| 1 | $Cambridge: exim/doc/doc-txt/NewStuff,v 1.119 2006/10/24 12:56:06 ph10 Exp $ |
| 2 | |
| 3 | New Features in Exim |
| 4 | -------------------- |
| 5 | |
| 6 | This file contains descriptions of new features that have been added to Exim. |
| 7 | Before a formal release, there may be quite a lot of detail so that people can |
| 8 | test from the snapshots or the CVS before the documentation is updated. Once |
| 9 | the documentation is updated, this file is reduced to a short list. |
| 10 | |
| 11 | |
| 12 | Version 4.64 |
| 13 | ------------ |
| 14 | |
| 15 | 1. ACL variables can now be given arbitrary names, as long as they start with |
| 16 | "acl_c" or "acl_m" (for connection variables and message variables), are |
| 17 | at least six characters long, with the sixth character being either a digit |
| 18 | or an underscore. The rest of the name can contain alphanumeric characters |
| 19 | and underscores. This is a compatible change because the old set of |
| 20 | variables such as acl_m12 are a subset of the allowed names. There may now |
| 21 | be any number of ACL variables. For example: |
| 22 | |
| 23 | set acl_c13 = value for original ACL variable |
| 24 | set acl_c13b = whatever |
| 25 | set acl_m_foo = something |
| 26 | |
| 27 | What happens if a syntactically valid but undefined ACL variable is |
| 28 | referenced depends on the setting of the strict_acl_vars option. If it is |
| 29 | false (the default), an empty string is substituted; if it is true, an error |
| 30 | is generated. This affects all ACL variables, including the "old" ones such |
| 31 | as acl_c4. (Previously there wasn't the concept of an undefined ACL |
| 32 | variable.) |
| 33 | |
| 34 | The implementation has been done in such a way that spool files containing |
| 35 | ACL variable settings written by previous releases of Exim are compatible |
| 36 | and can be read by the new release. If only the original numeric names are |
| 37 | used, spool files written by the new release can be read by earlier |
| 38 | releases. |
| 39 | |
| 40 | 2. There is a new ACL modifier called log_reject_target. It makes it possible |
| 41 | to specify which logs are used for messages about ACL rejections. Its |
| 42 | argument is a list of words which can be "main", "reject", or "panic". The |
| 43 | default is "main:reject". The list may be empty, in which case a rejection |
| 44 | is not logged at all. For example, this ACL fragment writes no logging |
| 45 | information when access is denied: |
| 46 | |
| 47 | deny <some conditions> |
| 48 | log_reject_target = |
| 49 | |
| 50 | The modifier can be used in SMTP and non-SMTP ACLs. It applies to both |
| 51 | permanent and temporary rejections. |
| 52 | |
| 53 | 3. There is a new authenticator called "dovecot". This is an interface to the |
| 54 | authentication facility of the Dovecot POP/IMAP server, which can support a |
| 55 | number of authentication methods. If you are using Dovecot to authenticate |
| 56 | POP/IMAP clients, it might be helpful to use the same mechanisms for SMTP |
| 57 | authentication. This is a server authenticator only. The only option is |
| 58 | server_socket, which must specify the socket which is the interface to |
| 59 | Dovecot authentication. The public_name option must specify an |
| 60 | authentication mechanism that Dovecot is configured to support. You can have |
| 61 | several authenticators for different mechanisms. For example: |
| 62 | |
| 63 | dovecot_plain: |
| 64 | driver = dovecot |
| 65 | public_name = PLAIN |
| 66 | server_name = /var/run/dovecot/auth-client |
| 67 | server_setid = $auth1 |
| 68 | |
| 69 | dovecot_ntlm: |
| 70 | driver = dovecot |
| 71 | public_name = NTLM |
| 72 | server_name = /var/run/dovecot/auth-client |
| 73 | server_setid = $auth1 |
| 74 | |
| 75 | If the SMTP connection is encrypted, or if $sender_host_address is equal to |
| 76 | $interface_address (that is, the connection is local), the "secured" option |
| 77 | is passed in the Dovecot authentication command. If, for a TLS connection, a |
| 78 | client certificate has been verified, the "valid-client-cert" option is |
| 79 | passed. |
| 80 | |
| 81 | 4. The variable $message_headers_raw provides a concatenation of all the |
| 82 | messages's headers without any decoding. This is in contrast to |
| 83 | $message_headers, which does RFC2047 decoding on the header contents. |
| 84 | |
| 85 | 5. In a DNS black list, when the facility for restricting the matching IP |
| 86 | values is used, the text from the TXT record that is set in $dnslist_text |
| 87 | may not reflect the true reason for rejection. This happens when lists are |
| 88 | merged and the IP address in the A record is used to distinguish them; |
| 89 | unfortunately there is only one TXT record. One way round this is not to use |
| 90 | merged lists, but that can be inefficient because it requires multiple DNS |
| 91 | lookups where one would do in the vast majority of cases when the host of |
| 92 | interest is not on any of the lists. |
| 93 | |
| 94 | A less inefficient way of solving this problem has now been implemented. If |
| 95 | two domain names, comma-separated, are given, the second is used first to do |
| 96 | an initial check, making use of any IP value restrictions that are set. If |
| 97 | there is a match, the first domain is used, without any IP value |
| 98 | restrictions, to get the TXT record. As a byproduct of this, there is also a |
| 99 | check that the IP being tested is indeed on the first list. The first domain |
| 100 | is the one that is put in $dnslist_domain. For example: |
| 101 | |
| 102 | reject message = rejected because $sender_ip_address is blacklisted \ |
| 103 | at $dnslist_domain\n$dnslist_text |
| 104 | dnslists = sbl.spamhaus.org,sbl-xbl.spamhaus.org=127.0.0.2 : \ |
| 105 | dul.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.10 |
| 106 | |
| 107 | For the first blacklist item, this starts by doing a lookup in |
| 108 | sbl-xbl.spamhaus.org and testing for a 127.0.0.2 return. If there is a |
| 109 | match, it then looks in sbl.spamhaus.org, without checking the return value, |
| 110 | and as long as something is found, it looks for the corresponding TXT |
| 111 | record. If there is no match in sbl-xbl.spamhaus.org, nothing more is done. |
| 112 | The second blacklist item is processed similarly. |
| 113 | |
| 114 | If you are interested in more than one merged list, the same list must be |
| 115 | given several times, but because the results of the DNS lookups are cached, |
| 116 | the DNS calls themselves are not repeated. For example: |
| 117 | |
| 118 | reject dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \ |
| 119 | socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3 : \ |
| 120 | misc.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.4 : \ |
| 121 | dul.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.10 |
| 122 | |
| 123 | In this case there is a lookup in dnsbl.sorbs.net, and if none of the IP |
| 124 | values matches (or if no record is found), this is the only lookup that is |
| 125 | done. Only if there is a match is one of the more specific lists consulted. |
| 126 | |
| 127 | 6. All authenticators now have a server_condition option. Previously, only |
| 128 | plaintext had this, and this has not changed: it must be set to the |
| 129 | authenticator as a server. For the others, if server_condition is set, it is |
| 130 | expanded if authentication is successful, and treated exactly as it is in |
| 131 | plaintext. This can serve as a means of adding authorization to an |
| 132 | authenticator. |
| 133 | |
| 134 | 7. There is a new command-line option called -Mset. It is useful only in |
| 135 | conjunction with -be (that is, when testing string expansions). It must be |
| 136 | followed by a message id; Exim loads the given message from its spool before |
| 137 | doing the expansions, thus setting message-specific variables such as |
| 138 | $message_size and the header variables. The $recipients variable is |
| 139 | available. This feature is provided to make it easier to test expansions |
| 140 | that make use of these variables. However, Exim must be called by an admin |
| 141 | user when -Mset is used. |
| 142 | |
| 143 | 8. Another similar new command-line option is called -bem. It operates like -be |
| 144 | except that it must be followed by the name of a file. For example: |
| 145 | |
| 146 | exim -bem /tmp/testmessage |
| 147 | |
| 148 | The file is read as a message (as if receiving a locally-submitted non-SMTP |
| 149 | message) before any of the test expansions are done. Thus, message-specific |
| 150 | variables such as $message_size and $h_from: are available. However, no |
| 151 | Received: header is added to the message. If the -t option is set, |
| 152 | recipients are read from the headers in the normal way, and are shown in the |
| 153 | $recipients variable. Note that recipients cannot be given on the command |
| 154 | line, because further arguments are taken as strings to expand (just like |
| 155 | -be). |
| 156 | |
| 157 | |
| 158 | Version 4.63 |
| 159 | ------------ |
| 160 | |
| 161 | 1. There is a new Boolean option called filter_prepend_home for the redirect |
| 162 | router. |
| 163 | |
| 164 | 2. There is a new acl, set by acl_not_smtp_start, which is run right at the |
| 165 | start of receiving a non-SMTP message, before any of the message has been |
| 166 | read. |
| 167 | |
| 168 | 3. When an SMTP error message is specified in a "message" modifier in an ACL, |
| 169 | or in a :fail: or :defer: message in a redirect router, Exim now checks the |
| 170 | start of the message for an SMTP error code. |
| 171 | |
| 172 | 4. There is a new parameter for LDAP lookups called "referrals", which takes |
| 173 | one of the settings "follow" (the default) or "nofollow". |
| 174 | |
| 175 | 5. Version 20070721.2 of exipick now included, offering these new options: |
| 176 | --reverse |
| 177 | After all other sorting options have bee processed, reverse order |
| 178 | before displaying messages (-R is synonym). |
| 179 | --random |
| 180 | Randomize order of matching messages before displaying. |
| 181 | --size |
| 182 | Instead of displaying the matching messages, display the sum |
| 183 | of their sizes. |
| 184 | --sort <variable>[,<variable>...] |
| 185 | Before displaying matching messages, sort the messages according to |
| 186 | each messages value for each variable. |
| 187 | --not |
| 188 | Negate the value for every test (returns inverse output from the |
| 189 | same criteria without --not). |
| 190 | |
| 191 | |
| 192 | Version 4.62 |
| 193 | ------------ |
| 194 | |
| 195 | 1. The ${readsocket expansion item now supports Internet domain sockets as well |
| 196 | as Unix domain sockets. If the first argument begins "inet:", it must be of |
| 197 | the form "inet:host:port". The port is mandatory; it may be a number or the |
| 198 | name of a TCP port in /etc/services. The host may be a name, or it may be an |
| 199 | IP address. An ip address may optionally be enclosed in square brackets. |
| 200 | This is best for IPv6 addresses. For example: |
| 201 | |
| 202 | ${readsocket{inet:[::1]:1234}{<request data>}... |
| 203 | |
| 204 | Only a single host name may be given, but if looking it up yield more than |
| 205 | one IP address, they are each tried in turn until a connection is made. Once |
| 206 | a connection has been made, the behaviour is as for ${readsocket with a Unix |
| 207 | domain socket. |
| 208 | |
| 209 | 2. If a redirect router sets up file or pipe deliveries for more than one |
| 210 | incoming address, and the relevant transport has batch_max set greater than |
| 211 | one, a batch delivery now occurs. |
| 212 | |
| 213 | 3. The appendfile transport has a new option called maildirfolder_create_regex. |
| 214 | Its value is a regular expression. For a maildir delivery, this is matched |
| 215 | against the maildir directory; if it matches, Exim ensures that a |
| 216 | maildirfolder file is created alongside the new, cur, and tmp directories. |
| 217 | |
| 218 | |
| 219 | Version 4.61 |
| 220 | ------------ |
| 221 | |
| 222 | The documentation is up-to-date for the 4.61 release. Major new features since |
| 223 | the 4.60 release are: |
| 224 | |
| 225 | . An option called disable_ipv6, to disable the use of IPv6 completely. |
| 226 | |
| 227 | . An increase in the number of ACL variables to 20 of each type. |
| 228 | |
| 229 | . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1, |
| 230 | $2, $3, (though those are still set) because the numeric variables get used |
| 231 | for other things in complicated expansions. |
| 232 | |
| 233 | . The default for rfc1413_query_timeout has been changed from 30s to 5s. |
| 234 | |
| 235 | . It is possible to use setclassresources() on some BSD OS to control the |
| 236 | resources used in pipe deliveries. |
| 237 | |
| 238 | . A new ACL modifier called add_header, which can be used with any verb. |
| 239 | |
| 240 | . More errors are detectable in retry rules. |
| 241 | |
| 242 | There are a number of other additions too. |
| 243 | |
| 244 | |
| 245 | Version 4.60 |
| 246 | ------------ |
| 247 | |
| 248 | The documentation is up-to-date for the 4.60 release. Major new features since |
| 249 | the 4.50 release are: |
| 250 | |
| 251 | . Support for SQLite. |
| 252 | |
| 253 | . Support for IGNOREQUOTA in LMTP. |
| 254 | |
| 255 | . Extensions to the "submission mode" features. |
| 256 | |
| 257 | . Support for Client SMTP Authorization (CSA). |
| 258 | |
| 259 | . Support for ratelimiting hosts and users. |
| 260 | |
| 261 | . New expansion items to help with the BATV "prvs" scheme. |
| 262 | |
| 263 | . A "match_ip" condition, that matches an IP address against a list. |
| 264 | |
| 265 | There are many more minor changes. |
| 266 | |
| 267 | **** |