    ACCESS(5)                                               ACCESS(5)

    NAME
           access - format of Postfix access table

    SYNOPSIS
           postmap /etc/postfix/access

           postmap -q "string" /etc/postfix/access

           postmap -q - /etc/postfix/access <inputfile

    DESCRIPTION
           The  optional access table directs the Postfix SMTP server
           to selectively  reject  or  accept  mail.  Access  can  be
           allowed  or  denied for specific host names, domain names,
           networks, host network addresses or mail addresses.

           Normally, the access table is specified  as  a  text  file
           that  serves  as  input  to  the  postmap(1) command.  The
           result, an indexed file in dbm or db format, is  used  for
           fast  searching  by  the  mail system. Execute the command
           postmap  /etc/postfix/access  in  order  to  rebuild   the
           indexed file after changing the access table.

           When  the  table  is provided via other means such as NIS,
           LDAP or SQL, the same lookups are  done  as  for  ordinary
           indexed files.

           Alternatively,  the  table  can  be provided as a regular-
           expression map where patterns are given as regular expres-
           sions,  or lookups can be directed to TCP-based server. In
           that case, the lookups are done in  a  slightly  different
           way  as  described below under "REGULAR EXPRESSION TABLES"
           and "TCP-BASED TABLES".

    TABLE FORMAT
           The input format for the postmap(1) command is as follows:

           pattern action
                  When pattern matches a mail address, domain or host
                  address, perform the corresponding action.

           blank lines and comments
                  Empty lines and whitespace-only lines are  ignored,
                  as  are  lines whose first non-whitespace character
                  is a `#'.

           multi-line text
                  A logical line starts with non-whitespace  text.  A
                  line  that starts with whitespace continues a logi-
                  cal line.

    EMAIL ADDRESS PATTERNS
           With lookups from indexed files such as DB or DBM, or from
           networked  tables  such  as NIS, LDAP or SQL, patterns are
           tried in the order as listed below:

           user@domain
                  Matches the specified mail address.

           domain.tld
                  Matches domain.tld as the domain part of  an  email
                  address.

                  The pattern domain.tld also matches subdomains, but
                  only when the string smtpd_access_maps is listed in
                  the  Postfix  parent_domain_matches_subdomains con-
                  figuration setting (note that this is  the  default
                  for  some versions of Postfix).  Otherwise, specify
                  .domain.tld (note the  initial  dot)  in  order  to
                  match subdomains.

           user@  Matches  all mail addresses with the specified user
                  part.

           Note: lookup of the null sender address  is  not  possible
           with  some types of lookup table. By default, Postfix uses
           <> as the lookup key for  such  addresses.  The  value  is
           specified  with the smtpd_null_access_lookup_key parameter
           in the Postfix main.cf file.

    EMAIL ADDRESS EXTENSION
           When a mail address localpart contains the optional recip-
           ient  delimiter  (e.g., user+foo@domain), the lookup order
           becomes: user+foo@domain, user@domain, domain,  user+foo@,
           and user@.

    HOST NAME/ADDRESS PATTERNS
           With lookups from indexed files such as DB or DBM, or from
           networked tables such as NIS, LDAP or SQL,  the  following
           lookup patterns are examined in the order as listed:

           domain.tld
                  Matches domain.tld.

                  The pattern domain.tld also matches subdomains, but
                  only when the string smtpd_access_maps is listed in
                  the  Postfix  parent_domain_matches_subdomains con-
                  figuration setting.  Otherwise, specify .domain.tld
                  (note  the  initial  dot)  in order to match subdo-
                  mains.

           net.work.addr.ess

           net.work.addr

           net.work

           net    Matches any host address in the specified  network.
                  A  network  address  is  a  sequence of one or more
                  octets separated by ".".

                  NOTE: use the cidr lookup  table  type  to  specify
                  network/netmask  patterns.  See  cidr_table(5)  for
                  details.

    ACTIONS
           [45]NN text
                  Reject the address etc. that matches  the  pattern,
                  and respond with the numerical code and text.

           REJECT optional text...
                  Reject  the  address etc. that matches the pattern.
                  Reply with $reject_code optional text...  when  the
                  optional  text is specified, otherwise reply with a
                  generic error response message.

           DEFER_IF_REJECT optional text...
                  Defer the request if some later  restriction  would
                  result in a REJECT action. Reply with "450 optional
                  text... when the optional text is specified, other-
                  wise reply with a generic error response message.

           DEFER_IF_PERMIT optional text...
                  Defer  the  request if some later restriction would
                  result in a an explicit or implicit PERMIT  action.
                  Reply  with "450 optional text... when the optional
                  text is specified, otherwise reply with  a  generic
                  error response message.

           OK     Accept the address etc. that matches the pattern.

           all-numerical
                  An all-numerical result is treated as OK. This for-
                  mat is generated by address-based relay  authoriza-
                  tion schemes.

           DUNNO  Pretend  that  the  lookup  key was not found. This
                  prevents Postfix  from  trying  substrings  of  the
                  lookup  key (such as a subdomain name, or a network
                  address subnetwork).

           PREPEND headername: headervalue
                  Prepend the specified message header  to  the  mes-
                  sage.  When this action is used multiple times, the
                  first prepended header appears  before  the  second
                  etc. prepended header.

                  Note:  this action does not support multi-line mes-
                  sage headers.

           HOLD optional text...
                  Place the message on the hold queue, where it  will
                  sit  until someone either deletes it or releases it
                  for delivery.  Log the optional text if  specified,
                  otherwise log a generic message.

                  Mail  that  is  placed on hold can be examined with
                  the postcat(1) command, and  can  be  destroyed  or
                  released with the postsuper(1) command.

                  Note:  this action currently affects all recipients
                  of the message.

           DISCARD optional text...
                  Claim successful delivery and silently discard  the
                  message.   Log the optional text if specified, oth-
                  erwise log a generic message.

                  Note: this action currently affects all  recipients
                  of the message.

           FILTER transport:destination
                  After  the  message is queued, send the entire mes-
                  sage through the specified external content filter.
                  More  information about external content filters is
                  in the Postfix FILTER_README file.

                  Note:  this  action  overrides  the  main.cf   con-
                  tent_filter  setting,  and  currently  affects  all
                  recipients of the message.

           REDIRECT user@domain
                  After the message is queued, send  the  message  to
                  the  specified  address  instead  of  the  intended
                  recipient(s).

                  Note: this action overrides the FILTER action,  and
                  currently affects all recipients of the message.

           restriction...
                  Apply the named UCE restriction(s) (permit, reject,
                  reject_unauth_destination, and so on).

    REGULAR EXPRESSION TABLES
           This section describes how the table lookups  change  when
           the table is given in the form of regular expressions. For
           a description of regular expression lookup  table  syntax,
           see regexp_table(5) or pcre_table(5).

           Each  pattern  is  a regular expression that is applied to
           the entire string being looked up. Depending on the appli-
           cation,  that  string  is  an  entire  client hostname, an
           entire client IP address, or an entire mail address. Thus,
           no  parent  domain  or  parent  network  search  is  done,
           user@domain mail addresses are not broken  up  into  their
           user@ and domain constituent parts, nor is user+foo broken
           up into user and foo.

           Patterns are applied in the  order  as  specified  in  the
           table,  until  a  pattern is found that matches the search
           string.

           Actions are the same as with indexed  file  lookups,  with
           the  additional feature that parenthesized substrings from
           the pattern can be interpolated as $1, $2 and so on.

    TCP-BASED TABLES
           This section describes how the table lookups  change  when
           lookups are directed to a TCP-based server. For a descrip-
           tion  of  the  TCP  client/server  lookup  protocol,   see
           tcp_table(5).

           Each  lookup  operation uses the entire query string once.
           Depending on the application, that  string  is  an  entire
           client hostname, an entire client IP address, or an entire
           mail address.  Thus, no parent domain  or  parent  network
           search  is done, user@domain mail addresses are not broken
           up into their user@ and domain constituent parts,  nor  is
           user+foo broken up into user and foo.

           Actions are the same as with indexed file lookups.

    BUGS
           The  table format does not understand quoting conventions.

    SEE ALSO
           postmap(1) create lookup table
           smtpd(8) smtp server
           cidr_table(5) format of CIDR tables
           pcre_table(5) format of PCRE tables
           regexp_table(5) format of POSIX regular expression tables
           tcp_table(5) TCP client/server table lookup protocol

    LICENSE
           The Secure Mailer license must be  distributed  with  this
           software.

    AUTHOR(S)
           Wietse Venema
           IBM T.J. Watson Research
           P.O. Box 704
           Yorktown Heights, NY 10598, USA

                                                            ACCESS(5)