ACCESS(5)                                               ACCESS(5)

NAME
       access - format of Postfix access table

SYNOPSIS
       postmap /usr/local/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  /usr/local/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.name
              Matches  domain.name as the domain part of an email
              address.

              The pattern domain.name  also  matches  subdomains,
              but  only  when  the  string  smtpd_access_maps  is
              listed in the Postfix  parent_domain_matches_subdo-
              mains  configuration  setting.   Otherwise, specify
              .domain.name (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    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.name
              Matches domain.name.

              The pattern domain.name  also  matches  subdomains,
              but  only  when  the  string  smtpd_access_maps  is
              listed in the Postfix  parent_domain_matches_subdo-
              mains  configuration  setting.   Otherwise, specify
              .domain.name (note the initial  dot)  in  order  to
              match subdomains.

       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)