#++
# NAME
#	access 5
# SUMMARY
#	Postfix SMTP server access table
# SYNOPSIS
#	\fBpostmap /etc/postfix/access\fR
#
#	\fBpostmap -q "\fIstring\fB" /etc/postfix/access\fR
#
#	\fBpostmap -q - /etc/postfix/access <\fIinputfile\fR
# 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 \fBheader_checks\fR(5) or
#	\fBbody_checks\fR(5) for access control on the content of
#	email messages.
#
#	Normally, the \fBaccess\fR(5) table is specified as a text file
#	that serves as input to the \fBpostmap\fR(1) command.
#	The result, an indexed file in \fBdbm\fR or \fBdb\fR format,
#	is used for fast searching by the mail system. Execute the
#	command "\fBpostmap /etc/postfix/access\fR" 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
# .ad
# .fi
#	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
# .ad
# .fi
#	The input format for the \fBpostmap\fR(1) command is as follows:
# .IP "\fIpattern action\fR"
#	When \fIpattern\fR matches a mail address, domain or host address,
#	perform the corresponding \fIaction\fR.
# .IP "blank lines and comments"
#	Empty lines and whitespace-only lines are ignored, as
#	are lines whose first non-whitespace character is a `#'.
# .IP "multi-line text"
#	A logical line starts with non-whitespace text. A line that
#	starts with whitespace continues a logical line.
# EMAIL ADDRESS PATTERNS
# .ad
# .fi
#	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:
# .IP \fIuser\fR@\fIdomain\fR
#	Matches the specified mail address.
# .IP \fIdomain.tld\fR
#	Matches \fIdomain.tld\fR as the domain part of an email address.
# .sp
#	The pattern \fIdomain.tld\fR also matches subdomains, but only
#	when the string \fBsmtpd_access_maps\fR is listed in the Postfix
#	\fBparent_domain_matches_subdomains\fR configuration setting
#	(note that this is the default for some versions of Postfix).
#	Otherwise, specify \fI.domain.tld\fR (note the initial dot) in
#	order to match subdomains.
# .IP \fIuser\fR@
#	Matches all mail addresses with the specified user part.
# .PP
#	Note: lookup of the null sender address is not possible with
#	some types of lookup table. By default, Postfix uses \fB<>\fR
#	as the lookup key for such addresses. The value is specified with
#	the \fBsmtpd_null_access_lookup_key\fR parameter in the Postfix
#	\fBmain.cf\fR file.
# EMAIL ADDRESS EXTENSION
# .fi
# .ad
#	When a mail address localpart contains the optional recipient delimiter
#	(e.g., \fIuser+foo\fR@\fIdomain\fR), the lookup order becomes:
#	\fIuser+foo\fR@\fIdomain\fR, \fIuser\fR@\fIdomain\fR, \fIdomain\fR,
#	\fIuser+foo\fR@, and \fIuser\fR@.
# HOST NAME/ADDRESS PATTERNS
# .ad
# .fi
#	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:
# .IP \fIdomain.tld\fR
#	Matches \fIdomain.tld\fR.
# .sp
#	The pattern \fIdomain.tld\fR also matches subdomains, but only
#	when the string \fBsmtpd_access_maps\fR is listed in the Postfix
#	\fBparent_domain_matches_subdomains\fR configuration setting.
#	Otherwise, specify \fI.domain.tld\fR (note the initial dot) in
#	order to match subdomains.
# .IP \fInet.work.addr.ess\fR
# .IP \fInet.work.addr\fR
# .IP \fInet.work\fR
# .IP \fInet\fR
#	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 \fBcidr\fR lookup table type to specify
#	network/netmask patterns. See \fBcidr_table\fR(5) for details.
# .IP \fInet:work:addr:ess\fR
# .IP \fInet:work:addr\fR
# .IP \fInet:work\fR
# .IP \fInet\fR
#	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 \fBcidr\fR lookup table type to specify
#	network/netmask patterns. See \fBcidr_table\fR(5) for details.
#
#	IPv6 support is available in Postfix 2.2 and later.
# ACCEPT ACTIONS
# .ad
# .fi
# .IP \fBOK\fR
#	Accept the address etc. that matches the pattern.
# .IP \fIall-numerical\fR
#	An all-numerical result is treated as OK. This format is
#	generated by address-based relay authorization schemes
#	such as pop-before-smtp.
# REJECT ACTIONS
# .ad
# .fi
#	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 \fItext\fR
#	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.
# .IP "\fB4\fINN text\fR"
# .IP "\fB5\fINN text\fR"
#	Reject the address etc. that matches the pattern, and respond with
#	the numerical three-digit code and text. \fB4\fINN\fR means "try
#	again later", while \fB5\fINN\fR means "do not try again".
# .IP
#	The reply code "421" causes Postfix to disconnect immediately
#	(Postfix version 2.3 and later).
# .IP "\fBREJECT \fIoptional text...\fR
#	Reject the address etc. that matches the pattern. Reply with
#	\fI$reject_code optional text...\fR when the optional text is
#	specified, otherwise reply with a generic error response message.
# .IP "\fBDEFER_IF_REJECT \fIoptional text...\fR
#	Defer the request if some later restriction would result in a
#	REJECT action. Reply with "\fB450 4.7.1 \fI optional
#	text...\fR when the
#	optional text is specified, otherwise reply with a generic error
#	response message.
# .sp
#	This feature is available in Postfix 2.1 and later.
# .IP "\fBDEFER_IF_PERMIT \fIoptional text...\fR
#	Defer the request if some later restriction would result in a
#	an explicit or implicit PERMIT action.
#	Reply with "\fB450 4.7.1 \fI optional text...\fR when the
#	optional text is specified, otherwise reply with a generic error
#	response message.
# .sp
#	This feature is available in Postfix 2.1 and later.
# OTHER ACTIONS
# .ad
# .fi
# .IP \fIrestriction...\fR
#	Apply the named UCE restriction(s) (\fBpermit\fR, \fBreject\fR,
#	\fBreject_unauth_destination\fR, and so on).
# \" .IP "\fBDELAY \fItime\fR"
# \"	Place the message into the deferred queue, and delay the
# \"	initial delivery attempt by \fItime\fR. The time value may
# \"	be followed by a one-character suffix that specifies the
# \"	time unit: s (seconds), m (minutes), h (hours), d (days),
# \"	w (weeks).  The default time unit is s (seconds).
# \" .sp
# \"	Limitations:
# \" .RS
# \" .IP \(bu
# \"	This action affects all the recipients of the message.
# \" .IP \(bu
# \"	The delay value has no effect with remote file systems that
# \"	don't correctly emulate UNIX local file system semantics.
# \"	In that case, the delay will be half of $queue_run_delay
# \"	on average.
# \" .IP \(bu
# \"	Mail will still be delivered with "sendmail -q", "postfix
# \"	flush" or "postqueue -f".
# \" .IP \(bu
# \"	Delayed mail increases the amount of disk I/O during deferred
# \"	queue scans. When large amounts of mail are queued for
# \"	delayed delivery it may be preferable to use the HOLD feature
# \"	instead.
# \" .RE
# \" .IP
# \"	This feature is available in Postfix 2.3 and later.
# .IP "\fBDISCARD \fIoptional text...\fR
#	Claim successful delivery and silently discard the message.
#	Log the optional text if specified, otherwise log a generic
#	message.
# .sp
#	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.
# .sp
#	This feature is available in Postfix 2.0 and later.
# .IP \fBDUNNO\fR
#	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).
# .sp
#	This feature is available in Postfix 2.0 and later.
# .IP "\fBFILTER \fItransport:destination\fR"
#	After the message is queued, send the entire message through
#       the specified external content filter. The \fItransport:destination\fR
#	syntax is described in the \fBtransport\fR(5) manual page.
#	More information
#	about external content filters is in the Postfix FILTER_README file.
# .sp
#	Note: this action overrides the \fBcontent_filter\fR setting,
#	and currently affects all recipients of the message.
# .sp
#	This feature is available in Postfix 2.0 and later.
# .IP "\fBHOLD \fIoptional text...\fR"
#	Place the message on the \fBhold\fR 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
#	\fBpostcat\fR(1) command, and can be destroyed or released with
#	the \fBpostsuper\fR(1) command. 
# .sp
#	Note: use "\fBpostsuper -r\fR" to release mail that was kept on
#	hold for a significant fraction of \fB$maximal_queue_lifetime\fR
#	or \fB$bounce_queue_lifetime\fR, or longer. Use "\fBpostsuper -H\fR"
#	only for mail that will not expire within a few delivery attempts.
# .sp
#	Note: this action currently affects all recipients of the message.
# .sp
#	This feature is available in Postfix 2.0 and later.
# .IP "\fBPREPEND \fIheadername: headervalue\fR"
#	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.
# .sp
#	Note: this action must execute before the message content
#	is received; it cannot execute in the context of
#	\fBsmtpd_end_of_data_restrictions\fR.
# .sp
#	This feature is available in Postfix 2.1 and later.
# .IP "\fBREDIRECT \fIuser@domain\fR"
#	After the message is queued, send the message to the specified
#       address instead of the intended recipient(s).
# .sp
#	Note: this action overrides the FILTER action, and currently affects
#	all recipients of the message.
# .sp
#	This feature is available in Postfix 2.1 and later.
# .IP "\fBWARN \fIoptional text...\fR
#	Log a warning with the optional text, together with client information
#	and if available, with helo, sender, recipient and protocol information.
# .sp
#	This feature is available in Postfix 2.1 and later.
# ENHANCED STATUS CODES
# .ad
# .fi
#	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.
# .IP \(bu
#	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.
# .IP \(bu
#	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
# .ad
# .fi
#	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 \fBregexp_table\fR(5)
#	or \fBpcre_table\fR(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, \fIuser@domain\fR mail addresses are not broken up into
#	their \fIuser@\fR and \fIdomain\fR constituent parts, nor is
#	\fIuser+foo\fR broken up into \fIuser\fR and \fIfoo\fR.
#
#	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 \fB$1\fR, \fB$2\fR and so on.
# TCP-BASED TABLES
# .ad
# .fi
#	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 \fBtcp_table\fR(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,
#	\fIuser@domain\fR mail addresses are not broken up into
#	their \fIuser@\fR and \fIdomain\fR constituent parts, nor is
#	\fIuser+foo\fR broken up into \fIuser\fR and \fIfoo\fR.
#
#	Actions are the same as with indexed file lookups.
# EXAMPLE
# .ad
# .fi
#	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 \fBhash\fR lookup
#	tables, some systems use \fBdbm\fR.  Use the command
#	"\fBpostconf -m\fR" to find out what lookup tables Postfix
#	supports on your system.
#
# .nf
# .na
#	/etc/postfix/main.cf:
#	    smtpd_client_restrictions = 
#	        check_client_access hash:/etc/postfix/access
#
#	/etc/postfix/access:
#	    1.2.3   REJECT
#	    1.2.3.4 OK
# .fi
# .ad
#
#	Execute the command "\fBpostmap /etc/postfix/access\fR" 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
# .ad
# .fi
#	Use "\fBpostconf readme_directory\fR" or
#	"\fBpostconf html_directory\fR" to locate this information.
# .na
# .nf
#	SMTPD_ACCESS_README, built-in SMTP server access control
#	DATABASE_README, Postfix lookup table overview
# LICENSE
# .ad
# .fi
#	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
#--
