doc/doc-txt/NewStuff

   1 $Cambridge: exim/doc/doc-txt/NewStuff,v 1.118 2006/10/23 13:24:21 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 before doing the
 137    expansions, thus setting message-specific variables such as $message_size
 138    and the header variables. This feature is provided to make it easier to test
 139    expansions that make use of these variables. However, Exim must be called by
 140    an admin user when -Mset is used.
 141
 142
 143 Version 4.63
 144 ------------
 145
 146 1. There is a new Boolean option called filter_prepend_home for the redirect
 147    router.
 148
 149 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
 150    start of receiving a non-SMTP message, before any of the message has been
 151    read.
 152
 153 3. When an SMTP error message is specified in a "message" modifier in an ACL,
 154    or in a :fail: or :defer: message in a redirect router, Exim now checks the
 155    start of the message for an SMTP error code.
 156
 157 4. There is a new parameter for LDAP lookups called "referrals", which takes
 158    one of the settings "follow" (the default) or "nofollow".
 159
 160 5. Version 20070721.2 of exipick now included, offering these new options:
 161     --reverse
 162         After all other sorting options have bee processed, reverse order
 163         before displaying messages (-R is synonym).
 164     --random
 165         Randomize order of matching messages before displaying.
 166     --size
 167         Instead of displaying the matching messages, display the sum
 168         of their sizes.
 169     --sort <variable>[,<variable>...]
 170         Before displaying matching messages, sort the messages according to
 171         each messages value for each variable.
 172     --not
 173         Negate the value for every test (returns inverse output from the
 174         same criteria without --not).
 175
 176
 177 Version 4.62
 178 ------------
 179
 180 1. The ${readsocket expansion item now supports Internet domain sockets as well
 181    as Unix domain sockets. If the first argument begins "inet:", it must be of
 182    the form "inet:host:port". The port is mandatory; it may be a number or the
 183    name of a TCP port in /etc/services. The host may be a name, or it may be an
 184    IP address. An ip address may optionally be enclosed in square brackets.
 185    This is best for IPv6 addresses. For example:
 186
 187      ${readsocket{inet:[::1]:1234}{<request data>}...
 188
 189    Only a single host name may be given, but if looking it up yield more than
 190    one IP address, they are each tried in turn until a connection is made. Once
 191    a connection has been made, the behaviour is as for ${readsocket with a Unix
 192    domain socket.
 193
 194 2. If a redirect router sets up file or pipe deliveries for more than one
 195    incoming address, and the relevant transport has batch_max set greater than
 196    one, a batch delivery now occurs.
 197
 198 3. The appendfile transport has a new option called maildirfolder_create_regex.
 199    Its value is a regular expression. For a maildir delivery, this is matched
 200    against the maildir directory; if it matches, Exim ensures that a
 201    maildirfolder file is created alongside the new, cur, and tmp directories.
 202
 203
 204 Version 4.61
 205 ------------
 206
 207 The documentation is up-to-date for the 4.61 release. Major new features since
 208 the 4.60 release are:
 209
 210 . An option called disable_ipv6, to disable the use of IPv6 completely.
 211
 212 . An increase in the number of ACL variables to 20 of each type.
 213
 214 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
 215   $2, $3, (though those are still set) because the numeric variables get used
 216   for other things in complicated expansions.
 217
 218 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
 219
 220 . It is possible to use setclassresources() on some BSD OS to control the
 221   resources used in pipe deliveries.
 222
 223 . A new ACL modifier called add_header, which can be used with any verb.
 224
 225 . More errors are detectable in retry rules.
 226
 227 There are a number of other additions too.
 228
 229
 230 Version 4.60
 231 ------------
 232
 233 The documentation is up-to-date for the 4.60 release. Major new features since
 234 the 4.50 release are:
 235
 236 . Support for SQLite.
 237
 238 . Support for IGNOREQUOTA in LMTP.
 239
 240 . Extensions to the "submission mode" features.
 241
 242 . Support for Client SMTP Authorization (CSA).
 243
 244 . Support for ratelimiting hosts and users.
 245
 246 . New expansion items to help with the BATV "prvs" scheme.
 247
 248 . A "match_ip" condition, that matches an IP address against a list.
 249
 250 There are many more minor changes.
 251
 252 ****