X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/c38d6da94aa327f7c42a90b50508c62702412fef..ea2c01d20f397fb6f7bbaba22ff82ea2ce815907:/doc/doc-txt/NewStuff diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff index b4fda862d..9d0e93993 100644 --- a/doc/doc-txt/NewStuff +++ b/doc/doc-txt/NewStuff @@ -1,816 +1,355 @@ -$Cambridge: exim/doc/doc-txt/NewStuff,v 1.19 2004/11/25 14:31:28 ph10 Exp $ +$Cambridge: exim/doc/doc-txt/NewStuff,v 1.124 2006/12/05 11:35:28 ph10 Exp $ New Features in Exim -------------------- -This file contains descriptions of new features that have been added to Exim, -but have not yet made it into the main manual (which is most conveniently -updated when there is a relatively large batch of changes). The doc/ChangeLog -file contains a listing of all changes, including bug fixes. +This file contains descriptions of new features that have been added to Exim. +Before a formal release, there may be quite a lot of detail so that people can +test from the snapshots or the CVS before the documentation is updated. Once +the documentation is updated, this file is reduced to a short list. -Version 4.44 +Version 4.64 ------------ - 1. There is a new build-time option called CONFIGURE_GROUP which works like - CONFIGURE_OWNER. It specifies one additional group that is permitted for - the runtime configuration file when the group write permission is set. - - 2. The "control=submission" facility has a new option /sender_retain. This - has the effect of setting local_sender_retain true and local_from_check - false for the incoming message in which it is encountered. - - 3. $recipients is now available in the predata ACL (oversight). - - 4. The value of address_data from a sender verification is now available in - $sender_address_data in subsequent conditions in the ACL statement. Note: - this is just like $address_data. The value does not persist after the end - of the current ACL statement. If you want to preserve it, you can use one - of the ACL variables. - - 5. The redirect router has two new options: forbid_sieve_filter and - forbid_exim_filter. When filtering is enabled by allow_filter, these - options control which type(s) of filtering are permitted. By default, both - Exim and Sieve filters are allowed. - - 6. A new option for callouts makes it possible to set a different (usually - smaller) timeout for making the SMTP connection. The keyword is "connect". - For example: - - verify = sender/callout=5s,connect=1s - - If not specified, it defaults to the general timeout value. - - 7. The new variables $sender_verify_failure and $recipient_verify_failure - contain information about exactly what failed. In an ACL, after one of - these failures, the relevant variable contains one of the following words: - - qualify the address was unqualified (no domain), and the message - was neither local nor came from an exempted host; - - route routing failed; - - mail routing succeeded, and a callout was attempted; rejection - occurred at or before the MAIL command (that is, on initial - connection, HELO, or MAIL); - - recipient the RCPT command in a callout was rejected; - - postmaster the postmaster check in a callout was rejected. - - The main use of these variables is expected to be to distinguish between - rejections of MAIL and rejections of RCPT. - - 8. The command line option -dd behaves exactly like -d except when used on a - command that starts a daemon process. In that case, debugging is turned off - for the subprocesses that the daemon creates. Thus, it is useful for - monitoring the behaviour of the daemon without creating as much output as - full debugging. - - 9. $host_address is now set to the target address during the checking of - ignore_target_hosts. - -10. There are four new variables called $spool_space, $log_space, - $spool_inodes, and $log_inodes. The first two contain the amount of free - space in the disk partitions where Exim has its spool directory and log - directory, respectively. (When these are in the same partition, the values - will, of course, be the same.) The second two variables contain the numbers - of free inodes in the respective partitions. - - NOTE: Because disks can nowadays be very large, the values in the space - variables are in kilobytes rather than in bytes. Thus, for example, to - check in an ACL that there is at least 50M free on the spool, you would - write: - - condition = ${if > {$spool_space}{50000}{yes}{no}} - - The values are recalculated whenever any of these variables is referenced. - If the relevant file system does not have the concept of inodes, the value - of those variables is -1. If the operating system does not have the ability - to find the amount of free space (only true for experimental systems), the - space value is -1. - -11. It is now permitted to omit both strings after an "if" condition; if the - condition is true, the result is the string "true". As before, when the - second string is omitted, a false condition yields an empty string. This - makes it less cumbersome to write custom ACL and router conditions. For - example, instead of - - condition = ${if eq {$acl_m4}{1}{yes}{no}} - - or the shorter form - - condition = ${if eq {$acl_m4}{1}{yes}} - - (because the second string has always defaulted to ""), you can now write - - condition = ${if eq {$acl_m4}{1}} - - Previously this was a syntax error. - -12. There is a new "record type" that can be specified in dnsdb lookups. It - is "zns" (for "zone NS"). It performs a lookup for NS records on the given - domain, but if none are found, it removes the first component of the domain - name, and tries again. This process continues until NS records are found - or there are no more components left (or there's a DNS error). In other - words, it may return the name servers for a top-level domain, but it never - returns the root name servers. If there are no NS records for the top-level - domain, the lookup fails. - - For example, ${lookup dnsdb{zns=xxx.quercite.com}} returns the name - servers for quercite.com, whereas ${lookup dnsdb{zns=xxx.edu}} returns - the name servers for edu, assuming in each case that there are no NS - records for the full domain name. - - You should be careful about how you use this lookup because, unless the - top-level domain does not exist, the lookup will always return some host - names. The sort of use to which this might be put is for seeing if the name - servers for a given domain are on a blacklist. You can probably assume that - the name servers for the high-level domains such as .com or .co.uk are not - going to be on such a list. - -13. Another new "record type" is "mxh"; this looks up MX records just as "mx" - does, but it returns only the names of the hosts, omitting the priority - values. - -14. It is now possible to specify a list of domains or IP addresses to be - looked up in a dnsdb lookup. The list is specified in the normal Exim way, - with colon as the default separator, but with the ability to change this. + 1. ACL variables can now be given arbitrary names, as long as they start with + "acl_c" or "acl_m" (for connection variables and message variables), are at + least six characters long, with the sixth character being either a digit or + an underscore. The rest of the name can contain alphanumeric characters and + underscores. This is a compatible change because the old set of variables + such as acl_m12 are a subset of the allowed names. There may now be any + number of ACL variables. For example: + + set acl_c13 = value for original ACL variable + set acl_c13b = whatever + set acl_m_foo = something + + What happens if a syntactically valid but undefined ACL variable is + referenced depends on the setting of the strict_acl_vars option. If it is + false (the default), an empty string is substituted; if it is true, an + error is generated. This affects all ACL variables, including the "old" + ones such as acl_c4. (Previously there wasn't the concept of an undefined + ACL variable.) + + The implementation has been done in such a way that spool files containing + ACL variable settings written by previous releases of Exim are compatible + and can be read by the new release. If only the original numeric names are + used, spool files written by the new release can be read by earlier + releases. + + 2. There is a new ACL modifier called log_reject_target. It makes it possible + to specify which logs are used for messages about ACL rejections. Its + argument is a list of words which can be "main", "reject", or "panic". The + default is "main:reject". The list may be empty, in which case a rejection + is not logged at all. For example, this ACL fragment writes no logging + information when access is denied: + + deny + log_reject_target = + + The modifier can be used in SMTP and non-SMTP ACLs. It applies to both + permanent and temporary rejections. + + 3. There is a new authenticator called "dovecot". This is an interface to the + authentication facility of the Dovecot POP/IMAP server, which can support a + number of authentication methods. If you are using Dovecot to authenticate + POP/IMAP clients, it might be helpful to use the same mechanisms for SMTP + authentication. This is a server authenticator only. The only option is + server_socket, which must specify the socket which is the interface to + Dovecot authentication. The public_name option must specify an + authentication mechanism that Dovecot is configured to support. You can + have several authenticators for different mechanisms. For example: + + dovecot_plain: + driver = dovecot + public_name = PLAIN + server_name = /var/run/dovecot/auth-client + server_setid = $auth1 + + dovecot_ntlm: + driver = dovecot + public_name = NTLM + server_name = /var/run/dovecot/auth-client + server_setid = $auth1 + + If the SMTP connection is encrypted, or if $sender_host_address is equal to + $interface_address (that is, the connection is local), the "secured" option + is passed in the Dovecot authentication command. If, for a TLS connection, + a client certificate has been verified, the "valid-client-cert" option is + passed. + + 4. The variable $message_headers_raw provides a concatenation of all the + messages's headers without any decoding. This is in contrast to + $message_headers, which does RFC2047 decoding on the header contents. + + 5. In a DNS black list, when the facility for restricting the matching IP + values is used, the text from the TXT record that is set in $dnslist_text + may not reflect the true reason for rejection. This happens when lists are + merged and the IP address in the A record is used to distinguish them; + unfortunately there is only one TXT record. One way round this is not to + use merged lists, but that can be inefficient because it requires multiple + DNS lookups where one would do in the vast majority of cases when the host + of interest is not on any of the lists. + + A less inefficient way of solving this problem has now been implemented. If + two domain names, comma-separated, are given, the second is used first to + do an initial check, making use of any IP value restrictions that are set. + If there is a match, the first domain is used, without any IP value + restrictions, to get the TXT record. As a byproduct of this, there is also + a check that the IP being tested is indeed on the first list. The first + domain is the one that is put in $dnslist_domain. For example: + + reject message = rejected because $sender_ip_address is blacklisted \ + at $dnslist_domain\n$dnslist_text + dnslists = sbl.spamhaus.org,sbl-xbl.spamhaus.org=127.0.0.2 : \ + dul.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.10 + + For the first blacklist item, this starts by doing a lookup in + sbl-xbl.spamhaus.org and testing for a 127.0.0.2 return. If there is a + match, it then looks in sbl.spamhaus.org, without checking the return + value, and as long as something is found, it looks for the corresponding + TXT record. If there is no match in sbl-xbl.spamhaus.org, nothing more is + done. The second blacklist item is processed similarly. + + If you are interested in more than one merged list, the same list must be + given several times, but because the results of the DNS lookups are cached, + the DNS calls themselves are not repeated. For example: + + reject dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \ + socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3 : \ + misc.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.4 : \ + dul.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.10 + + In this case there is a lookup in dnsbl.sorbs.net, and if none of the IP + values matches (or if no record is found), this is the only lookup that is + done. Only if there is a match is one of the more specific lists consulted. + + 6. All authenticators now have a server_condition option. Previously, only + plaintext had this, and this has not changed: it must be set to the + authenticator as a server. For the others, if server_condition is set, it + is expanded if authentication is successful, and treated exactly as it is + in plaintext. This can serve as a means of adding authorization to an + authenticator. + + 7. There is a new command-line option called -Mset. It is useful only in + conjunction with -be (that is, when testing string expansions). It must be + followed by a message id; Exim loads the given message from its spool + before doing the expansions, thus setting message-specific variables such + as $message_size and the header variables. The $recipients variable is + available. This feature is provided to make it easier to test expansions + that make use of these variables. However, Exim must be called by an admin + user when -Mset is used. + + 8. Another similar new command-line option is called -bem. It operates like + -be except that it must be followed by the name of a file. For example: + + exim -bem /tmp/testmessage + + The file is read as a message (as if receiving a locally-submitted non-SMTP + message) before any of the test expansions are done. Thus, message-specific + variables such as $message_size and $h_from: are available. However, no + Received: header is added to the message. If the -t option is set, + recipients are read from the headers in the normal way, and are shown in + the $recipients variable. Note that recipients cannot be given on the + command line, because further arguments are taken as strings to expand + (just like -be). + + 9. When an address is delayed because of a 4xx response to a RCPT command, it + is now the combination of sender and recipient that is delayed in + subsequent queue runs until its retry time is reached. You can revert to + the previous behavious, that is, delay the recipient independent of the + sender, by setting address_retry_include_sender=false in the smtp + transport. However, this can lead to problems with servers that regularly + issue 4xx responses to RCPT commands. + +10. Unary negation and the bitwise logical operators and, or, xor, not, and + shift, have been added to the eval: and eval10: expansion items. These + items may now contain arithmetic operators (plus, minus, times, divide, + remainder, negate), bitwise operators (and, or, xor, not, shift), and + parentheses. All operations are carried out using signed integer + arithmetic. Operator priorities are as in C, namely: + + (highest) not, negate + times, divide, remainder + plus, minus + shift-left, shift-right + and + xor + (lowest) or + + Binary operators with the same priority are evaluated from left to right. For example: - ${lookup dnsdb{one.domain.com:two.domain.com}} - ${lookup dnsdb{a=one.host.com:two.host.com}} - ${lookup dnsdb{ptr = <; 1.2.3.4 ; 4.5.6.8}} - - In order to retain backwards compatibility, there is one special case: if - the lookup type is PTR and no change of separator is specified, Exim looks - to see if the rest of the string is precisely one IPv6 address. In this - case, it does not treat it as a list. - - The data from each lookup is concatenated, with newline separators (by - default - see 14 below), in the same way that multiple DNS records for a - single item are handled. - - The dnsdb lookup fails only if all the DNS lookups fail. If there is a - temporary DNS error for any of them, the remaining lookups are still done, - and only if none of them succeed does the dnsdb lookup defer. As long as at - least one of the DNS lookups yields some data, the dnsdb lookup succeeds. - -15. It is now possible to specify the character to be used as a separator when - a dnsdb lookup returns data from more than one DNS record. The default is a - newline. To specify a different character, put '>' followed by the new - character at the start of the query. For example: - - ${lookup dnsdb{>: a=h1.test.ex:h2.test.ex}} - ${lookup dnsdb{>| mxh=<;m1.test.ex;m2.test.ex}} - - It is permitted to specify a space as the separator character. Note that - more than one DNS record can be found for a single lookup item; this - feature is relevant even when you do not specify a list. - - The same effect could be achieved by wrapping the lookup in ${tr...}; this - feature is just a syntactic simplification. - -16. It is now possible to supply a list of domains and/or IP addresses to be - lookup up in a DNS blacklist. Previously, only a single domain name could - be given, for example: - - dnslists = black.list.tld/$sender_host_name - - What follows the slash can now be a list. As with all lists, the default - separator is a colon. However, because this is a sublist within the list of - DNS blacklist domains, it is necessary either to double the separators like - this: - - dnslists = black.list.tld/name.1::name.2 - - or to change the separator character, like this: - - dnslists = black.list.tld/<;name.1;name.2 - - If an item in the list is an IP address, it is inverted before the DNS - blacklist domain is appended. If it is not an IP address, no inversion - occurs. Consider this condition: - - dnslists = black.list.tls/<;192.168.1.2;a.domain - - The DNS lookups that occur are for - - 2.1.168.192.black.list.tld and a.domain.black.list.tld - - Once a DNS record has been found (that matches a specific IP return - address, if specified), no further lookups are done. If there is a - temporary DNS error, the rest of the sublist of domains or IP addresses is - tried. The dnslists item itself defers only if none of the other DNS - lookups in this sublist succeeds. In other words, a successful lookup for - any of the items in the sublist overrides a defer for a previous item. - -17. The log selector queue_time_overall causes Exim to output the time spent on - the queue as an addition to the "Completed" message. Like queue_time (which - puts the queue time on individual delivery lines), the time is tagged with - "QT=", and it is measured from the time that the message starts to be - received, so it includes the reception time. - -18. It is now possible to use both -bF and -bf on the same command, in order to - test a system filter and a user filter in the same run. For example: - - exim -bF /system/filter -bf /user/filter >1} yields 6 + ${eval:0xc<<1} yields 24 + ${eval:~255&0x1234} yields 4608 + ${eval:-(~255&0x1234)} yields -4608 + +11. The variables $interface_address and $interface_port have been renamed + as $received_ip_address and $received_port, to make it clear that they + relate to message reception rather than delivery. (The old names remain + available for compatibility.) + +12. The "message" modifier can now be used on acl verbs to vary the message + that is sent when an SMTP command is accepted. For example, in a RCPT ACL + you could have: + + accept + message = OK, I'll allow you through today + + Previously, this message modifier would have had no effect whatsoever. + + IMPORTANT: The new behaviour applies to "accept" (and "discard") only if + there is no occurrence of "endpass" in the statement. If "endpass" is + present, the behaviour reverts to the old case, where "message" applies to + rejection. This is for backwards compatibility. + + It is always possible to rewrite ACL statements so that "endpass" is not + needed (and indeed it is no longer used in the default configuration, and + is somewhat not recommended nowadays because it causes confusion.) + + It is now generally true that the "message" modifier sets up a text string + that is expanded and used as a response message if the current statement + terminates the ACL. The expansion happens at the time Exim decides that the + ACL is to end, not at the time it processes "message". If the expansion + fails, or generates an empty string, the modifier is ignored. + + For ACLs that are triggered by SMTP commands, the message is returned as + part of the SMTP response. In this situation, the message may begin with an + overriding SMTP response code, optionally followed by an "extended response + code". However, the first digit of the supplied response code must be the + same as would be sent by default. A panic occurs if it is not. For the + predata ACL, note that the default success code is 354, not 2xx. + + However, notwithstanding the previous paragraph, for the QUIT ACL, unlike + the others, the message modifier cannot override the 221 response code. + + In the case of the "connect" ACL, accepting with a message modifier + overrides the value of smtp_banner. + + The ACL test specified by acl_smtp_helo happens when the client issues the + HELO or EHLO commands, after the tests specified by helo_accept_junk_hosts, + helo_allow_chars and helo(_try)_verify_hosts. An acceptance message + modifier for EHLO/HELO may not contain more than one line (it will be + truncated at the first newline and a panic logged), and it cannot affect + the EHLO options. + + + +Version 4.63 ------------ - 1. There is a new Boolean global option called mua_wrapper, defaulting false. - This causes Exim to run an a restricted mode, in order to provide a very - specific service. - - Background: On a personal computer, it is a common requirement for all - email to be sent to a smarthost. There are plenty of MUAs that can be - configured to operate that way, for all the popular operating systems. - However, there are MUAs for Unix-like systems that cannot be so configured: - they submit messages using the command line interface of - /usr/sbin/sendmail. In addition, utility programs such as cron submit - messages this way. - - Requirement: The requirement is for something that can provide the - /usr/sbin/sendmail interface and deliver messages to a smarthost, but not - provide any queueing or retrying facilities. Furthermore, the delivery to - the smarthost should be synchronous, so that if it fails, the sending MUA - is immediately informed. In other words, we want something that in effect - converts a command-line MUA into a TCP/SMTP MUA. - - Solutions: There are a number of applications (for example, ssmtp) that do - this job. However, people have found them to be lacking in various ways. - For instance, some sites want to allow aliasing and forwarding before - sending to the smarthost. - - Using Exim: Exim already had the necessary infrastructure for doing this - job. Just a few tweaks were needed to make it behave as required, though it - is somewhat of an overkill to use a fully-featured MTA for this purpose. - - Setting mua_wrapper=true causes Exim to run in a special mode where it - assumes that it is being used to "wrap" a command-line MUA in the manner - just described. - - If you set mua_wrapper=true, you also need to provide a compatible router - and transport configuration. Typically there will be just one router and - one transport, sending everything to a smarthost. - - When run in MUA wrapping mode, the behaviour of Exim changes in the - following ways: - - (a) A daemon cannot be run, nor will Exim accept incoming messages from - inetd. In other words, the only way to submit messages is via the - command line. - - (b) Each message is synchonously delivered as soon as it is received (-odi - is assumed). All queueing options (queue_only, queue_smtp_domains, - control=queue, control=freeze in an ACL etc.) are quietly ignored. The - Exim reception process does not finish until the delivery attempt is - complete. If the delivery was successful, a zero return code is given. - - (c) Address redirection is permitted, but the final routing for all - addresses must be to the same remote transport, and to the same list of - hosts. Furthermore, the return_address must be the same for all - recipients, as must any added or deleted header lines. In other words, - it must be possible to deliver the message in a single SMTP - transaction, however many recipients there are. - - (d) If the conditions in (c) are not met, or if routing any address results - in a failure or defer status, or if Exim is unable to deliver all the - recipients successfully to one of the hosts immediately, delivery of - the entire message fails. - - (e) Because no queueing is allowed, all failures are treated as permanent; - there is no distinction between 4xx and 5xx SMTP response codes from - the smarthost. Furthermore, because only a single yes/no response can - be given to the caller, it is not possible to deliver to some - recipients and not others. If there is an error (temporary or - permanent) for any recipient, all are failed. - - (f) If more than one host is listed, Exim will try another host after a - connection failure or a timeout, in the normal way. However, if this - kind of failure happens for all the hosts, the delivery fails. - - (g) When delivery fails, an error message is written to the standard error - stream (as well as to Exim's log), and Exim exits to the caller with a - return code value 1. The message is expunged from Exim's spool files. - No bounce messages are ever generated. - - (h) No retry data is maintained, and any retry rules are ignored. - - (i) A number of Exim options are overridden: deliver_drop_privilege is - forced true, max_rcpt in the smtp transport is forced to "unlimited", - remote_max_parallel is forced to one, and fallback hosts are ignored. - - The overall effect is that Exim makes a single synchronous attempt to - deliver the message, failing if there is any kind of problem. Because no - local deliveries are done and no daemon can be run, Exim does not need root - privilege. It should be possible to run it setuid=exim instead of - setuid=root. See section 48.3 in the 4.40 manual for a general discussion - about the advantages and disadvantages of running without root privilege. - - 2. There have been problems with DNS servers when SRV records are looked up. - Some mis-behaving servers return a DNS error or timeout when a non-existent - SRV record is sought. Similar problems have in the past been reported for - MX records. The global dns_again_means_nonexist option can help with this - problem, but it is heavy-handed because it is a global option. There are - now two new options for the dnslookup router. They are called - srv_fail_domains and mx_fail_domains. In each case, the value is a domain - list. If an attempt to look up an SRV or MX record results in a DNS failure - or "try again" response, and the domain matches the relevant list, Exim - behaves as if the DNS had responded "no such record". In the case of an SRV - lookup, this means that the router proceeds to look for MX records; in the - case of an MX lookup, it proceeds to look for A or AAAA records, unless the - domain matches mx_domains. - - 3. The following functions are now available in the local_scan() API: - - (a) void header_remove(int occurrence, uschar *name) - - This function removes header lines. If "occurrence" is zero or negative, - all occurrences of the header are removed. If occurrence is greater - than zero, that particular instance of the header is removed. If no - header(s) can be found that match the specification, the function does - nothing. - - (b) BOOL header_testname(header_line *hdr, uschar *name, int length, - BOOL notdel) - - This function tests whether the given header has the given name. It - is not just a string comparison, because whitespace is permitted - between the name and the colon. If the "notdel" argument is TRUE, a - FALSE return is forced for all "deleted" headers; otherwise they are - not treated specially. For example: - - if (header_testname(h, US"X-Spam", 6, TRUE)) ... - - (c) void header_add_at_position(BOOL after, uschar *name, BOOL topnot, - int type, char *format, ...) - - This function adds a new header line at a specified point in the header - chain. If "name" is NULL, the new header is added at the end of the - chain if "after" is TRUE, or at the start if "after" is FALSE. If - "name" is not NULL, the headers are searched for the first non-deleted - header that matches the name. If one is found, the new header is added - before it if "after" is FALSE. If "after" is true, the new header is - added after the found header and any adjacent subsequent ones with the - same name (even if marked "deleted"). If no matching non-deleted header - is found, the "topnot" option controls where the header is added. If it - is TRUE, addition is at the top; otherwise at the bottom. Thus, to add - a header after all the Received: headers, or at the top if there are no - Received: headers, you could use - - header_add_at_position(TRUE, US"Received", TRUE, ' ', "X-xxx: ..."); - - Normally, there is always at least one non-deleted Received: header, - but there may not be if received_header_text expands to an empty - string. - - (d) BOOL receive_remove_recipient(uschar *recipient) - - This is a convenience function to remove a named recipient from the - list of recipients. It returns TRUE if a recipient was removed, and - FALSE if no matching recipient could be found. The argument must be a - complete email address. - - 4. When an ACL "warn" statement adds one or more header lines to a message, - they are added at the end of the existing header lines by default. It is - now possible to specify that any particular header line should be added - right at the start (before all the Received: lines) or immediately after - the first block of Received: lines in the message. This is done by - specifying :at_start: or :after_received: (or, for completeness, :at_end:) - before the text of the header line. (Header text cannot start with a colon, - as there has to be a header name first.) For example: - - warn message = :after_received:X-My-Header: something or other... - - If more than one header is supplied in a single warn statement, each one is - treated independently and can therefore be placed differently. If you add - more than one line at the start, or after the Received: block, they will - end up in reverse order. - - Warning: This facility currently applies only to header lines that are - added in an ACL. It does NOT work for header lines that are added in a - system filter or in a router or transport. - - 5. There is now a new error code that can be used in retry rules. Its name is - "rcpt_4xx", and there are three forms. A literal "rcpt_4xx" matches any 4xx - error received for an outgoing SMTP RCPT command; alternatively, either the - first or both of the x's can be given as digits, for example: "rcpt_45x" or - "rcpt_436". If you want (say) to recognize 452 errors given to RCPT - commands by a particular host, and have only a one-hour retry for them, you - can set up a retry rule of this form: - - the.host.name rcpt_452 F,1h,10m - - Naturally, this rule must come before any others that would match. - - These new errors apply to both outgoing SMTP (the smtp transport) and - outgoing LMTP (either the lmtp transport, or the smtp transport in LMTP - mode). Note, however, that they apply only to responses to RCPT commands. - - 6. The "postmaster" option of the callout feature of address verification has - been extended to make it possible to use a non-empty MAIL FROM address when - checking a postmaster address. The new suboption is called "postmaster_ - mailfrom", and you use it like this: - - require verify = sender/callout=postmaster_mailfrom=abc@x.y.z - - Providing this suboption causes the postmaster check to be done using the - given address. The original "postmaster" option is equivalent to - - require verify = sender/callout=postmaster_mailfrom= - - If both suboptions are present, the rightmost one overrides. - - Important notes: - - (1) If you use a non-empty sender address for postmaster checking, there is - the likelihood that the remote host will itself initiate a callout - check back to your host to check that address. As this is a "normal" - callout check, the sender will most probably be empty, thus avoiding - possible callout loops. However, to be on the safe side it would be - best to set up your own ACLs so that they do not do sender verification - checks when the recipient is the address you use for postmaster callout - checking. - - (2) The caching arrangements for postmaster checking do NOT take account of - the sender address. It is assumed that either the empty address, or a - fixed non-empty address will be used. All that Exim remembers is that - the postmaster check for the domain succeeded or failed. - - 7. When verifying addresses in header lines using the verify=header_sender - option, Exim behaves by default as if the addresses are envelope sender - addresses from a message. Callout verification therefore tests to see - whether a bounce message could be delivered, by using an empty address in - the MAIL FROM command. However, it is arguable that these addresses might - never be used as envelope senders, and could therefore justifiably reject - bounce messages (empty senders). There is now an additional callout option - for verify=header_sender that allows you to specify what address to use in - the MAIL FROM command. You use it as in this example: - - require verify = header_sender/callout=mailfrom=abcd@x.y.z - - Important notes: - - (1) As in the case of postmaster_mailfrom (see above), you should think - about possible loops. - - (2) In this case, as in the case of recipient callouts with non-empty - senders (the use_sender option), caching is done on the basis of a - recipient/sender pair. - - 8. If you build Exim with USE_READLINE=yes in Local/Makefile, it will try to - load libreadline dynamically whenever the -be (test expansion) option is - used without command line arguments. If successful, it will then use - readline() for reading the test data. A line history is supported. By the - time Exim does this, it is running as the calling user, so this should not - cause any security problems. Security is the reason why this is NOT - supported for -bt or -bv, when Exim is running as root or exim, - respectively. Note that this option adds to the size of the Exim binary, - because the dynamic loading library is not otherwise included. On my - desktop it adds about 2.5K. You may need to add -ldl to EXTRA_LIBS when you - set USE_READLINE=yes. - - 9. Added ${str2b64:} to the expansion operators. This operator - converts an arbitrary string into one that is base64 encoded. - -10. A new authenticator, called cyrus_sasl, has been added. This requires - the presence of the Cyrus SASL library; it authenticates by calling this - library, which supports a number of authentication mechanisms, including - PLAIN and LOGIN, but also several others that Exim does not support - directly. The code for this authenticator was provided by Matthew - Byng-Maddick of A L Digital Ltd (http://www.aldigital.co.uk). Here follows - draft documentation: - - xx. THE CYRUS_SASL AUTHENTICATOR - - The cyrus_sasl authenticator provides server support for the Cyrus library - Implementation of the RFC 2222 "Simple Authentication and Security Layer". - It provides a gatewaying mechanism directly to the Cyrus interface, so if - your Cyrus library can do, for example, CRAM-MD5, then so can the - cyrus_sasl authenticator. By default it uses the public name of the driver - to determine which mechanism to support. - - Where access to some kind of secret file is required, for example in GSSAPI - or CRAM-MD5, it is worth noting that the authenticator runs as the exim - user, and that the Cyrus SASL library has no way of escalating privileges - by default. You may also find you need to set environment variables, - depending on the driver you are using. - - xx.1 Using cyrus_sasl as a server - - The cyrus_sasl authenticator has four private options. It puts the username - (on a successful authentication) into $1. - - server_hostname Type: string* Default: $primary_hostname - - This option selects the hostname that is used when communicating with - the library. It is up to the underlying SASL plug-in what it does with - this data. - - server_mech Type: string Default: public_name - - This option selects the authentication mechanism this driver should - use. It allows you to use a different underlying mechanism from the - advertised name. For example: - - sasl: - driver = cyrus_sasl - public_name = X-ANYTHING - server_mech = CRAM-MD5 - server_set_id = $1 - - server_realm Type: string Default: unset - - This is the SASL realm that the server is claiming to be in. - - server_service Type: string Default: "smtp" - - This is the SASL service that the server claims to implement. - - For straigthforward cases, you do not need to set any of the - authenticator's private options. All you need to do is to specify an - appropriate mechanism as the public name. Thus, if you have a SASL library - that supports CRAM-MD5 and PLAIN, you might have two authenticators as - follows: - - sasl_cram_md5: - driver = cyrus_sasl - public_name = CRAM-MD5 - server_set_id = $1 - - sasl_plain: - driver = cyrus_sasl - public_name = PLAIN - server_set_id = $1 - -11. There is a new global option called tls_on_connect_ports. Its value must be - a list of port numbers; the most common use is expected to be - - tls_on_connect_ports = 465 - - Setting this option has the same effect as -tls-on-connect on the command - line, but only for the specified ports. It applies to all connections, both - via the daemon and via inetd. You still need to specify all the ports for - the daemon (using daemon_smtp_ports or local_interfaces or the -X command - line option) because this option does not add an extra port -- rather, it - specifies different behaviour on a port that is defined elsewhere. The - -tls-on-connect command line option overrides tls_on_connect_ports, and - forces tls-on-connect for all ports. - -12. There is a new ACL that is run when a DATA command is received, before the - data itself is received. The ACL is defined by acl_smtp_predata. (Compare - acl_smtp_data, which is run after the data has been received.) - This new ACL allows a negative response to be given to the DATA command - itself. Header lines added by MAIL or RCPT ACLs are not visible at this - time, but any that are defined here are visible when the acl_smtp_data ACL - is run. - -13. The "control=submission" ACL modifier has an option "/domain=xxx" which - specifies the domain to be used when creating From: or Sender: lines using - the authenticated id as a local part. If the option is supplied with an - empty domain, that is, just "/domain=", Exim assumes that the authenticated - id is a complete email address, and it uses it as is when creating From: - or Sender: lines. - -14. It is now possible to make retry rules that apply only when the failing - message has a specific sender. In particular, this can be used to define - retry rules that apply only to bounce messages. The syntax is to add a new - third item to a retry rule, of the form "senders=
". The retry - timings themselves then become the fourth item. For example: - - * * senders=: F,1h,30m - - would match all bounce messages. If the address list contains white space, - it must be enclosed in quotes. For example: - - a.domain timeout senders="x@b.dom : y@c.dom" G,8h,10m,1.5 - - When testing retry rules using -brt, you can supply a sender using the -f - command line option, like this: - - exim -f "" -brt user@dom.ain - - If you do not set -f with -brt, a retry rule that contains a senders list - will never be matched. - -15. Two new control modifiers have been added to ACLs: "control = enforce_sync" - and "control = no_enforce_sync". This makes it possible to be selective - about when SMTP synchronization is enforced. The global option - smtp_enforce_sync now specifies the default state of the switch. These - controls can appear in any ACL, but the most obvious place to put them is - in the ACL defined by acl_smtp_connect, which is run at the start of an - incoming SMTP connection, before the first synchronization check. - -16. Another two new control modifiers are "control = caseful_local_part" and - "control = caselower_local_part". These are permitted only in the ACL - specified by acl_smtp_rcpt (i.e. during RCPT processing). By default, the - contents of $local_part are lower cased before ACL processing. - After "control = caseful_local_part", any uppercase letters in the original - local part are restored in $local_part for the rest of the ACL, or until - "control = caselower_local_part" is encountered. However, this applies only - to local part handling that takes place directly in the ACL (for example, - as a key in lookups). If a "verify = recipient" test is obeyed, the - case-related handling of the local part during the verification is - controlled by the router configuration (see the caseful_local_part generic - router option). - - This facility could be used, for example, to add a spam score to local - parts containing upper case letters. For example, using $acl_m4 to - accumulate the spam score: - - warn control = caseful_local_part - set acl_m4 = ${eval:\ - $acl_m4 + \ - ${if match{$local_part}{[A-Z]}{1}{0}}\ - } - control = caselower_local_part - - Notice that we put back the lower cased version afterwards, assuming that - is what is wanted for subsequent tests. - -17. The option hosts_connection_nolog is provided so that certain hosts can be - excepted from logging when the +smtp_connection log selector is set. For - example, you might want not to log SMTP connections from local processes, - or from 127.0.0.1, or from your local LAN. The option is a host list with - an unset default. Because it is consulted in the main loop of the daemon, - you should strive to restrict its value to a short inline list of IP - addresses and networks. To disable logging SMTP connections from local - processes, you must create a host list with an empty item. For example: - - hosts_connection_nolog = : - - If the +smtp_connection log selector is not set, this option has no effect. - -18. There is now an acl called acl_smtp_quit, which is run for the QUIT - command. The outcome of the ACL does not affect the response code to QUIT, - which is always 221. Thus, the ACL does not in fact control any access. - For this reason, the only verbs that are permitted are "accept" and "warn". - - The ACL can be used for tasks such as custom logging at the end of an SMTP - session. For example, you can use ACL variables in other ACLs to count - messages, recipients, etc., and log the totals at QUIT time using one or - more "logwrite" modifiers on a "warn" command. - - You do not need to have a final "accept", but if you do, you can use a - "message" modifier to specify custom text that is sent as part of the 221 - response. - - This ACL is run only for a "normal" QUIT. For certain kinds of disastrous - failure (for example, failure to open a log file, or when Exim is bombing - out because it has detected an unrecoverable error), all SMTP commands - from the client are given temporary error responses until QUIT is received - or the connection is closed. In these special cases, the ACL is not run. - -19. The appendfile transport has two new options, mailbox_size and mailbox_ - filecount. If either these options are set, it is expanded, and the result - is taken as the current size of the mailbox or the number of files in the - mailbox, respectively. This makes it possible to use some external means of - maintaining the data about the size of a mailbox for enforcing quota - limits. The result of expanding these option values must be a decimal - number, optionally followed by "K" or "M". - -20. It seems that there are broken clients in use that cannot handle multiline - SMTP responses. Can't people who implement these braindead programs read? - RFC 821 mentions multiline responses, and it is over 20 years old. They - must handle multiline responses for EHLO, or do they still use HELO? - Anyway, here is YAWFAB (yet another workaround for asinine brokenness). - There's a new ACL switch that can be set by - - control = no_multiline_responses - - If this is set, it suppresses multiline SMTP responses from ACL rejections. - One way of doing this would have been just to put out these responses as - one long line. However, RFC 2821 specifies a maximum of 512 bytes per - response ("use multiline responses for more" it says), and some of the - responses might get close to that. So I have implemented this by doing two - very easy things: - - (1) Extra information that is normally output as part of a rejection - caused by sender verification failure is omitted. Only the final line - (typically "sender verification failed") is now sent. - - (2) If a "message" modifier supplies a multiline response, only the first - line is output. - - The setting of the switch can, of course, be made conditional on the - calling host. - -21. There is now support for the libradius library that comes with FreeBSD. - This is an alternative to the radiusclient library that Exim already - supports. To use the FreeBSD library, you need to set - - RADIUS_LIB_TYPE=RADLIB - - in Local/Makefile, in addition to RADIUS_CONFIGURE_FILE, and you probably - also need -libradius in EXTRALIBS. - - -Version 4.42 +1. There is a new Boolean option called filter_prepend_home for the redirect + router. + +2. There is a new acl, set by acl_not_smtp_start, which is run right at the + start of receiving a non-SMTP message, before any of the message has been + read. + +3. When an SMTP error message is specified in a "message" modifier in an ACL, + or in a :fail: or :defer: message in a redirect router, Exim now checks the + start of the message for an SMTP error code. + +4. There is a new parameter for LDAP lookups called "referrals", which takes + one of the settings "follow" (the default) or "nofollow". + +5. Version 20070721.2 of exipick now included, offering these new options: + --reverse + After all other sorting options have bee processed, reverse order + before displaying messages (-R is synonym). + --random + Randomize order of matching messages before displaying. + --size + Instead of displaying the matching messages, display the sum + of their sizes. + --sort [,...] + Before displaying matching messages, sort the messages according to + each messages value for each variable. + --not + Negate the value for every test (returns inverse output from the + same criteria without --not). + + +Version 4.62 ------------ - 1. The "personal" filter test is brought up-to-date with recommendations from - the Sieve specification: (a) The list of non-personal From: addresses now - includes "listserv", "majordomo", and "*-request"; (b) If the message - contains any header line starting with "List=-" it is treated as - non-personal. - - 2. The Sieve functionality has been extended to support the "copy" and - "vacation" extensions, and comparison tests. - - 3. There is now an overall timeout for performing a callout verification. It - defaults to 4 times the callout timeout, which applies to individual SMTP - commands during the callout. The overall timeout applies when there is more - than one host that can be tried. The timeout is checked before trying the - next host. This prevents very long delays if there are a large number of - hosts and all are timing out (e.g. when the network connections are timing - out). The value of the overall timeout can be changed by specifying an - additional sub-option for "callout", called "maxwait". For example: - - verify = sender/callout=5s,maxwait=20s +1. The ${readsocket expansion item now supports Internet domain sockets as well + as Unix domain sockets. If the first argument begins "inet:", it must be of + the form "inet:host:port". The port is mandatory; it may be a number or the + name of a TCP port in /etc/services. The host may be a name, or it may be an + IP address. An ip address may optionally be enclosed in square brackets. + This is best for IPv6 addresses. For example: - 4. Changes to the "personal" filter test: + ${readsocket{inet:[::1]:1234}{}... - (1) The list of non-personal local parts in From: addresses has been - extended to include "listserv", "majordomo", "*-request", and "owner-*", - taken from the Sieve specification recommendations. + Only a single host name may be given, but if looking it up yield more than + one IP address, they are each tried in turn until a connection is made. Once + a connection has been made, the behaviour is as for ${readsocket with a Unix + domain socket. - (2) If the message contains any header line starting with "List-" it is - treated as non-personal. +2. If a redirect router sets up file or pipe deliveries for more than one + incoming address, and the relevant transport has batch_max set greater than + one, a batch delivery now occurs. - (3) The test for "circular" in the Subject: header line has been removed - because it now seems ill-conceived. +3. The appendfile transport has a new option called maildirfolder_create_regex. + Its value is a regular expression. For a maildir delivery, this is matched + against the maildir directory; if it matches, Exim ensures that a + maildirfolder file is created alongside the new, cur, and tmp directories. - 5. The autoreply transport has a new option called never_mail. This is an - address list. If any run of the transport creates a message with a - recipient that matches any item in the list, that recipient is quietly - discarded. If all recipients are discarded, no message is created. - -Version 4.40 +Version 4.61 ------------ -The documentation is up-to-date for the 4.40 release. What follows here is a -brief list of the new features that have been added since 4.30. - - 1. log_incoming_interface affects more log lines. +The documentation is up-to-date for the 4.61 release. Major new features since +the 4.60 release are: - 2. New ACL modifier "control = submission". +. An option called disable_ipv6, to disable the use of IPv6 completely. - 3. CONFIGURE_OWNER can be set at build time to define an alternative owner for - the configuration file, in addition to root and exim. +. An increase in the number of ACL variables to 20 of each type. - 4. Added expansion variables $body_zerocount, $recipient_data, and - $sender_data. +. A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1, + $2, $3, (though those are still set) because the numeric variables get used + for other things in complicated expansions. - 5. The time of last modification of the "new" subdirectory is now used as the - "mailbox time last read" when there is a quota error for a maildir - delivery. +. The default for rfc1413_query_timeout has been changed from 30s to 5s. - 6. The special item "+ignore_unknown" may now appear in host lists. +. It is possible to use setclassresources() on some BSD OS to control the + resources used in pipe deliveries. - 7. The special domain-matching patterns @mx_any, @mx_primary, and - @mx_secondary can now be followed by "/ignore=". +. A new ACL modifier called add_header, which can be used with any verb. - 8. New expansion conditions: match_domain, match_address, match_local_part, - lt, lti, le, lei, gt, gti, ge, and new expansion operators time_interval, - eval10, and base62d. +. More errors are detectable in retry rules. - 9. New lookup type called "iplsearch". +There are a number of other additions too. -10. New log selectors ident_timeout, tls_certificate_verified, queue_time, - deliver_time, outgoing_port, return_path_on_delivery. -11. New global options smtp_active_hostname and tls_require_ciphers. - -12. Exinext has -C and -D options. +Version 4.60 +------------ -13. "domainlist_cache" forces caching of an apparently variable list. +The documentation is up-to-date for the 4.60 release. Major new features since +the 4.50 release are: -14. For compatibility with Sendmail, the command line option -prval:sval - is equivalent to -oMr rval -oMs sval. +. Support for SQLite. -15. New callout options use_sender and use_postmaster for use when verifying - recipients. +. Support for IGNOREQUOTA in LMTP. -16. John Jetmore's "exipick" utility has been added to the distribution. +. Extensions to the "submission mode" features. -17. The TLS code now supports CRLs. +. Support for Client SMTP Authorization (CSA). -18. The dnslookup router and the dnsdb lookup type now support the use of SRV - records. +. Support for ratelimiting hosts and users. -19. The redirect router has a new option called qualify_domain. +. New expansion items to help with the BATV "prvs" scheme. -20. exigrep's output now also includes lines that are not related to any - particular message, but which do match the pattern. +. A "match_ip" condition, that matches an IP address against a list. -21. New global option write_rejectlog. If it is set false, Exim no longer - writes anything to the reject log. +There are many more minor changes. ****