# VIRTUAL(5) VIRTUAL(5)
#
# NAME
# virtual - Postfix virtual alias table format
#
# SYNOPSIS
# postmap /etc/postfix/virtual
#
# postmap -q "string" /etc/postfix/virtual
#
# postmap -q - /etc/postfix/virtual <inputfile
#
# DESCRIPTION
# The optional virtual(5) alias table rewrites recipient
# addresses for all local, all virtual, and all remote mail
# destinations. This is unlike the aliases(5) table which
# is used only for local(8) delivery. This feature is imple-
# mented in the Postfix cleanup(8) daemon before mail is
# queued.
#
# Virtual aliasing is recursive; to terminate recursion for
# a specific address, alias that address to itself.
#
# The main applications of virtual aliasing are:
#
# o To redirect mail for one address to one or more
# addresses.
#
# o To implement virtual alias domains where all
# addresses are aliased to addresses in other
# domains.
#
# Virtual alias domains are not to be confused with
# the virtual mailbox domains that are implemented
# with the Postfix virtual(8) mail delivery agent.
# With virtual mailbox domains, each recipient
# address can have its own mailbox.
#
# Virtual aliasing is applied only to recipient envelope
# addresses, and does not affect message headers. Use
# canonical(5) mapping to rewrite header and envelope
# addresses in general.
#
# Normally, the virtual(5) alias 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/virtual" 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 case, 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 address, 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, address, ...
# Redirect mail for user@domain to address. This
# form has the highest precedence.
#
# user address, address, ...
# Redirect mail for user@site to address when site is
# equal to $myorigin, when site is listed in $mydes-
# tination, or when it is listed in $inet_interfaces
# or $proxy_interfaces.
#
# This functionality overlaps with the functionality
# of the local aliases(5) database. The difference is
# that virtual(5) mapping can be applied to non-local
# addresses.
#
# @domain address, address, ...
# Redirect mail for other users in domain to address.
# This form has the lowest precedence.
#
# Note: @domain is a wild-card. With this form, the
# Postfix SMTP server accepts mail for any recipient
# in domain, regardless of whether that recipient
# exists. This may turn your mail system into a
# backscatter source: Postfix first accepts mail for
# non-existent recipients and then tries to return
# that mail as "undeliverable" to the often forged
# sender address.
#
# To avoid backscatter with mail for a wild-card
# domain, replace the wild-card mapping with explicit
# 1:1 mappings, or add a reject_unverified_recipient
# restriction for that domain:
#
# smtpd_recipient_restrictions =
# ...
# reject_unauth_destination
# check_recipient_access
# inline:{example.com=reject_unverified_recipient}
# unverified_recipient_reject_code = 550
#
# In the above example, Postfix may contact a remote
# server if the recipient is aliased to a remote
# address.
#
# RESULT ADDRESS REWRITING
# The lookup result is subject to address rewriting:
#
# o When the result has the form @otherdomain, the
# result becomes the same user in otherdomain. This
# works only for the first address in a multi-address
# lookup result.
#
# o When "append_at_myorigin=yes", append "@$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 a table lookup.
#
# VIRTUAL ALIAS DOMAINS
# Besides virtual aliases, the virtual alias table can also
# be used to implement virtual alias domains. With a virtual
# alias domain, all recipient addresses are aliased to
# addresses in other domains.
#
# Virtual alias domains are not to be confused with the vir-
# tual mailbox domains that are implemented with the Postfix
# virtual(8) mail delivery agent. With virtual mailbox
# domains, each recipient address can have its own mailbox.
#
# With a virtual alias domain, the virtual domain has its
# own user name space. Local (i.e. non-virtual) usernames
# are not visible in a virtual alias domain. In particular,
# local aliases(5) and local mailing lists are not visible
# as localname@virtual-alias.domain.
#
# Support for a virtual alias domain looks like:
#
# /etc/postfix/main.cf:
# virtual_alias_maps = hash:/etc/postfix/virtual
#
# Note: some systems use dbm databases instead of hash. See
# the output from "postconf -m" for available database
# types.
#
# /etc/postfix/virtual:
# virtual-alias.domain anything (right-hand content does not matter)
# postmaster@virtual-alias.domain postmaster
# user1@virtual-alias.domain address1
# user2@virtual-alias.domain address2, address3
#
# The virtual-alias.domain anything entry is required for a
# virtual alias domain. Without this entry, mail is rejected
# with "relay access denied", or bounces with "mail loops
# back to myself".
#
# Do not specify virtual alias domain names in the main.cf
# mydestination or relay_domains configuration parameters.
#
# With a virtual alias domain, the Postfix SMTP server
# accepts mail for known-user@virtual-alias.domain, and
# rejects mail for unknown-user@virtual-alias.domain as
# undeliverable.
#
# Instead of specifying the virtual alias domain name via
# the virtual_alias_maps table, you may also specify it via
# the main.cf virtual_alias_domains configuration parameter.
# This latter parameter uses the same syntax as the main.cf
# mydestination configuration parameter.
#
# 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, $2 and so on.
#
# TCP-BASED TABLES
# This section describes how the table lookups change when
# lookups are directed to a TCP-based server. For a descrip-
# tion of the TCP client/server lookup protocol, see tcp_ta-
# ble(5). This feature is available in Postfix 2.5 and
# later.
#
# Each lookup operation uses the entire address once. Thus,
# user@domain mail addresses are not broken up into their
# user and @domain constituent parts, nor is user+foo broken
# up into user and foo.
#
# Results are the same as with indexed file lookups.
#
# BUGS
# The table format does not understand quoting conventions.
#
# CONFIGURATION PARAMETERS
# The following main.cf parameters are especially relevant
# to this topic. See the Postfix main.cf file for syntax
# details and for default values. Use the "postfix reload"
# command after a configuration change.
#
# virtual_alias_maps ($virtual_maps)
# Optional lookup tables that alias specific mail
# addresses or domains to other local or remote
# addresses.
#
# virtual_alias_domains ($virtual_alias_maps)
# Postfix is the final destination for the specified
# list of virtual alias domains, that is, domains for
# which all addresses are aliased to addresses in
# other local or remote domains.
#
# propagate_unmatched_extensions (canonical, virtual)
# What address lookup tables copy an address exten-
# sion from the lookup key to the lookup result.
#
# Other parameters of interest:
#
# inet_interfaces (all)
# The network interface addresses that this mail sys-
# tem receives mail on.
#
# mydestination ($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 "-".
#
# 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.
#
# SEE ALSO
# cleanup(8), canonicalize and enqueue mail
# postmap(1), Postfix lookup table manager
# postconf(5), configuration parameters
# canonical(5), canonical address mapping
#
# README FILES
# Use "postconf readme_directory" or "postconf html_direc-
# tory" to locate this information.
# ADDRESS_REWRITING_README, address rewriting guide
# DATABASE_README, Postfix lookup table overview
# VIRTUAL_README, domain hosting 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
#
# VIRTUAL(5)