#++
# NAME
#	canonical 5
# SUMMARY
#	Postfix canonical table format
# SYNOPSIS
#	\fBpostmap /etc/postfix/canonical\fR
#
#	\fBpostmap -q "\fIstring\fB" /etc/postfix/canonical\fR
#
#	\fBpostmap -q - /etc/postfix/canonical <\fIinputfile\fR
# DESCRIPTION
#	The optional \fBcanonical\fR(5) table specifies an address mapping for
#	local and non-local addresses. The mapping is used by the
#	\fBcleanup\fR(8) daemon, before mail is stored into the
#	queue.  The address mapping is recursive.
#
#	Normally, the \fBcanonical\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/canonical\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".
#
#	By default the \fBcanonical\fR(5) mapping affects both message
#	header addresses (i.e. addresses that appear inside messages)
#	and message envelope addresses (for example, the addresses
#	that are used in SMTP protocol commands). This is controlled with
#	the \fBcanonical_classes\fR parameter.
#
#	NOTE: Postfix versions 2.2 and later rewrite message headers
#	from remote SMTP clients only if the client matches the
#	local_header_rewrite_clients parameter, or if the
#	remote_header_rewrite_domain configuration parameter specifies
#	a non-empty value. To get the behavior before Postfix 2.2,
#	specify "local_header_rewrite_clients = static:all".
#
#	Typically, one would use the \fBcanonical\fR(5) table to replace login
#	names by \fIFirstname.Lastname\fR, or to clean up addresses produced
#	by legacy mail systems.
#
#	The \fBcanonical\fR(5) mapping is not to be confused with \fIvirtual
#	alias\fR support or with local aliasing. To change the destination
#	but not the headers, use the \fBvirtual\fR(5) or \fBaliases\fR(5)
#	map instead.
# 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 address\fR"
#	When \fIpattern\fR matches a mail address, replace it by the
#	corresponding \fIaddress\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.
# TABLE SEARCH ORDER
# .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 address\fR"
#	Replace \fIuser\fR@\fIdomain\fR by \fIaddress\fR. This form
#	has the highest precedence.
#	.sp
#	This is useful to clean up addresses produced by legacy mail systems.
#	It can also be used to produce \fIFirstname.Lastname\fR style
#	addresses, but see below for a simpler solution.
# .IP "\fIuser address\fR"
#	Replace \fIuser\fR@\fIsite\fR by \fIaddress\fR when \fIsite\fR is
#	equal to $\fBmyorigin\fR, when \fIsite\fR is listed in
#	$\fBmydestination\fR, or when it is listed in $\fBinet_interfaces\fR
#	or $\fBproxy_interfaces\fR.
#	.sp
#	This form is useful for replacing login names by
#	\fIFirstname.Lastname\fR.
# .IP "@\fIdomain address\fR"
#	Replace other addresses in \fIdomain\fR by \fIaddress\fR.
#	This form has the lowest precedence.
# .sp
#	Note: @\fIdomain\fR is a wild-card. When this form is applied
#	to recipient addresses, the Postfix SMTP server accepts
#	mail for any recipient in \fIdomain\fR, regardless of whether
#	that recipient exists.  This may turn your mail system into
#	a backscatter source: Postfix first accepts mail for
#	non-existent recipients and then tries to return that mail
#	as "undeliverable" to the often forged sender address.
# RESULT ADDRESS REWRITING
# .ad
# .fi
#	The lookup result is subject to address rewriting:
# .IP \(bu
#	When the result has the form @\fIotherdomain\fR, the
#	result becomes the same \fIuser\fR in \fIotherdomain\fR.
# .IP \(bu
#	When "\fBappend_at_myorigin=yes\fR", append "\fB@$myorigin\fR"
#	to addresses without "@domain".
# .IP \(bu
#	When "\fBappend_dot_mydomain=yes\fR", append
#	"\fB.$mydomain\fR" to addresses without ".domain".
# 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, \fIuser+foo\fR,
#	\fIuser\fR, and @\fIdomain\fR.
#
#	The \fBpropagate_unmatched_extensions\fR parameter controls whether
#	an unmatched address extension (\fI+foo\fR) is propagated to the 
#	result of table lookup.
# 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
#	address being looked up. Thus, \fIuser@domain\fR mail addresses are not
#	broken up into their \fIuser\fR and \fI@domain\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.
#
#	Results 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 address once.  Thus,
#	\fIuser@domain\fR mail addresses are not broken up into their
#	\fIuser\fR and \fI@domain\fR constituent parts, nor is
#	\fIuser+foo\fR broken up into \fIuser\fR and \fIfoo\fR.
#
#	Results are the same as with indexed file lookups.
# BUGS
#	The table format does not understand quoting conventions.
# CONFIGURATION PARAMETERS
# .ad
# .fi
#	The following \fBmain.cf\fR parameters are especially relevant.  
#	The text below provides only a parameter summary. See
#	\fBpostconf\fR(5) for more details including examples.
# .IP \fBcanonical_classes\fR
#	What addresses are subject to canonical address mapping.
# .IP \fBcanonical_maps\fR
#	List of canonical mapping tables.
# .IP \fBrecipient_canonical_maps\fR
#	Address mapping lookup table for envelope and header recipient
#	addresses.
# .IP \fBsender_canonical_maps\fR
#	Address mapping lookup table for envelope and header sender
#	addresses.
# .IP \fBpropagate_unmatched_extensions\fR 
#	A list of address rewriting or forwarding mechanisms that propagate
#	an address extension from the original address to the result.
#	Specify zero or more of \fBcanonical\fR, \fBvirtual\fR, \fBalias\fR,  
#	\fBforward\fR, \fBinclude\fR, or \fBgeneric\fR.
# .PP
#	Other parameters of interest:
# .IP \fBinet_interfaces\fR
#	The network interface addresses that this system receives mail on.
#	You need to stop and start Postfix when this parameter changes.
# .IP \fBlocal_header_rewrite_clients\fR
#	Rewrite message header addresses in mail from these clients
#	and update incomplete addresses with the domain name in
#	$myorigin or $mydomain; either don't rewrite message headers
#	from other clients at all, or rewrite message headers and
#	update incomplete addresses with the domain specified in
#	the remote_header_rewrite_domain parameter.
# .IP \fBproxy_interfaces\fR
#	Other interfaces that this machine receives mail on by way of a
#	proxy agent or network address translator.
# .IP \fBmasquerade_classes\fR
#	List of address classes subject to masquerading: zero or more of
#	\fBenvelope_sender\fR, \fBenvelope_recipient\fR, \fBheader_sender\fR, 
#	\fBheader_recipient\fR.
# .IP \fBmasquerade_domains\fR
#	List of domains that hide their subdomain structure.
# .IP \fBmasquerade_exceptions\fR
#	List of user names that are not subject to address masquerading.
# .IP \fBmydestination\fR
#	List of domains that this mail system considers local.
# .IP \fBmyorigin\fR
#	The domain that is appended to locally-posted mail.
# .IP \fBowner_request_special\fR
#	Give special treatment to \fBowner-\fIxxx\fR and \fIxxx\fB-request\fR
#	addresses.
# .IP \fBremote_header_rewrite_domain\fR
#	Don't rewrite message headers from remote clients at all
#	when this parameter is empty; otherwise, rewrite message
#	headers and append the specified domain name to incomplete
#	addresses.
# SEE ALSO
#	cleanup(8), canonicalize and enqueue mail
#	postmap(1), Postfix lookup table manager
#	postconf(5), configuration parameters
#	virtual(5), virtual aliasing
# README FILES
# .ad
# .fi
#	Use "\fBpostconf readme_directory\fR" or
#	"\fBpostconf html_directory\fR" to locate this information.
# .na
# .nf
#	DATABASE_README, Postfix lookup table overview
#	ADDRESS_REWRITING_README, address rewriting guide
# 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
#
#	Wietse Venema
#	Google, Inc.
#	111 8th Avenue
#	New York, NY 10011, USA
#--