# CANONICAL(5) CANONICAL(5)
#
# NAME
# canonical - Postfix canonical table format
#
# SYNOPSIS
# postmap /etc/postfix/canonical
#
# postmap -q "string" /etc/postfix/canonical
#
# postmap -q - /etc/postfix/canonical <inputfile
#
# DESCRIPTION
# The optional canonical(5) table specifies an address map-
# ping for local and non-local addresses. The mapping is
# used by the cleanup(8) daemon, before mail is stored into
# the queue. The address mapping is recursive.
#
# Normally, the canonical(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 /etc/postfix/canonical" 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 regu-
# lar-expression map where patterns are given as regular
# expressions, or lookups can be directed to a 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 canonical(5) mapping affects both message
# header addresses (i.e. addresses that appear inside mes-
# sages) and message envelope addresses (for example, the
# addresses that are used in SMTP protocol commands). This
# is controlled with the canonical_classes parameter.
#
# NOTE: Postfix versions 2.2 and later rewrite message head-
# ers from remote SMTP clients only if the client matches
# the local_header_rewrite_clients parameter, or if the
# remote_header_rewrite_domain configuration parameter spec-
# ifies a non-empty value. To get the behavior before Post-
# fix 2.2, specify "local_header_rewrite_clients =
# static:all".
#
# Typically, one would use the canonical(5) table to replace
# login names by Firstname.Lastname, or to clean up
# addresses produced by legacy mail systems.
#
# The canonical(5) mapping is not to be confused with vir-
# tual alias support or with local aliasing. To change the
# destination but not the headers, use the virtual(5) or
# aliases(5) map instead.
#
# 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 address
# When pattern matches a mail address, replace it by
# the corresponding address.
#
# 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.
#
# TABLE SEARCH ORDER
# With lookups from indexed files such as DB or DBM, or from
# networked tables such as NIS, LDAP or SQL, each
# user@domain query produces a sequence of query patterns as
# described below.
#
# Each query pattern is sent to each specified lookup table
# before trying the next query pattern, until a match is
# found.
#
# user@domain address
# Replace user@domain by address. This form has the
# highest precedence.
#
# This is useful to clean up addresses produced by
# legacy mail systems. It can also be used to pro-
# duce Firstname.Lastname style addresses, but see
# below for a simpler solution.
#
# user address
# Replace user@site by address when site is equal to
# $myorigin, when site is listed in $mydestination,
# or when it is listed in $inet_interfaces or
# $proxy_interfaces.
#
# This form is useful for replacing login names by
# Firstname.Lastname.
#
# @domain address
# Replace other addresses in domain by address. This
# form has the lowest precedence.
#
# Note: @domain is a wild-card. When this form is
# applied to recipient addresses, the Postfix SMTP
# server accepts mail for any recipient in domain,
# regardless of whether that recipient exists. This
# may turn your mail system into a backscatter
# source: Postfix first accepts mail for non-existent
# recipients and then tries to return that mail as
# "undeliverable" to the often forged sender address.
#
# To avoid backscatter with mail for a wild-card
# domain, replace the wild-card mapping with explicit
# 1:1 mappings, or add a reject_unverified_recipient
# restriction for that domain:
#
# smtpd_recipient_restrictions =
# ...
# reject_unauth_destination
# check_recipient_access
# inline:{example.com=reject_unverified_recipient}
# unverified_recipient_reject_code = 550
#
# In the above example, Postfix may contact a remote
# server if the recipient is rewritten to a remote
# address.
#
# RESULT ADDRESS REWRITING
# The lookup result is subject to address rewriting:
#
# o When the result has the form @otherdomain, the
# result becomes the same user in otherdomain.
#
# o When "append_at_myorigin=yes", append "@$myorigin"
# to addresses without "@domain".
#
# o When "append_dot_mydomain=yes", append ".$mydomain"
# to addresses without ".domain".
#
# 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, user+foo, user, and
# @domain.
#
# The propagate_unmatched_extensions parameter controls
# whether an unmatched address extension (+foo) is propa-
# gated to the result of table lookup.
#
# 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 address being looked up. Thus, 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 ta-
# ble, 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 $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_ta-
# ble(5). This feature is not available up to and including
# Postfix version 2.4.
#
# Each lookup operation uses the entire address once. Thus,
# 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.
#
# Results are the same as with indexed file lookups.
#
# BUGS
# The table format does not understand quoting conventions.
#
# CONFIGURATION PARAMETERS
# The following main.cf parameters are especially relevant.
# The text below provides only a parameter summary. See
# postconf(5) for more details including examples.
#
# canonical_classes (envelope_sender, envelope_recipient,
# header_sender, header_recipient)
# What addresses are subject to canonical_maps
# address mapping.
#
# canonical_maps (empty)
# Optional address mapping lookup tables for message
# headers and envelopes.
#
# recipient_canonical_maps (empty)
# Optional address mapping lookup tables for envelope
# and header recipient addresses.
#
# sender_canonical_maps (empty)
# Optional address mapping lookup tables for envelope
# and header sender addresses.
#
# propagate_unmatched_extensions (canonical, virtual)
# What address lookup tables copy an address exten-
# sion from the lookup key to the lookup result.
#
# Other parameters of interest:
#
# inet_interfaces (all)
# The network interface addresses that this mail sys-
# tem receives mail on.
#
# local_header_rewrite_clients (permit_inet_interfaces)
# 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.
#
# proxy_interfaces (empty)
# The network interface addresses that this mail sys-
# tem receives mail on by way of a proxy or network
# address translation unit.
#
# masquerade_classes (envelope_sender, header_sender,
# header_recipient)
# What addresses are subject to address masquerading.
#
# masquerade_domains (empty)
# Optional list of domains whose subdomain structure
# will be stripped off in email addresses.
#
# masquerade_exceptions (empty)
# Optional list of user names that are not subjected
# to address masquerading, even when their addresses
# match $masquerade_domains.
#
# mydestination ($myhostname, localhost.$mydomain, local-
# host)
# The list of domains that are delivered via the
# $local_transport mail delivery transport.
#
# myorigin ($myhostname)
# The domain name that locally-posted mail appears to
# come from, and that locally posted mail is deliv-
# ered to.
#
# owner_request_special (yes)
# Enable special treatment for owner-listname entries
# in the aliases(5) file, and don't split owner-list-
# name and listname-request address localparts when
# the recipient_delimiter is set to "-".
#
# remote_header_rewrite_domain (empty)
# Don't rewrite message headers from remote clients
# at all when this parameter is empty; otherwise, re-
# write 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
# Use "postconf readme_directory" or "postconf html_direc-
# tory" to locate this information.
# DATABASE_README, Postfix lookup table overview
# ADDRESS_REWRITING_README, address rewriting guide
#
# 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
#
# CANONICAL(5)