X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/5abeaa6ed041be7701397e36ceed5379ac356998..48c7f9e2e3b50cd5548447de62c77c7ddfe21519:/doc/doc-txt/NewStuff diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff index 7f00ee5cd..695acce86 100644 --- a/doc/doc-txt/NewStuff +++ b/doc/doc-txt/NewStuff @@ -1,52 +1,185 @@ -$Cambridge: exim/doc/doc-txt/NewStuff,v 1.108 2006/07/31 14:19:31 ph10 Exp $ +$Cambridge: exim/doc/doc-txt/NewStuff,v 1.120 2006/11/06 15:50:12 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 4.64 +------------ + +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. + + Version 4.63 ------------ 1. There is a new Boolean option called filter_prepend_home for the redirect - router. It defaults true, for backward compatibility. If a "save" command in - an Exim filter has a relative path for its argument, and $home is defined, - it is automatically prepended to the relative path. This action can now be - prevented by setting filter_prepend_home false. + 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. (This is the analogue of the acl_smtp_predata ACL for SMTP input.) The - result of this ACL is ignored; it cannot be used to reject a message. If - you really need to, you could set a value in an ACL variable here and reject - based on that in the acl_not_smtp ACL. However, this ACL can be used to set - controls, and in particular, it can be used to set control=suppress_local_ - fixups, which cannot be used in the acl_not_smtp ACL because by the time - that ACL is run, it is too late. When the acl_not_smtp_start ACL is run, the - sender and recipients are known, so the "senders" and "sender_domains" - conditions and $sender_address and $recipients variables can be used. - Variables such as $authenticated_ sender are also available. It is possible - to specify added header lines in this ACL. + 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. This consists of three digits - followed by a space, optionally followed by an extended code of the form - n.n.n, also followed by a space. If this is the case and the very first - digit is the same as the default error code, the code from the message is - used instead. If the very first digit is incorrect, a panic error is logged, - and the default code is used. This is an incompatible change, but it is not - expected to affect many (if any) configurations. It is possible to suppress - the use of the supplied code in a redirect router by setting the - forbid_smtp_code option true. In this case, any SMTP code is quietly - ignored. + 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". The latter stops - the LDAP library from trying to follow referrals issued by the LDAP server. + one of the settings "follow" (the default) or "nofollow". 5. Version 20070721.2 of exipick now included, offering these new options: --reverse