Postfix generic configuration example for CentOS Linux 8

Get the default configuration file generic for Postfix, optimized for CentOS Linux 8. 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)

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