1 $Cambridge: exim/doc/doc-txt/NewStuff,v 1.18 2004/11/25 13:54:31 ph10 Exp $
6 This file contains descriptions of new features that have been added to Exim,
7 but have not yet made it into the main manual (which is most conveniently
8 updated when there is a relatively large batch of changes). The doc/ChangeLog
9 file contains a listing of all changes, including bug fixes.
15 1. There is a new build-time option called CONFIGURE_GROUP which works like
16 CONFIGURE_OWNER. It specifies one additional group that is permitted for
17 the runtime configuration file when the group write permission is set.
19 2. The "control=submission" facility has a new option /sender_retain. This
20 has the effect of setting local_sender_retain true and local_from_check
21 false for the incoming message in which it is encountered.
23 3. $recipients is now available in the predata ACL (oversight).
25 4. The value of address_data from a sender verification is now available in
26 $sender_address_data in subsequent conditions in the ACL statement. Note:
27 this is just like $address_data. The value does not persist after the end
28 of the current ACL statement. If you want to preserve it, you can use one
31 5. The redirect router has two new options: forbid_sieve_filter and
32 forbid_exim_filter. When filtering is enabled by allow_filter, these
33 options control which type(s) of filtering are permitted. By default, both
34 Exim and Sieve filters are allowed.
36 6. A new option for callouts makes it possible to set a different (usually
37 smaller) timeout for making the SMTP connection. The keyword is "connect".
40 verify = sender/callout=5s,connect=1s
42 If not specified, it defaults to the general timeout value.
44 7. The new variables $sender_verify_failure and $recipient_verify_failure
45 contain information about exactly what failed. In an ACL, after one of
46 these failures, the relevant variable contains one of the following words:
48 qualify the address was unqualified (no domain), and the message
49 was neither local nor came from an exempted host;
53 mail routing succeeded, and a callout was attempted; rejection
54 occurred at or before the MAIL command (that is, on initial
55 connection, HELO, or MAIL);
57 recipient the RCPT command in a callout was rejected;
59 postmaster the postmaster check in a callout was rejected.
61 The main use of these variables is expected to be to distinguish between
62 rejections of MAIL and rejections of RCPT.
64 8. The command line option -dd behaves exactly like -d except when used on a
65 command that starts a daemon process. In that case, debugging is turned off
66 for the subprocesses that the daemon creates. Thus, it is useful for
67 monitoring the behaviour of the daemon without creating as much output as
70 9. $host_address is now set to the target address during the checking of
73 10. There are four new variables called $spool_space, $log_space,
74 $spool_inodes, and $log_inodes. The first two contain the amount of free
75 space in the disk partitions where Exim has its spool directory and log
76 directory, respectively. (When these are in the same partition, the values
77 will, of course, be the same.) The second two variables contain the numbers
78 of free inodes in the respective partitions.
80 NOTE: Because disks can nowadays be very large, the values in the space
81 variables are in kilobytes rather than in bytes. Thus, for example, to
82 check in an ACL that there is at least 50M free on the spool, you would
85 condition = ${if > {$spool_space}{50000}{yes}{no}}
87 The values are recalculated whenever any of these variables is referenced.
88 If the relevant file system does not have the concept of inodes, the value
89 of those variables is -1. If the operating system does not have the ability
90 to find the amount of free space (only true for experimental systems), the
93 11. It is now permitted to omit both strings after an "if" condition; if the
94 condition is true, the result is the string "true". As before, when the
95 second string is omitted, a false condition yields an empty string. This
96 makes it less cumbersome to write custom ACL and router conditions. For
99 condition = ${if eq {$acl_m4}{1}{yes}{no}}
103 condition = ${if eq {$acl_m4}{1}{yes}}
105 (because the second string has always defaulted to ""), you can now write
107 condition = ${if eq {$acl_m4}{1}}
109 Previously this was a syntax error.
111 12. There is a new "record type" that can be specified in dnsdb lookups. It
112 is "zns" (for "zone NS"). It performs a lookup for NS records on the given
113 domain, but if none are found, it removes the first component of the domain
114 name, and tries again. This process continues until NS records are found
115 or there are no more components left (or there's a DNS error). In other
116 words, it may return the name servers for a top-level domain, but it never
117 returns the root name servers. If there are no NS records for the top-level
118 domain, the lookup fails.
120 For example, ${lookup dnsdb{zns=xxx.quercite.com}} returns the name
121 servers for quercite.com, whereas ${lookup dnsdb{zns=xxx.edu}} returns
122 the name servers for edu, assuming in each case that there are no NS
123 records for the full domain name.
125 You should be careful about how you use this lookup because, unless the
126 top-level domain does not exist, the lookup will always return some host
127 names. The sort of use to which this might be put is for seeing if the name
128 servers for a given domain are on a blacklist. You can probably assume that
129 the name servers for the high-level domains such as .com or .co.uk are not
130 going to be on such a list.
132 13. Another new "record type" is "mxh"; this looks up MX records just as "mx"
133 does, but it returns only the names of the hosts, omitting the priority
136 14. It is now possible to specify a list of domains or IP addresses to be
137 looked up in a dnsdb lookup. The list is specified in the normal Exim way,
138 with colon as the default separator, but with the ability to change this.
141 ${lookup dnsdb{one.domain.com:two.domain.com}}
142 ${lookup dnsdb{a=one.host.com:two.host.com}}
143 ${lookup dnsdb{ptr = <; 1.2.3.4 ; 4.5.6.8}}
145 In order to retain backwards compatibility, there is one special case: if
146 the lookup type is PTR and no change of separator is specified, Exim looks
147 to see if the rest of the string is precisely one IPv6 address. In this
148 case, it does not treat it as a list.
150 The data from each lookup is concatenated, with newline separators (by
151 default - see 14 below), in the same way that multiple DNS records for a
152 single item are handled.
154 The lookup fails only if all the DNS lookups fail. As long as at least one
155 of them yields some data, the lookup succeeds. However, if there is a
156 temporary DNS error for any of them, the lookup defers.
158 15. It is now possible to specify the character to be used as a separator when
159 a dnsdb lookup returns data from more than one DNS record. The default is a
160 newline. To specify a different character, put '>' followed by the new
161 character at the start of the query. For example:
163 ${lookup dnsdb{>: a=h1.test.ex:h2.test.ex}}
164 ${lookup dnsdb{>| mxh=<;m1.test.ex;m2.test.ex}}
166 It is permitted to specify a space as the separator character. Note that
167 more than one DNS record can be found for a single lookup item; this
168 feature is relevant even when you do not specify a list.
170 The same effect could be achieved by wrapping the lookup in ${tr...}; this
171 feature is just a syntactic simplification.
173 16. It is now possible to supply a list of domains and/or IP addresses to be
174 lookup up in a DNS blacklist. Previously, only a single domain name could
175 be given, for example:
177 dnslists = black.list.tld/$sender_host_name
179 What follows the slash can now be a list. As with all lists, the default
180 separator is a colon. However, because this is a sublist within the list of
181 DNS blacklist domains, it is necessary either to double the separators like
184 dnslists = black.list.tld/name.1::name.2
186 or to change the separator character, like this:
188 dnslists = black.list.tld/<;name.1;name.2
190 If an item in the list is an IP address, it is inverted before the DNS
191 blacklist domain is appended. If it is not an IP address, no inversion
192 occurs. Consider this condition:
194 dnslists = black.list.tls/<;192.168.1.2;a.domain
196 The DNS lookups that occur are for
198 2.1.168.192.black.list.tld and a.domain.black.list.tld
200 Once a DNS record has been found (that matches a specific IP return
201 address, if specified), no further lookups are done.
203 17. The log selector queue_time_overall causes Exim to output the time spent on
204 the queue as an addition to the "Completed" message. Like queue_time (which
205 puts the queue time on individual delivery lines), the time is tagged with
206 "QT=", and it is measured from the time that the message starts to be
207 received, so it includes the reception time.
209 18. It is now possible to use both -bF and -bf on the same command, in order to
210 test a system filter and a user filter in the same run. For example:
212 exim -bF /system/filter -bf /user/filter </test/message
214 This is helpful when the system filter adds header lines or sets filter
215 variables that are used by the user filter.
221 1. There is a new Boolean global option called mua_wrapper, defaulting false.
222 This causes Exim to run an a restricted mode, in order to provide a very
225 Background: On a personal computer, it is a common requirement for all
226 email to be sent to a smarthost. There are plenty of MUAs that can be
227 configured to operate that way, for all the popular operating systems.
228 However, there are MUAs for Unix-like systems that cannot be so configured:
229 they submit messages using the command line interface of
230 /usr/sbin/sendmail. In addition, utility programs such as cron submit
233 Requirement: The requirement is for something that can provide the
234 /usr/sbin/sendmail interface and deliver messages to a smarthost, but not
235 provide any queueing or retrying facilities. Furthermore, the delivery to
236 the smarthost should be synchronous, so that if it fails, the sending MUA
237 is immediately informed. In other words, we want something that in effect
238 converts a command-line MUA into a TCP/SMTP MUA.
240 Solutions: There are a number of applications (for example, ssmtp) that do
241 this job. However, people have found them to be lacking in various ways.
242 For instance, some sites want to allow aliasing and forwarding before
243 sending to the smarthost.
245 Using Exim: Exim already had the necessary infrastructure for doing this
246 job. Just a few tweaks were needed to make it behave as required, though it
247 is somewhat of an overkill to use a fully-featured MTA for this purpose.
249 Setting mua_wrapper=true causes Exim to run in a special mode where it
250 assumes that it is being used to "wrap" a command-line MUA in the manner
253 If you set mua_wrapper=true, you also need to provide a compatible router
254 and transport configuration. Typically there will be just one router and
255 one transport, sending everything to a smarthost.
257 When run in MUA wrapping mode, the behaviour of Exim changes in the
260 (a) A daemon cannot be run, nor will Exim accept incoming messages from
261 inetd. In other words, the only way to submit messages is via the
264 (b) Each message is synchonously delivered as soon as it is received (-odi
265 is assumed). All queueing options (queue_only, queue_smtp_domains,
266 control=queue, control=freeze in an ACL etc.) are quietly ignored. The
267 Exim reception process does not finish until the delivery attempt is
268 complete. If the delivery was successful, a zero return code is given.
270 (c) Address redirection is permitted, but the final routing for all
271 addresses must be to the same remote transport, and to the same list of
272 hosts. Furthermore, the return_address must be the same for all
273 recipients, as must any added or deleted header lines. In other words,
274 it must be possible to deliver the message in a single SMTP
275 transaction, however many recipients there are.
277 (d) If the conditions in (c) are not met, or if routing any address results
278 in a failure or defer status, or if Exim is unable to deliver all the
279 recipients successfully to one of the hosts immediately, delivery of
280 the entire message fails.
282 (e) Because no queueing is allowed, all failures are treated as permanent;
283 there is no distinction between 4xx and 5xx SMTP response codes from
284 the smarthost. Furthermore, because only a single yes/no response can
285 be given to the caller, it is not possible to deliver to some
286 recipients and not others. If there is an error (temporary or
287 permanent) for any recipient, all are failed.
289 (f) If more than one host is listed, Exim will try another host after a
290 connection failure or a timeout, in the normal way. However, if this
291 kind of failure happens for all the hosts, the delivery fails.
293 (g) When delivery fails, an error message is written to the standard error
294 stream (as well as to Exim's log), and Exim exits to the caller with a
295 return code value 1. The message is expunged from Exim's spool files.
296 No bounce messages are ever generated.
298 (h) No retry data is maintained, and any retry rules are ignored.
300 (i) A number of Exim options are overridden: deliver_drop_privilege is
301 forced true, max_rcpt in the smtp transport is forced to "unlimited",
302 remote_max_parallel is forced to one, and fallback hosts are ignored.
304 The overall effect is that Exim makes a single synchronous attempt to
305 deliver the message, failing if there is any kind of problem. Because no
306 local deliveries are done and no daemon can be run, Exim does not need root
307 privilege. It should be possible to run it setuid=exim instead of
308 setuid=root. See section 48.3 in the 4.40 manual for a general discussion
309 about the advantages and disadvantages of running without root privilege.
311 2. There have been problems with DNS servers when SRV records are looked up.
312 Some mis-behaving servers return a DNS error or timeout when a non-existent
313 SRV record is sought. Similar problems have in the past been reported for
314 MX records. The global dns_again_means_nonexist option can help with this
315 problem, but it is heavy-handed because it is a global option. There are
316 now two new options for the dnslookup router. They are called
317 srv_fail_domains and mx_fail_domains. In each case, the value is a domain
318 list. If an attempt to look up an SRV or MX record results in a DNS failure
319 or "try again" response, and the domain matches the relevant list, Exim
320 behaves as if the DNS had responded "no such record". In the case of an SRV
321 lookup, this means that the router proceeds to look for MX records; in the
322 case of an MX lookup, it proceeds to look for A or AAAA records, unless the
323 domain matches mx_domains.
325 3. The following functions are now available in the local_scan() API:
327 (a) void header_remove(int occurrence, uschar *name)
329 This function removes header lines. If "occurrence" is zero or negative,
330 all occurrences of the header are removed. If occurrence is greater
331 than zero, that particular instance of the header is removed. If no
332 header(s) can be found that match the specification, the function does
335 (b) BOOL header_testname(header_line *hdr, uschar *name, int length,
338 This function tests whether the given header has the given name. It
339 is not just a string comparison, because whitespace is permitted
340 between the name and the colon. If the "notdel" argument is TRUE, a
341 FALSE return is forced for all "deleted" headers; otherwise they are
342 not treated specially. For example:
344 if (header_testname(h, US"X-Spam", 6, TRUE)) ...
346 (c) void header_add_at_position(BOOL after, uschar *name, BOOL topnot,
347 int type, char *format, ...)
349 This function adds a new header line at a specified point in the header
350 chain. If "name" is NULL, the new header is added at the end of the
351 chain if "after" is TRUE, or at the start if "after" is FALSE. If
352 "name" is not NULL, the headers are searched for the first non-deleted
353 header that matches the name. If one is found, the new header is added
354 before it if "after" is FALSE. If "after" is true, the new header is
355 added after the found header and any adjacent subsequent ones with the
356 same name (even if marked "deleted"). If no matching non-deleted header
357 is found, the "topnot" option controls where the header is added. If it
358 is TRUE, addition is at the top; otherwise at the bottom. Thus, to add
359 a header after all the Received: headers, or at the top if there are no
360 Received: headers, you could use
362 header_add_at_position(TRUE, US"Received", TRUE, ' ', "X-xxx: ...");
364 Normally, there is always at least one non-deleted Received: header,
365 but there may not be if received_header_text expands to an empty
368 (d) BOOL receive_remove_recipient(uschar *recipient)
370 This is a convenience function to remove a named recipient from the
371 list of recipients. It returns TRUE if a recipient was removed, and
372 FALSE if no matching recipient could be found. The argument must be a
373 complete email address.
375 4. When an ACL "warn" statement adds one or more header lines to a message,
376 they are added at the end of the existing header lines by default. It is
377 now possible to specify that any particular header line should be added
378 right at the start (before all the Received: lines) or immediately after
379 the first block of Received: lines in the message. This is done by
380 specifying :at_start: or :after_received: (or, for completeness, :at_end:)
381 before the text of the header line. (Header text cannot start with a colon,
382 as there has to be a header name first.) For example:
384 warn message = :after_received:X-My-Header: something or other...
386 If more than one header is supplied in a single warn statement, each one is
387 treated independently and can therefore be placed differently. If you add
388 more than one line at the start, or after the Received: block, they will
389 end up in reverse order.
391 Warning: This facility currently applies only to header lines that are
392 added in an ACL. It does NOT work for header lines that are added in a
393 system filter or in a router or transport.
395 5. There is now a new error code that can be used in retry rules. Its name is
396 "rcpt_4xx", and there are three forms. A literal "rcpt_4xx" matches any 4xx
397 error received for an outgoing SMTP RCPT command; alternatively, either the
398 first or both of the x's can be given as digits, for example: "rcpt_45x" or
399 "rcpt_436". If you want (say) to recognize 452 errors given to RCPT
400 commands by a particular host, and have only a one-hour retry for them, you
401 can set up a retry rule of this form:
403 the.host.name rcpt_452 F,1h,10m
405 Naturally, this rule must come before any others that would match.
407 These new errors apply to both outgoing SMTP (the smtp transport) and
408 outgoing LMTP (either the lmtp transport, or the smtp transport in LMTP
409 mode). Note, however, that they apply only to responses to RCPT commands.
411 6. The "postmaster" option of the callout feature of address verification has
412 been extended to make it possible to use a non-empty MAIL FROM address when
413 checking a postmaster address. The new suboption is called "postmaster_
414 mailfrom", and you use it like this:
416 require verify = sender/callout=postmaster_mailfrom=abc@x.y.z
418 Providing this suboption causes the postmaster check to be done using the
419 given address. The original "postmaster" option is equivalent to
421 require verify = sender/callout=postmaster_mailfrom=
423 If both suboptions are present, the rightmost one overrides.
427 (1) If you use a non-empty sender address for postmaster checking, there is
428 the likelihood that the remote host will itself initiate a callout
429 check back to your host to check that address. As this is a "normal"
430 callout check, the sender will most probably be empty, thus avoiding
431 possible callout loops. However, to be on the safe side it would be
432 best to set up your own ACLs so that they do not do sender verification
433 checks when the recipient is the address you use for postmaster callout
436 (2) The caching arrangements for postmaster checking do NOT take account of
437 the sender address. It is assumed that either the empty address, or a
438 fixed non-empty address will be used. All that Exim remembers is that
439 the postmaster check for the domain succeeded or failed.
441 7. When verifying addresses in header lines using the verify=header_sender
442 option, Exim behaves by default as if the addresses are envelope sender
443 addresses from a message. Callout verification therefore tests to see
444 whether a bounce message could be delivered, by using an empty address in
445 the MAIL FROM command. However, it is arguable that these addresses might
446 never be used as envelope senders, and could therefore justifiably reject
447 bounce messages (empty senders). There is now an additional callout option
448 for verify=header_sender that allows you to specify what address to use in
449 the MAIL FROM command. You use it as in this example:
451 require verify = header_sender/callout=mailfrom=abcd@x.y.z
455 (1) As in the case of postmaster_mailfrom (see above), you should think
456 about possible loops.
458 (2) In this case, as in the case of recipient callouts with non-empty
459 senders (the use_sender option), caching is done on the basis of a
460 recipient/sender pair.
462 8. If you build Exim with USE_READLINE=yes in Local/Makefile, it will try to
463 load libreadline dynamically whenever the -be (test expansion) option is
464 used without command line arguments. If successful, it will then use
465 readline() for reading the test data. A line history is supported. By the
466 time Exim does this, it is running as the calling user, so this should not
467 cause any security problems. Security is the reason why this is NOT
468 supported for -bt or -bv, when Exim is running as root or exim,
469 respectively. Note that this option adds to the size of the Exim binary,
470 because the dynamic loading library is not otherwise included. On my
471 desktop it adds about 2.5K. You may need to add -ldl to EXTRA_LIBS when you
472 set USE_READLINE=yes.
474 9. Added ${str2b64:<string>} to the expansion operators. This operator
475 converts an arbitrary string into one that is base64 encoded.
477 10. A new authenticator, called cyrus_sasl, has been added. This requires
478 the presence of the Cyrus SASL library; it authenticates by calling this
479 library, which supports a number of authentication mechanisms, including
480 PLAIN and LOGIN, but also several others that Exim does not support
481 directly. The code for this authenticator was provided by Matthew
482 Byng-Maddick of A L Digital Ltd (http://www.aldigital.co.uk). Here follows
485 xx. THE CYRUS_SASL AUTHENTICATOR
487 The cyrus_sasl authenticator provides server support for the Cyrus library
488 Implementation of the RFC 2222 "Simple Authentication and Security Layer".
489 It provides a gatewaying mechanism directly to the Cyrus interface, so if
490 your Cyrus library can do, for example, CRAM-MD5, then so can the
491 cyrus_sasl authenticator. By default it uses the public name of the driver
492 to determine which mechanism to support.
494 Where access to some kind of secret file is required, for example in GSSAPI
495 or CRAM-MD5, it is worth noting that the authenticator runs as the exim
496 user, and that the Cyrus SASL library has no way of escalating privileges
497 by default. You may also find you need to set environment variables,
498 depending on the driver you are using.
500 xx.1 Using cyrus_sasl as a server
502 The cyrus_sasl authenticator has four private options. It puts the username
503 (on a successful authentication) into $1.
505 server_hostname Type: string* Default: $primary_hostname
507 This option selects the hostname that is used when communicating with
508 the library. It is up to the underlying SASL plug-in what it does with
511 server_mech Type: string Default: public_name
513 This option selects the authentication mechanism this driver should
514 use. It allows you to use a different underlying mechanism from the
515 advertised name. For example:
519 public_name = X-ANYTHING
520 server_mech = CRAM-MD5
523 server_realm Type: string Default: unset
525 This is the SASL realm that the server is claiming to be in.
527 server_service Type: string Default: "smtp"
529 This is the SASL service that the server claims to implement.
531 For straigthforward cases, you do not need to set any of the
532 authenticator's private options. All you need to do is to specify an
533 appropriate mechanism as the public name. Thus, if you have a SASL library
534 that supports CRAM-MD5 and PLAIN, you might have two authenticators as
539 public_name = CRAM-MD5
547 11. There is a new global option called tls_on_connect_ports. Its value must be
548 a list of port numbers; the most common use is expected to be
550 tls_on_connect_ports = 465
552 Setting this option has the same effect as -tls-on-connect on the command
553 line, but only for the specified ports. It applies to all connections, both
554 via the daemon and via inetd. You still need to specify all the ports for
555 the daemon (using daemon_smtp_ports or local_interfaces or the -X command
556 line option) because this option does not add an extra port -- rather, it
557 specifies different behaviour on a port that is defined elsewhere. The
558 -tls-on-connect command line option overrides tls_on_connect_ports, and
559 forces tls-on-connect for all ports.
561 12. There is a new ACL that is run when a DATA command is received, before the
562 data itself is received. The ACL is defined by acl_smtp_predata. (Compare
563 acl_smtp_data, which is run after the data has been received.)
564 This new ACL allows a negative response to be given to the DATA command
565 itself. Header lines added by MAIL or RCPT ACLs are not visible at this
566 time, but any that are defined here are visible when the acl_smtp_data ACL
569 13. The "control=submission" ACL modifier has an option "/domain=xxx" which
570 specifies the domain to be used when creating From: or Sender: lines using
571 the authenticated id as a local part. If the option is supplied with an
572 empty domain, that is, just "/domain=", Exim assumes that the authenticated
573 id is a complete email address, and it uses it as is when creating From:
576 14. It is now possible to make retry rules that apply only when the failing
577 message has a specific sender. In particular, this can be used to define
578 retry rules that apply only to bounce messages. The syntax is to add a new
579 third item to a retry rule, of the form "senders=<address list>". The retry
580 timings themselves then become the fourth item. For example:
582 * * senders=: F,1h,30m
584 would match all bounce messages. If the address list contains white space,
585 it must be enclosed in quotes. For example:
587 a.domain timeout senders="x@b.dom : y@c.dom" G,8h,10m,1.5
589 When testing retry rules using -brt, you can supply a sender using the -f
590 command line option, like this:
592 exim -f "" -brt user@dom.ain
594 If you do not set -f with -brt, a retry rule that contains a senders list
595 will never be matched.
597 15. Two new control modifiers have been added to ACLs: "control = enforce_sync"
598 and "control = no_enforce_sync". This makes it possible to be selective
599 about when SMTP synchronization is enforced. The global option
600 smtp_enforce_sync now specifies the default state of the switch. These
601 controls can appear in any ACL, but the most obvious place to put them is
602 in the ACL defined by acl_smtp_connect, which is run at the start of an
603 incoming SMTP connection, before the first synchronization check.
605 16. Another two new control modifiers are "control = caseful_local_part" and
606 "control = caselower_local_part". These are permitted only in the ACL
607 specified by acl_smtp_rcpt (i.e. during RCPT processing). By default, the
608 contents of $local_part are lower cased before ACL processing.
609 After "control = caseful_local_part", any uppercase letters in the original
610 local part are restored in $local_part for the rest of the ACL, or until
611 "control = caselower_local_part" is encountered. However, this applies only
612 to local part handling that takes place directly in the ACL (for example,
613 as a key in lookups). If a "verify = recipient" test is obeyed, the
614 case-related handling of the local part during the verification is
615 controlled by the router configuration (see the caseful_local_part generic
618 This facility could be used, for example, to add a spam score to local
619 parts containing upper case letters. For example, using $acl_m4 to
620 accumulate the spam score:
622 warn control = caseful_local_part
623 set acl_m4 = ${eval:\
625 ${if match{$local_part}{[A-Z]}{1}{0}}\
627 control = caselower_local_part
629 Notice that we put back the lower cased version afterwards, assuming that
630 is what is wanted for subsequent tests.
632 17. The option hosts_connection_nolog is provided so that certain hosts can be
633 excepted from logging when the +smtp_connection log selector is set. For
634 example, you might want not to log SMTP connections from local processes,
635 or from 127.0.0.1, or from your local LAN. The option is a host list with
636 an unset default. Because it is consulted in the main loop of the daemon,
637 you should strive to restrict its value to a short inline list of IP
638 addresses and networks. To disable logging SMTP connections from local
639 processes, you must create a host list with an empty item. For example:
641 hosts_connection_nolog = :
643 If the +smtp_connection log selector is not set, this option has no effect.
645 18. There is now an acl called acl_smtp_quit, which is run for the QUIT
646 command. The outcome of the ACL does not affect the response code to QUIT,
647 which is always 221. Thus, the ACL does not in fact control any access.
648 For this reason, the only verbs that are permitted are "accept" and "warn".
650 The ACL can be used for tasks such as custom logging at the end of an SMTP
651 session. For example, you can use ACL variables in other ACLs to count
652 messages, recipients, etc., and log the totals at QUIT time using one or
653 more "logwrite" modifiers on a "warn" command.
655 You do not need to have a final "accept", but if you do, you can use a
656 "message" modifier to specify custom text that is sent as part of the 221
659 This ACL is run only for a "normal" QUIT. For certain kinds of disastrous
660 failure (for example, failure to open a log file, or when Exim is bombing
661 out because it has detected an unrecoverable error), all SMTP commands
662 from the client are given temporary error responses until QUIT is received
663 or the connection is closed. In these special cases, the ACL is not run.
665 19. The appendfile transport has two new options, mailbox_size and mailbox_
666 filecount. If either these options are set, it is expanded, and the result
667 is taken as the current size of the mailbox or the number of files in the
668 mailbox, respectively. This makes it possible to use some external means of
669 maintaining the data about the size of a mailbox for enforcing quota
670 limits. The result of expanding these option values must be a decimal
671 number, optionally followed by "K" or "M".
673 20. It seems that there are broken clients in use that cannot handle multiline
674 SMTP responses. Can't people who implement these braindead programs read?
675 RFC 821 mentions multiline responses, and it is over 20 years old. They
676 must handle multiline responses for EHLO, or do they still use HELO?
677 Anyway, here is YAWFAB (yet another workaround for asinine brokenness).
678 There's a new ACL switch that can be set by
680 control = no_multiline_responses
682 If this is set, it suppresses multiline SMTP responses from ACL rejections.
683 One way of doing this would have been just to put out these responses as
684 one long line. However, RFC 2821 specifies a maximum of 512 bytes per
685 response ("use multiline responses for more" it says), and some of the
686 responses might get close to that. So I have implemented this by doing two
689 (1) Extra information that is normally output as part of a rejection
690 caused by sender verification failure is omitted. Only the final line
691 (typically "sender verification failed") is now sent.
693 (2) If a "message" modifier supplies a multiline response, only the first
696 The setting of the switch can, of course, be made conditional on the
699 21. There is now support for the libradius library that comes with FreeBSD.
700 This is an alternative to the radiusclient library that Exim already
701 supports. To use the FreeBSD library, you need to set
703 RADIUS_LIB_TYPE=RADLIB
705 in Local/Makefile, in addition to RADIUS_CONFIGURE_FILE, and you probably
706 also need -libradius in EXTRALIBS.
712 1. The "personal" filter test is brought up-to-date with recommendations from
713 the Sieve specification: (a) The list of non-personal From: addresses now
714 includes "listserv", "majordomo", and "*-request"; (b) If the message
715 contains any header line starting with "List=-" it is treated as
718 2. The Sieve functionality has been extended to support the "copy" and
719 "vacation" extensions, and comparison tests.
721 3. There is now an overall timeout for performing a callout verification. It
722 defaults to 4 times the callout timeout, which applies to individual SMTP
723 commands during the callout. The overall timeout applies when there is more
724 than one host that can be tried. The timeout is checked before trying the
725 next host. This prevents very long delays if there are a large number of
726 hosts and all are timing out (e.g. when the network connections are timing
727 out). The value of the overall timeout can be changed by specifying an
728 additional sub-option for "callout", called "maxwait". For example:
730 verify = sender/callout=5s,maxwait=20s
732 4. Changes to the "personal" filter test:
734 (1) The list of non-personal local parts in From: addresses has been
735 extended to include "listserv", "majordomo", "*-request", and "owner-*",
736 taken from the Sieve specification recommendations.
738 (2) If the message contains any header line starting with "List-" it is
739 treated as non-personal.
741 (3) The test for "circular" in the Subject: header line has been removed
742 because it now seems ill-conceived.
744 5. The autoreply transport has a new option called never_mail. This is an
745 address list. If any run of the transport creates a message with a
746 recipient that matches any item in the list, that recipient is quietly
747 discarded. If all recipients are discarded, no message is created.
753 The documentation is up-to-date for the 4.40 release. What follows here is a
754 brief list of the new features that have been added since 4.30.
756 1. log_incoming_interface affects more log lines.
758 2. New ACL modifier "control = submission".
760 3. CONFIGURE_OWNER can be set at build time to define an alternative owner for
761 the configuration file, in addition to root and exim.
763 4. Added expansion variables $body_zerocount, $recipient_data, and
766 5. The time of last modification of the "new" subdirectory is now used as the
767 "mailbox time last read" when there is a quota error for a maildir
770 6. The special item "+ignore_unknown" may now appear in host lists.
772 7. The special domain-matching patterns @mx_any, @mx_primary, and
773 @mx_secondary can now be followed by "/ignore=<ip list>".
775 8. New expansion conditions: match_domain, match_address, match_local_part,
776 lt, lti, le, lei, gt, gti, ge, and new expansion operators time_interval,
779 9. New lookup type called "iplsearch".
781 10. New log selectors ident_timeout, tls_certificate_verified, queue_time,
782 deliver_time, outgoing_port, return_path_on_delivery.
784 11. New global options smtp_active_hostname and tls_require_ciphers.
786 12. Exinext has -C and -D options.
788 13. "domainlist_cache" forces caching of an apparently variable list.
790 14. For compatibility with Sendmail, the command line option -prval:sval
791 is equivalent to -oMr rval -oMs sval.
793 15. New callout options use_sender and use_postmaster for use when verifying
796 16. John Jetmore's "exipick" utility has been added to the distribution.
798 17. The TLS code now supports CRLs.
800 18. The dnslookup router and the dnsdb lookup type now support the use of SRV
803 19. The redirect router has a new option called qualify_domain.
805 20. exigrep's output now also includes lines that are not related to any
806 particular message, but which do match the pattern.
808 21. New global option write_rejectlog. If it is set false, Exim no longer
809 writes anything to the reject log.