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ACCESS(5)                 FreeBSD File Formats Manual                ACCESS(5)

NAME
       access - Postfix SMTP server access table

SYNOPSIS
       postmap /usr/local/etc/postfix/access

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

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

DESCRIPTION
       This document describes access control on remote SMTP client
       information: host names, network addresses, and envelope sender or
       recipient addresses; it is implemented by the Postfix SMTP server.  See
       header_checks(5) or body_checks(5) for access control on the content of
       email messages.

       Normally, the access(5) 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" to rebuild an
       indexed file after changing the corresponding text file.

       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 expressions, or lookups can be
       directed to TCP-based server. In those cases, the lookups are done in a
       slightly different way as described below under "REGULAR EXPRESSION
       TABLES" or "TCP-BASED TABLES".

CASE FOLDING
       The search string is folded to lowercase before database lookup. As of
       Postfix 2.3, the search string is not case folded with database types
       such as regexp: or pcre: whose lookup fields can match both upper and
       lower case.

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 logical 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 configuration setting.

       .domain.tld
              Matches subdomains of domain.tld, but only when the string
              smtpd_access_maps is not listed in the Postfix
              parent_domain_matches_subdomains configuration setting.

       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 recipient 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 configuration setting.

       .domain.tld
              Matches subdomains of domain.tld, but only when the string
              smtpd_access_maps is not listed in the Postfix
              parent_domain_matches_subdomains configuration setting.

       net.work.addr.ess

       net.work.addr

       net.work

       net    Matches the specified IPv4 host address or subnetwork. An IPv4
              host address is a sequence of four decimal octets separated by
              ".".

              Subnetworks are matched by repeatedly truncating the last
              ".octet" from the remote IPv4 host address string until a match
              is found in the access table, or until further truncation is not
              possible.

              NOTE 1: The access map lookup key must be in canonical form: do
              not specify unnecessary null characters, and do not enclose
              network address information with "[]" characters.

              NOTE 2: use the cidr lookup table type to specify
              network/netmask patterns. See cidr_table(5) for details.

       net:work:addr:ess

       net:work:addr

       net:work

       net    Matches the specified IPv6 host address or subnetwork. An IPv6
              host address is a sequence of three to eight hexadecimal octet
              pairs separated by ":".

              Subnetworks are matched by repeatedly truncating the last
              ":octetpair" from the remote IPv6 host address string until a
              match is found in the access table, or until further truncation
              is not possible.

              NOTE 1: the truncation and comparison are done with the string
              representation of the IPv6 host address. Thus, not all the ":"
              subnetworks will be tried.

              NOTE 2: The access map lookup key must be in canonical form: do
              not specify unnecessary null characters, and do not enclose
              network address information with "[]" characters.

              NOTE 3: use the cidr lookup table type to specify
              network/netmask patterns. See cidr_table(5) for details.

              IPv6 support is available in Postfix 2.2 and later.

ACCEPT ACTIONS

       OK     Accept the address etc. that matches the pattern.

       all-numerical
              An all-numerical result is treated as OK. This format is
              generated by address-based relay authorization schemes such as
              pop-before-smtp.

       For other accept actions, see "OTHER ACTIONS" below.

REJECT ACTIONS
       Postfix version 2.3 and later support enhanced status codes as defined
       in RFC 3463.  When no code is specified at the beginning of the text
       below, Postfix inserts a default enhanced status code of "5.7.1" in the
       case of reject actions, and "4.7.1" in the case of defer actions. See
       "ENHANCED STATUS CODES" below.

       4NN text

       5NN text
              Reject the address etc. that matches the pattern, and respond
              with the numerical three-digit code and text. 4NN means "try
              again later", while 5NN means "do not try again".

              The following responses have special meaning for the Postfix
              SMTP server:

              421 text (Postfix 2.3 and later)

              521 text (Postfix 2.6 and later)
                     After responding with the numerical three-digit code and
                     text, disconnect immediately from the SMTP client.  This
                     frees up SMTP server resources so that they can be made
                     available to another SMTP client.

                     Note: The "521" response should be used only with botnets
                     and other malware where interoperability is of no
                     concern.  The "send 521 and disconnect" behavior is NOT
                     defined in the SMTP standard.

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

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

              This feature is available in Postfix 2.6 and later.

       DEFER_IF_REJECT optional text...
              Defer the request if some later restriction would result in a
              REJECT action. Reply with "$access_map_defer_code 4.7.1 optional
              text..." when the optional text is specified, otherwise reply
              with a generic error response message.

              Prior to Postfix 2.6, the SMTP reply code is 450.

              This feature is available in Postfix 2.1 and later.

       DEFER_IF_PERMIT optional text...
              Defer the request if some later restriction would result in a an
              explicit or implicit PERMIT action.  Reply with
              "$access_map_defer_code 4.7.1  optional text..." when the
              optional text is specified, otherwise reply with a generic error
              response message.

              Prior to Postfix 2.6, the SMTP reply code is 450.

              This feature is available in Postfix 2.1 and later.

       For other reject actions, see "OTHER ACTIONS" below.

OTHER ACTIONS

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

       BCC user@domain
              Send one copy of the message to the specified recipient.

              If multiple BCC actions are specified within the same SMTP MAIL
              transaction, only the last action will be used.

              This feature is available in Postfix 3.0 and later.

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

              Note: this action currently affects all recipients of the
              message.  To discard only one recipient without discarding the
              entire message, use the transport(5) table to direct mail to the
              discard(8) service.

              This feature is available in Postfix 2.0 and later.

       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).

              This feature is available in Postfix 2.0 and later.

       FILTER transport:destination
              After the message is queued, send the entire message through the
              specified external content filter. The transport name specifies
              the first field of a mail delivery agent definition in
              master.cf; the syntax of the next-hop destination is described
              in the manual page of the corresponding delivery agent.  More
              information about external content filters is in the Postfix
              FILTER_README file.

              Note 1: do not use $number regular expression substitutions for
              transport or destination unless you know that the information
              has a trusted origin.

              Note 2: this action overrides the main.cf content_filter
              setting, and affects all recipients of the message. In the case
              that multiple FILTER actions fire, only the last one is
              executed.

              Note 3: the purpose of the FILTER command is to override message
              routing.  To override the recipient's transport but not the
              next-hop destination, specify an empty filter destination
              (Postfix 2.7 and later), or specify a transport:destination that
              delivers through a different Postfix instance (Postfix 2.6 and
              earlier). Other options are using the recipient-dependent
              transport_maps or the sender-dependent
              sender_dependent_default_transport_maps features.

              This feature is available in Postfix 2.0 and later.

       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: use "postsuper -r" to release mail that was kept on hold
              for a significant fraction of $maximal_queue_lifetime or
              $bounce_queue_lifetime, or longer. Use "postsuper -H" only for
              mail that will not expire within a few delivery attempts.

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

              This feature is available in Postfix 2.0 and later.

       PREPEND headername: headervalue
              Prepend the specified message header to the message.  When more
              than one PREPEND action executes, the first prepended header
              appears before the second etc. prepended header.

              Note: this action must execute before the message content is
              received; it cannot execute in the context of
              smtpd_end_of_data_restrictions.

              This feature is available in Postfix 2.1 and later.

       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.

              This feature is available in Postfix 2.1 and later.

       INFO optional text...
              Log an informational record with the optional text, together
              with client information and if available, with helo, sender,
              recipient and protocol information.

              This feature is available in Postfix 3.0 and later.

       WARN optional text...
              Log a warning with the optional text, together with client
              information and if available, with helo, sender, recipient and
              protocol information.

              This feature is available in Postfix 2.1 and later.

ENHANCED STATUS CODES
       Postfix version 2.3 and later support enhanced status codes as defined
       in RFC 3463.  When an enhanced status code is specified in an access
       table, it is subject to modification. The following transformations are
       needed when the same access table is used for client, helo, sender, or
       recipient access restrictions; they happen regardless of whether
       Postfix replies to a MAIL FROM, RCPT TO or other SMTP command.

       o      When a sender address matches a REJECT action, the Postfix SMTP
              server will transform a recipient DSN status (e.g., 4.1.1-4.1.6)
              into the corresponding sender DSN status, and vice versa.

       o      When non-address information matches a REJECT action (such as
              the HELO command argument or the client hostname/address), the
              Postfix SMTP server will transform a sender or recipient DSN
              status into a generic non-address DSN status (e.g., 4.0.0).

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 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.

       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 description of the TCP
       client/server lookup protocol, see tcp_table(5).  This feature is not
       available up to and including Postfix version 2.4.

       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.

EXAMPLE
       The following example uses an indexed file, so that the order of table
       entries does not matter. The example permits access by the client at
       address 1.2.3.4 but rejects all other clients in 1.2.3.0/24. Instead of
       hash lookup tables, some systems use dbm.  Use the command "postconf
       -m" to find out what lookup tables Postfix supports on your system.

       /usr/local/etc/postfix/main.cf:
           smtpd_client_restrictions =
               check_client_access hash:$config_directory/access

       /usr/local/etc/postfix/access:
           1.2.3   REJECT
           1.2.3.4 OK

       Execute the command "postmap /usr/local/etc/postfix/access" after
       editing the file.

BUGS
       The table format does not understand quoting conventions.

SEE ALSO
       postmap(1), Postfix lookup table manager
       smtpd(8), SMTP server
       postconf(5), configuration parameters
       transport(5), transport:nexthop syntax

README FILES
       Use "postconf readme_directory" or "postconf html_directory" to locate
       this information.
       SMTPD_ACCESS_README, built-in SMTP server access control
       DATABASE_README, Postfix lookup table overview

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)

NAME | SYNOPSIS | DESCRIPTION | CASE FOLDING | TABLE FORMAT | EMAIL ADDRESS PATTERNS | EMAIL ADDRESS EXTENSION | HOST NAME/ADDRESS PATTERNS | ACCEPT ACTIONS | REJECT ACTIONS | OTHER ACTIONS | ENHANCED STATUS CODES | REGULAR EXPRESSION TABLES | TCP-BASED TABLES | EXAMPLE | BUGS | SEE ALSO | README FILES | LICENSE | AUTHOR(S)

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