
101 is now accepted and forces use of syslog, with the provided tag as the
102 process name. A few other flags used by Sendmail are now accepted and
105 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
106 ACL modifier; works for single-recipient mails which are recieved on and
107 deliverable via SMTP. Using the connection made for a recipient verify,
108 if requested before the verify, or a new one made for the purpose while
109 the inbound connection is still active. The bulk of the mail item is copied
110 direct from the inbound socket to the outbound (as well as the spool file).
111 When the source notifies the end of data, the data acceptance by the destination
112 is negociated before the acceptance is sent to the source. If the destination
113 does not accept the mail item, for example due to content-scanning, the item
114 is not accepted from the source and therefore there is no need to generate
115 a bounce mail. This is of benefit when providing a secondary-MX service.
116 The downside is that delays are under the control of the ultimate destination
119 The Recieved-by: header on items delivered by cutthrough is generated
120 early in reception rather than at the end; this will affect any timestamp
121 included. The log line showing delivery is recorded before that showing
122 reception; it uses a new ">>" tag instead of "=>".
124 To support the feature, verify-callout connections can now use ESMTP and TLS.
125 The usual smtp transport options are honoured, plus a (new, default everything)
126 hosts_verify_avoid_tls.
128 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
129 for specific access to the information for each connection. The old names
130 are present for now but deprecated.
132 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
134 8. New expansion operators ${listnamed:name} to get the content of a named list
135 and ${listcount:string} to count the items in a list.
137 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
138 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
139 modules. For some situations this is desirable, but we expect admin in
140 those situations to know they want the feature. More commonly, it means
141 that GUI user modules get loaded and are broken by the setuid Exim being
142 unable to access files specified in environment variables and passed
143 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
144 unless this new option is set.
146 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
147 so have also added a build option which can be used to build Exim with GnuTLS
148 but without trying to use any kind of PKCS11 support. Uncomment this in the
151 AVOID_GNUTLS_PKCS11=yes
153 10. The "acl = name" condition on an ACL now supports optional arguments.
154 New expansion item "${acl {name}{arg}...}" and expansion condition
155 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
156 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
157 Variable $acl_narg contains the number of arguments. If the ACL sets
158 a "message =" value this becomes the result of the expansion item,
159 or the value of $value for the expansion condition. If the ACL returns
160 accept the expansion condition is true; if reject, false. A defer
161 return results in a forced fail.
163 11. Routers and transports can now have multiple headers_add and headers_remove
164 option lines. The concatenated list is used.
166 12. New ACL modifier "remove_header" can remove headers before message gets
167 handled by routers/transports.
169 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
170 "aaaa" and "a" lookups is done and the full set of results returned.
172 14. New expansion variable $headers_added with content from ACL add_header
173 modifier (but not yet added to messsage).
175 15. New 8bitmime status logging option for received messages. Log field "M8S".
177 16. New authenticated_sender logging option, adding to log field "A".
179 17. New expansion variables $router_name and $transport_name. Useful
180 particularly for debug_print as -bt commandline option does not
181 require privilege whereas -d does.
183 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
184 proposed extension to SMTP from Eric Hall.
186 19. The pipe transport has gained the force_command option, to allow
187 decorating commands from user .forward pipe aliases with prefix
188 wrappers, for instance.
190 20. Callout connections can now AUTH; the same controls as normal delivery
193 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
194 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
195 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
196 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
197 dmarc_status. It adds new control flags dmarc_disable_verify and
198 dmarc_enable_forensic.
200 22. Add expansion variable $authenticated_fail_id, which is the username
201 provided to the authentication method which failed. It is available
202 for use in subsequent ACL processing (typically quit or notquit ACLs).
204 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
207 24. New ${hexquote:..string..} expansion operator converts non-printable
208 characters in the string to \xNN form.
210 25. Experimental TPDA (Transport Post Delivery Action) function added.
211 Patch provided by Axel Rau.
213 26. Experimental Redis lookup added. Patch provided by Warren Baker.
219 1. New authenticator driver, "gsasl". Server-only (at present).
220 This is a SASL interface, licensed under GPL, which can be found at
221 http://www.gnu.org/software/gsasl/.
222 This system does not provide sources of data for authentication, so
223 careful use needs to be made of the conditions in Exim.
225 2. New authenticator driver, "heimdal_gssapi". Server-only.
226 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
227 is no longer honoured for setuid programs by Heimdal. Use the
228 "server_keytab" option to point to the keytab.
230 3. The "pkg-config" system can now be used when building Exim to reference
231 cflags and library information for lookups and authenticators, rather
232 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
233 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
234 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
236 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
237 find the headers and libraries for PCRE.
239 4. New expansion variable $tls_bits.
241 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
242 be joined together with ASCII NUL characters to construct the key to pass
243 into the DBM library. Can be used with gsasl to access sasldb2 files as
246 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
248 Avoid release 1.0.1a if you can. Note that the default value of
249 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
250 increased susceptibility to attack. This may still have interoperability
251 implications for very old clients (see version 4.31 change 37) but
252 administrators can choose to make the trade-off themselves and restore
253 compatibility at the cost of session security.
255 7. Use of the new expansion variable $tls_sni in the main configuration option
256 tls_certificate will cause Exim to re-expand the option, if the client
257 sends the TLS Server Name Indication extension, to permit choosing a
258 different certificate; tls_privatekey will also be re-expanded. You must
259 still set these options to expand to valid files when $tls_sni is not set.
261 The SMTP Transport has gained the option tls_sni, which will set a hostname
262 for outbound TLS sessions, and set $tls_sni too.
264 A new log_selector, +tls_sni, has been added, to log received SNI values
265 for Exim as a server.
267 8. The existing "accept_8bitmime" option now defaults to true. This means
268 that Exim is deliberately not strictly RFC compliant. We're following
269 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
270 Those who disagree, or know that they are talking to mail servers that,
271 even today, are not 8-bit clean, need to turn off this option.
273 9. Exim can now be started with -bw (with an optional timeout, given as
274 -bw<timespec>). With this, stdin at startup is a socket that is
275 already listening for connections. This has a more modern name of
276 "socket activation", but forcing the activated socket to fd 0. We're
277 interested in adding more support for modern variants.
279 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
280 for numbers indicates multiplication by 1024^3.
282 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
283 gnutls_require_mac & gnutls_require_protocols are no longer supported.
284 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
285 string, documentation for which is at:
286 http://www.gnutls.org/manual/html_node/Priority-Strings.html
288 SNI support has been added to Exim's GnuTLS integration too.
290 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
291 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
293 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
294 is now available. If the contents of the file are valid, then Exim will
295 send that back in response to a TLS status request; this is OCSP Stapling.
296 Exim will not maintain the contents of the file in any way: administrators
297 are responsible for ensuring that it is up-to-date.
299 See "experimental-spec.txt" for more details.
301 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
302 identically to TXT record lookups.
304 14. New expansion variable $tod_epoch_l for higher-precision time.
306 15. New global option tls_dh_max_bits, defaulting to current value of NSS
307 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
308 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
310 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
311 Option can now be a path or an identifier for a standard prime.
312 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
313 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
316 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
317 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
318 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
324 1. New options for the ratelimit ACL condition: /count= and /unique=.
325 The /noupdate option has been replaced by a /readonly option.
327 2. The SMTP transport's protocol option may now be set to "smtps", to
328 use SSL-on-connect outbound.
330 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
331 there is a problem talking to the AV scanner, or the AV scanner running.
333 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
334 and check if the search item is a member of the list. This does not
335 support named lists, but does subject the list part to string expansion.
337 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
338 built, Exim no longer performs string expansion on the second string of
339 the match_* expansion conditions: "match_address", "match_domain",
340 "match_ip" & "match_local_part". Named lists can still be used.
346 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
347 or off in the resolver library.
353 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
354 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
355 libraries. The following global options have been added in support of
356 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
357 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
359 2. The pipe transport now takes a boolean option, "freeze_signal", default
360 false. When true, if the external delivery command exits on a signal then
361 Exim will freeze the message in the queue, instead of generating a bounce.
363 3. Log filenames may now use %M as an escape, instead of %D (still available).
364 The %M pattern expands to yyyymm, providing month-level resolution.
366 4. The $message_linecount variable is now updated for the maildir_tag option,
367 in the same way as $message_size, to reflect the real number of lines,
368 including any header additions or removals from transport.
370 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
371 Exim now selects entries randomly, to better scale in a cluster setup.
377 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
378 the flaw permitted the Exim run-time user to cause root to append to
379 arbitrary files of the attacker's choosing, with the content based
380 on content supplied by the attacker.
382 2. Exim now supports loading some lookup types at run-time, using your
383 platform's dlopen() functionality. This has limited platform support
384 and the intention is not to support every variant, it's limited to
385 dlopen(). This permits the main Exim binary to not be linked against
386 all the libraries needed for all the lookup types.
392 NOTE: this version is not guaranteed backwards-compatible, please read the
393 items below carefully
395 1. A new main configuration option, "openssl_options", is available if Exim
396 is built with SSL support provided by OpenSSL. The option allows
397 administrators to specify OpenSSL options to be used on connections;
398 typically this is to set bug compatibility features which the OpenSSL
399 developers have not enabled by default. There may be security
400 consequences for certain options, so these should not be changed
403 2. A new pipe transport option, "permit_coredumps", may help with problem
404 diagnosis in some scenarios. Note that Exim is typically installed as
405 a setuid binary, which on most OSes will inhibit coredumps by default,
406 so that safety mechanism would have to be overridden for this option to
407 be able to take effect.
409 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
410 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
411 Note that this switches Exim to use a new API ("INSTREAM") and a future
412 release of ClamAV will remove support for the old API ("STREAM").
414 The av_scanner option, when set to "clamd", now takes an optional third
415 part, "local", which causes Exim to pass a filename to ClamAV instead of
416 the file content. This is the same behaviour as when clamd is pointed at
417 a Unix-domain socket. For example:
419 av_scanner = clamd:192.0.2.3 1234:local
421 ClamAV's ExtendedDetectionInfo response format is now handled.
423 4. There is now a -bmalware option, restricted to admin users. This option
424 takes one parameter, a filename, and scans that file with Exim's
425 malware-scanning framework. This is intended purely as a debugging aid
426 to ensure that Exim's scanning is working, not to replace other tools.
427 Note that the ACL framework is not invoked, so if av_scanner references
428 ACL variables without a fallback then this will fail.
430 5. There is a new expansion operator, "reverse_ip", which will reverse IP
431 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
433 ${reverse_ip:192.0.2.4}
435 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
436 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
438 6. There is a new ACL control called "debug", to enable debug logging.
439 This allows selective logging of certain incoming transactions within
440 production environments, with some care. It takes two options, "tag"
441 and "opts"; "tag" is included in the filename of the log and "opts"
442 is used as per the -d<options> command-line option. Examples, which
443 don't all make sense in all contexts:
446 control = debug/tag=.$sender_host_address
447 control = debug/opts=+expand+acl
448 control = debug/tag=.$message_exim_id/opts=+expand
450 7. It has always been implicit in the design and the documentation that
451 "the Exim user" is not root. src/EDITME said that using root was
452 "very strongly discouraged". This is not enough to keep people from
453 shooting themselves in the foot in days when many don't configure Exim
454 themselves but via package build managers. The security consequences of
455 running various bits of network code are severe if there should be bugs in
456 them. As such, the Exim user may no longer be root. If configured
457 statically, Exim will refuse to build. If configured as ref:user then Exim
458 will exit shortly after start-up. If you must shoot yourself in the foot,
459 then henceforth you will have to maintain your own local patches to strip
462 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
463 condition logic to determine truth/failure and will fail to expand many
464 strings, bool_lax{} uses the router condition logic, where most strings
466 Note: bool{00} is false, bool_lax{00} is true.
468 9. Routers now support multiple "condition" tests.
470 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
471 Setting this allows an admin to define which entry in the tcpwrappers
472 config file will be used to control access to the daemon. This option
473 is only available when Exim is built with USE_TCP_WRAPPERS. The
474 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
477 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
478 the Exim run-time user, instead of root.
480 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
481 is forced on. This is mitigated by the new build option
482 TRUSTED_CONFIG_LIST which defines a list of configuration files which
483 are trusted; one per line. If a config file is owned by root and matches
484 a pathname in the list, then it may be invoked by the Exim build-time
485 user without Exim relinquishing root privileges.
487 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
488 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
489 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
490 include the main config. As a transition mechanism, we are temporarily
491 providing a work-around: the new build option WHITELIST_D_MACROS provides
492 a colon-separated list of macro names which may be overridden by the Exim
493 run-time user. The values of these macros are constrained to the regex
494 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
500 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
501 writable, the other to locking of MBX folders (not mbox).
503 2. MySQL stored procedures are now supported.
505 3. The dkim_domain transport option is now a list, not a single string, and
506 messages will be signed for each element in the list (discarding
509 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
510 in the presence of multiple character strings within the RR. Prior to 4.70,
511 only the first string would be returned. The dnsdb lookup now, by default,
512 preserves the pre-4.70 semantics, but also now takes an extended output
513 separator specification. The separator can be followed by a semicolon, to
514 concatenate the individual text strings together with no join character,
515 or by a comma and a second separator character, in which case the text
516 strings within a TXT record are joined on that second character.
517 Administrators are reminded that DNS provides no ordering guarantees
518 between multiple records in an RRset. For example:
520 foo.example. IN TXT "a" "b" "c"
521 foo.example. IN TXT "d" "e" "f"
523 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
524 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
525 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
531 1. Native DKIM support without an external library.
532 (Note that if no action to prevent it is taken, a straight upgrade will
533 result in DKIM verification of all signed incoming emails. See spec
534 for details on conditionally disabling)
536 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
538 3. There is now a bool{} expansion condition which maps certain strings to
539 true/false condition values (most likely of use in conjunction with the
540 and{} expansion operator).
542 4. The $spam_score, $spam_bar and $spam_report variables are now available
545 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
546 options, provided that Exim is invoked by an admin_user.
548 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
549 which increases compatibility with older clients at the cost of decreased
550 security. Don't set this unless you need to support such clients.
552 7. There is a new expansion operator, ${randint:...} which will produce a
553 "random" number less than the supplied integer. This randomness is
554 not guaranteed to be cryptographically strong, but depending upon how
555 Exim was built may be better than the most naive schemes.
557 8. Exim now explicitly ensures that SHA256 is available when linked against
560 9. The transport_filter_timeout option now applies to SMTP transports too.
566 1. Preliminary DKIM support in Experimental.
572 1. The body_linecount and body_zerocount C variables are now exported in the
575 2. When a dnslists lookup succeeds, the key that was looked up is now placed
576 in $dnslist_matched. When the key is an IP address, it is not reversed in
577 this variable (though it is, of course, in the actual lookup). In simple
580 deny dnslists = spamhaus.example
582 the key is also available in another variable (in this case,
583 $sender_host_address). In more complicated cases, however, this is not
584 true. For example, using a data lookup might generate a dnslists lookup
587 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
589 If this condition succeeds, the value in $dnslist_matched might be
590 192.168.6.7 (for example).
592 3. Authenticators now have a client_condition option. When Exim is running as
593 a client, it skips an authenticator whose client_condition expansion yields
594 "0", "no", or "false". This can be used, for example, to skip plain text
595 authenticators when the connection is not encrypted by a setting such as:
597 client_condition = ${if !eq{$tls_cipher}{}}
599 Note that the 4.67 documentation states that $tls_cipher contains the
600 cipher used for incoming messages. In fact, during SMTP delivery, it
601 contains the cipher used for the delivery. The same is true for
604 4. There is now a -Mvc <message-id> option, which outputs a copy of the
605 message to the standard output, in RFC 2822 format. The option can be used
606 only by an admin user.
608 5. There is now a /noupdate option for the ratelimit ACL condition. It
609 computes the rate and checks the limit as normal, but it does not update
610 the saved data. This means that, in relevant ACLs, it is possible to lookup
611 the existence of a specified (or auto-generated) ratelimit key without
612 incrementing the ratelimit counter for that key.
614 In order for this to be useful, another ACL entry must set the rate
615 for the same key somewhere (otherwise it will always be zero).
620 # Read the rate; if it doesn't exist or is below the maximum
622 deny ratelimit = 100 / 5m / strict / noupdate
623 log_message = RATE: $sender_rate / $sender_rate_period \
624 (max $sender_rate_limit)
626 [... some other logic and tests...]
628 warn ratelimit = 100 / 5m / strict / per_cmd
629 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
630 (max $sender_rate_limit)
631 condition = ${if le{$sender_rate}{$sender_rate_limit}}
635 6. The variable $max_received_linelength contains the number of bytes in the
636 longest line that was received as part of the message, not counting the
637 line termination character(s).
639 7. Host lists can now include +ignore_defer and +include_defer, analagous to
640 +ignore_unknown and +include_unknown. These options should be used with
641 care, probably only in non-critical host lists such as whitelists.
643 8. There's a new option called queue_only_load_latch, which defaults true.
644 If set false when queue_only_load is greater than zero, Exim re-evaluates
645 the load for each incoming message in an SMTP session. Otherwise, once one
646 message is queued, the remainder are also.
648 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
649 cases when an SMTP session ends without sending QUIT. However, when Exim
650 itself is is bad trouble, such as being unable to write to its log files,
651 this ACL is not run, because it might try to do things (such as write to
652 log files) that make the situation even worse.
654 Like the QUIT ACL, this new ACL is provided to make it possible to gather
655 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
656 modifier is forbidden in this ACL.
658 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
659 to a string that indicates the reason for the termination of the SMTP
660 connection. The possible values are:
662 acl-drop Another ACL issued a "drop" command
663 bad-commands Too many unknown or non-mail commands
664 command-timeout Timeout while reading SMTP commands
665 connection-lost The SMTP connection has been lost
666 data-timeout Timeout while reading message data
667 local-scan-error The local_scan() function crashed
668 local-scan-timeout The local_scan() function timed out
669 signal-exit SIGTERM or SIGINT
670 synchronization-error SMTP synchronization error
671 tls-failed TLS failed to start
673 In most cases when an SMTP connection is closed without having received
674 QUIT, Exim sends an SMTP response message before actually closing the
675 connection. With the exception of acl-drop, the default message can be
676 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
677 "drop" verb in another ACL, it is the message from the other ACL that is
680 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
681 servers with individual queries. This is done by starting the query with
682 "servers=x:y:z;", where each item in the list may take one of two forms:
684 (1) If it is just a host name, the appropriate global option (mysql_servers
685 or pgsql_servers) is searched for a host of the same name, and the
686 remaining parameters (database, user, password) are taken from there.
688 (2) If it contains any slashes, it is taken as a complete parameter set.
690 The list of servers is used in exactly the same was as the global list.
691 Once a connection to a server has happened and a query has been
692 successfully executed, processing of the lookup ceases.
694 This feature is intended for use in master/slave situations where updates
695 are occurring, and one wants to update a master rather than a slave. If the
696 masters are in the list for reading, you might have:
698 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
700 In an updating lookup, you could then write
702 ${lookup mysql{servers=master; UPDATE ...}
704 If, on the other hand, the master is not to be used for reading lookups:
706 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
708 you can still update the master by
710 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
712 11. The message_body_newlines option (default FALSE, for backwards
713 compatibility) can be used to control whether newlines are present in
714 $message_body and $message_body_end. If it is FALSE, they are replaced by
721 1. There is a new log selector called smtp_no_mail, which is not included in
722 the default setting. When it is set, a line is written to the main log
723 whenever an accepted SMTP connection terminates without having issued a
726 2. When an item in a dnslists list is followed by = and & and a list of IP
727 addresses, the behaviour was not clear when the lookup returned more than
728 one IP address. This has been solved by the addition of == and =& for "all"
729 rather than the default "any" matching.
731 3. Up till now, the only control over which cipher suites GnuTLS uses has been
732 for the cipher algorithms. New options have been added to allow some of the
733 other parameters to be varied.
735 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
736 set, Exim compiles a runtime option called disable_fsync.
738 5. There is a new variable called $smtp_count_at_connection_start.
740 6. There's a new control called no_pipelining.
742 7. There are two new variables called $sending_ip_address and $sending_port.
743 These are set whenever an SMTP connection to another host has been set up.
745 8. The expansion of the helo_data option in the smtp transport now happens
746 after the connection to the server has been made.
748 9. There is a new expansion operator ${rfc2047d: that decodes strings that
749 are encoded as per RFC 2047.
751 10. There is a new log selector called "pid", which causes the current process
752 id to be added to every log line, in square brackets, immediately after the
755 11. Exim has been modified so that it flushes SMTP output before implementing
756 a delay in an ACL. It also flushes the output before performing a callout,
757 as this can take a substantial time. These behaviours can be disabled by
758 obeying control = no_delay_flush or control = no_callout_flush,
759 respectively, at some earlier stage of the connection.
761 12. There are two new expansion conditions that iterate over a list. They are
762 called forany and forall.
764 13. There's a new global option called dsn_from that can be used to vary the
765 contents of From: lines in bounces and other automatically generated
766 messages ("delivery status notifications" - hence the name of the option).
768 14. The smtp transport has a new option called hosts_avoid_pipelining.
770 15. By default, exigrep does case-insensitive matches. There is now a -I option
771 that makes it case-sensitive.
773 16. A number of new features ("addresses", "map", "filter", and "reduce") have
774 been added to string expansions to make it easier to process lists of
775 items, typically addresses.
777 17. There's a new ACL modifier called "continue". It does nothing of itself,
778 and processing of the ACL always continues with the next condition or
779 modifier. It is provided so that the side effects of expanding its argument
782 18. It is now possible to use newline and other control characters (those with
783 values less than 32, plus DEL) as separators in lists.
785 19. The exigrep utility now has a -v option, which inverts the matching
788 20. The host_find_failed option in the manualroute router can now be set to
795 No new features were added to 4.66.
801 No new features were added to 4.65.
807 1. ACL variables can now be given arbitrary names, as long as they start with
808 "acl_c" or "acl_m" (for connection variables and message variables), are at
809 least six characters long, with the sixth character being either a digit or
812 2. There is a new ACL modifier called log_reject_target. It makes it possible
813 to specify which logs are used for messages about ACL rejections.
815 3. There is a new authenticator called "dovecot". This is an interface to the
816 authentication facility of the Dovecot POP/IMAP server, which can support a
817 number of authentication methods.
819 4. The variable $message_headers_raw provides a concatenation of all the
820 messages's headers without any decoding. This is in contrast to
821 $message_headers, which does RFC2047 decoding on the header contents.
823 5. In a DNS black list, if two domain names, comma-separated, are given, the
824 second is used first to do an initial check, making use of any IP value
825 restrictions that are set. If there is a match, the first domain is used,
826 without any IP value restrictions, to get the TXT record.
828 6. All authenticators now have a server_condition option.
830 7. There is a new command-line option called -Mset. It is useful only in
831 conjunction with -be (that is, when testing string expansions). It must be
832 followed by a message id; Exim loads the given message from its spool
833 before doing the expansions.
835 8. Another similar new command-line option is called -bem. It operates like
836 -be except that it must be followed by the name of a file that contains a
839 9. When an address is delayed because of a 4xx response to a RCPT command, it
840 is now the combination of sender and recipient that is delayed in
841 subsequent queue runs until its retry time is reached.
843 10. Unary negation and the bitwise logical operators and, or, xor, not, and
844 shift, have been added to the eval: and eval10: expansion items.
846 11. The variables $interface_address and $interface_port have been renamed
847 as $received_ip_address and $received_port, to make it clear that they
848 relate to message reception rather than delivery. (The old names remain
849 available for compatibility.)
851 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
852 to vary the message that is sent when an SMTP command is accepted.
858 1. There is a new Boolean option called filter_prepend_home for the redirect
861 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
862 start of receiving a non-SMTP message, before any of the message has been
865 3. When an SMTP error message is specified in a "message" modifier in an ACL,
866 or in a :fail: or :defer: message in a redirect router, Exim now checks the
867 start of the message for an SMTP error code.
869 4. There is a new parameter for LDAP lookups called "referrals", which takes
870 one of the settings "follow" (the default) or "nofollow".
872 5. Version 20070721.2 of exipick now included, offering these new options:
874 After all other sorting options have bee processed, reverse order
875 before displaying messages (-R is synonym).
877 Randomize order of matching messages before displaying.
879 Instead of displaying the matching messages, display the sum
881 --sort <variable>[,<variable>...]
882 Before displaying matching messages, sort the messages according to
883 each messages value for each variable.
885 Negate the value for every test (returns inverse output from the
886 same criteria without --not).
892 1. The ${readsocket expansion item now supports Internet domain sockets as well
893 as Unix domain sockets. If the first argument begins "inet:", it must be of
894 the form "inet:host:port". The port is mandatory; it may be a number or the
895 name of a TCP port in /etc/services. The host may be a name, or it may be an
896 IP address. An ip address may optionally be enclosed in square brackets.
897 This is best for IPv6 addresses. For example:
899 ${readsocket{inet:[::1]:1234}{<request data>}...
901 Only a single host name may be given, but if looking it up yield more than
902 one IP address, they are each tried in turn until a connection is made. Once
903 a connection has been made, the behaviour is as for ${readsocket with a Unix
906 2. If a redirect router sets up file or pipe deliveries for more than one
907 incoming address, and the relevant transport has batch_max set greater than
908 one, a batch delivery now occurs.
910 3. The appendfile transport has a new option called maildirfolder_create_regex.
911 Its value is a regular expression. For a maildir delivery, this is matched
912 against the maildir directory; if it matches, Exim ensures that a
913 maildirfolder file is created alongside the new, cur, and tmp directories.
919 The documentation is up-to-date for the 4.61 release. Major new features since
920 the 4.60 release are:
922 . An option called disable_ipv6, to disable the use of IPv6 completely.
924 . An increase in the number of ACL variables to 20 of each type.
926 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
927 $2, $3, (though those are still set) because the numeric variables get used
928 for other things in complicated expansions.
930 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
932 . It is possible to use setclassresources() on some BSD OS to control the
933 resources used in pipe deliveries.
935 . A new ACL modifier called add_header, which can be used with any verb.
937 . More errors are detectable in retry rules.
939 There are a number of other additions too.
945 The documentation is up-to-date for the 4.60 release. Major new features since
946 the 4.50 release are:
948 . Support for SQLite.
950 . Support for IGNOREQUOTA in LMTP.
952 . Extensions to the "submission mode" features.
954 . Support for Client SMTP Authorization (CSA).
956 . Support for ratelimiting hosts and users.
958 . New expansion items to help with the BATV "prvs" scheme.
960 . A "match_ip" condition, that matches an IP address against a list.
962 There are many more minor changes.
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