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 PERMIT action (there is an implied PER-
              MIT  at  the  end  of each restriction list). 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  in  this
              table. This prevents Postfix from trying substrings
              of the lookup key (such as a subdomain name,  or  a
              network address subnetwork).

       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  a  content filter.  More information
              about  content  filters  is  in  the  Postfix  FIL-
              TER_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)