    ACCESS(5)                                               ACCESS(5)

    NAME
           access - format of Postfix access table

    SYNOPSIS
           postmap /etc/postfix/access

    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.  In  that  case, the lookups are done in a slightly
           different way as described below.

    TABLE FORMAT
           The format of the access table 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,  the  following
           lookup patterns are examined in the order as listed:

           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.  Otherwise, specify .domain.tld
                  (note the initial dot) in  order  to  match  subdo-
                  mains.

           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    workaround   is   to   specify
           smtpd_null_access_lookup_key  parameter  in  the   Postfix
           main.cf file.

    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 ".".

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

           REJECT Reject the address etc. that matches the pattern. A
                  generic error response message is generated.

           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.

           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.

    BUGS
           The table format does not understand quoting  conventions.

    SEE ALSO
           postmap(1) create mapping table
           smtpd(8) smtp server
           pcre_table(5) format of PCRE tables
           regexp_table(5) format of POSIX regular expression tables

    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)