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ACCESS(5)		      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 informa-
       tion: 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  in-
       dexed 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 di-
       rected to TCP-based server. In those cases, the lookups are done	 in  a
       slightly	different way as described below under "REGULAR	EXPRESSION TA-
       BLES" 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_do-
	      main_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_do-
	      main_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  ex-
       amined 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_do-
	      main_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_do-
	      main_matches_subdomains configuration setting.

       net.work.addr.ess

       net.work.addr

       net.work

       net    Matches  a  remote  IPv4	host address or	network	address	range.
	      Specify one to four decimal octets  separated  by	 ".".  Do  not
	      specify "[]" , "/", leading zeros, or hexadecimal	forms.

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

	      NOTE: 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  a  remote  IPv6	host address or	network	address	range.
	      Specify three to eight hexadecimal octet pairs separated by ":",
	      using  the  compressed  form  "::" for a sequence	of zero-valued
	      octet pairs.  Do	not  specify  "[]",  "/",  leading  zeros,  or
	      non-compressed forms.

	      A	 network  range	 is  matched by	repeatedly truncating the last
	      ":octetpair" from	the compressed-form remote IPv6	 host  address
	      string,  until  a	 match	is found in the	access table, or until
	      further truncation is not	possible.

	      NOTE: 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	gener-
	      ated  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  con-
		     cern.   The "send 521 and disconnect" behavior is NOT de-
		     fined 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 mes-
	      sage.

	      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_de-
	      fer_code	4.7.1	optional  text..."  when  the optional text is
	      specified, otherwise reply with a	generic	 error	response  mes-
	      sage.

	      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,  re-
	      ject_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, with	Postfix	3.0 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  mes-
	      sage.   To discard only one recipient without discarding the en-
	      tire 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 mas-
	      ter.cf; the syntax of the	next-hop destination is	 described  in
	      the  manual  page	of the corresponding delivery agent.  More in-
	      formation	about external content filters is in the Postfix  FIL-
	      TER_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 set-
	      ting, and	affects	all recipients of the  message.	 In  the  case
	      that  multiple  FILTER  actions  fire, only the last one is exe-
	      cuted.

	      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	(Post-
	      fix  2.7 and later), or specify a	transport:destination that de-
	      livers through a different Postfix  instance  (Postfix  2.6  and
	      earlier).	Other options are using	the recipient-dependent	trans-
	      port_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  mes-
	      sage.

	      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 ap-
	      pears before the second etc. prepended header.

	      Note: this action	must execute before the	message	content	is re-
	      ceived;	 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).  When multiple RE-
	      DIRECT actions fire, only	the last one takes effect.

	      Note:  this  action  overrides  the FILTER action, and currently
	      overrides	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, re-
	      cipient 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  in-
	      formation	 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	 Post-
       fix 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  do-
       main 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 interpo-
       lated 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 edit-
       ing 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

       Wietse Venema
       Google, Inc.
       111 8th Avenue
       New York, NY 10011, 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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