Get the default configuration file generic for Postfix, optimized for Alpine Linux v3. This example configuration ensures optimal compatibility and performance for Postfix, making it easy to set up and adjust to meet your needs.
Find and download the configuration file here: /etc/postfix/generic.
For more configurations and setup guides, visit our related files section to further customize your system.
# GENERIC(5) GENERIC(5)
#
# NAME
# generic - Postfix generic table format
#
# SYNOPSIS
# postmap /etc/postfix/generic
#
# postmap -q "string" /etc/postfix/generic
#
# postmap -q - /etc/postfix/generic <inputfile
#
# DESCRIPTION
# The optional generic(5) table specifies an address mapping
# that applies when mail is delivered. This is the opposite
# of canonical(5) mapping, which applies when mail is
# received.
#
# Typically, one would use the generic(5) table on a system
# that does not have a valid Internet domain name and that
# uses something like localdomain.local instead. The
# generic(5) table is then used by the smtp(8) client to
# transform local mail addresses into valid Internet mail
# addresses when mail has to be sent across the Internet.
# See the EXAMPLE section at the end of this document.
#
# The generic(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).
#
# Normally, the generic(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/generic" 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 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 result
# When pattern matches a mail address, replace it by
# the corresponding result.
#
# 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.
#
# 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
# $proxy_interfaces.
#
# @domain address
# Replace other addresses in domain by address. This
# form has the lowest precedence.
#
# RESULT ADDRESS REWRITING
# The lookup result is subject to address rewriting:
#
# o When the result has the form @otherdomain, the
# result becomes the same user in otherdomain.
#
# o When "append_at_myorigin=yes", append "@$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.
#
# EXAMPLE
# The following shows a generic mapping with an indexed
# file. When mail is sent to a remote host via SMTP, this
# replaces his@localdomain.local by his ISP mail address,
# replaces her@localdomain.local by her ISP mail address,
# and replaces other local addresses by his ISP account,
# with an address extension of +local (this example assumes
# that the ISP supports "+" style address extensions).
#
# /etc/postfix/main.cf:
# smtp_generic_maps = hash:/etc/postfix/generic
#
# /etc/postfix/generic:
# his@localdomain.local hisaccount@hisisp.example
# her@localdomain.local heraccount@herisp.example
# @localdomain.local hisaccount+local@hisisp.example
#
# Execute the command "postmap /etc/postfix/generic" when-
# ever the table is changed. Instead of hash, some systems
# use dbm database files. To find out what tables your sys-
# tem supports use the command "postconf -m".
#
# 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.
#
# smtp_generic_maps
# Address mapping lookup table for envelope and
# header sender and recipient addresses while deliv-
# ering mail via SMTP.
#
# propagate_unmatched_extensions
# A list of address rewriting or forwarding mecha-
# nisms that propagate an address extension from the
# original address to the result. Specify zero or
# more of canonical, virtual, alias, forward,
# include, or generic.
#
# Other parameters of interest:
#
# inet_interfaces
# The network interface addresses that this system
# receives mail on. You need to stop and start Post-
# fix when this parameter changes.
#
# proxy_interfaces
# Other interfaces that this machine receives mail on
# by way of a proxy agent or network address transla-
# tor.
#
# mydestination
# List of domains that this mail system considers
# local.
#
# myorigin
# The domain that is appended to locally-posted mail.
#
# owner_request_special
# Give special treatment to owner-xxx and xxx-request
# addresses.
#
# SEE ALSO
# postmap(1), Postfix lookup table manager
# postconf(5), configuration parameters
# smtp(8), Postfix SMTP client
#
# 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
# STANDARD_CONFIGURATION_README, configuration examples
#
# LICENSE
# The Secure Mailer license must be distributed with this
# software.
#
# HISTORY
# A genericstable feature appears in the Sendmail MTA.
#
# This feature is available in Postfix 2.2 and later.
#
# 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
#
# GENERIC(5)
Download the raw file with wget or curl
wget -O generic.example https://exampleconfig.com/static/raw/postfix/alpine3/etc/postfix/generic
curl https://exampleconfig.com/static/raw/postfix/alpine3/etc/postfix/generic > generic.example
Other config files you might find useful