CANONICAL(5) CANONICAL(5) NAME canonical - format of Postfix canonical table SYNOPSIS postmap /etc/postfix/canonical DESCRIPTION The optional canonical file specifies an address mapping for local and non-local addresses. The mapping is used by the cleanup(8) daemon. The address mapping is recursive. The file 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. After an update it may take a minute or so before the change becomes visible. Issue a postfix reload command to eliminate the delay. The canonical 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). Think Sendmail rule set S3, if you like. Typically, one would use the canonical table to replace login names by Firstname.Lastname, or to clean up addresses produced by legacy mail systems. The canonical mapping is not to be confused with virtual domain support. Use the virtual(5) map for that purpose. The canonical mapping is not to be confused with local aliasing. Use the aliases(5) map for that purpose. The format of the canonical table is as follows, mappings being tried in the order as listed in this manual page: blanks and comments Blank lines are ignored, as are lines beginning with `#'. user@domain address user@domain is replaced by address. This form has the highest precedence. This form 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 user@site is replaced by address when site is equal to $myorigin, when site is listed in $mydestina- tion, or when it is listed in $inet_interfaces. 1 CANONICAL(5) CANONICAL(5) This form is useful for replacing login names by Firstname.Lastname. @domain address Every address in domain is replaced by address. This form has the lowest precedence. In all the above forms, when address has the form @other- domain, the result is the same user in otherdomain. ADDRESS EXTENSION When table lookup fails, and the address localpart con- tains the optional recipient delimiter (e.g., user+foo@domain), the search is repeated for the unex- tended address (e.g. user@domain), and the unmatched extension is propagated to the result of table lookup. The matching order is: user+foo@domain, user@domain, user+foo, user, and @domain. 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. canonical_maps List of canonical mapping tables. recipient_canonical_maps Address mapping lookup table for envelope and header recipient addresses. sender_canonical_maps Address mapping lookup table for envelope and header sender addresses. Other parameters of interest: inet_interfaces The network interface addresses that this system receives mail on. masquerade_domains List of domains that hide their subdomain struc- ture. masquerade_exceptions List of user names that are not subject to address masquerading. 2 CANONICAL(5) CANONICAL(5) 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 cleanup(8) canonicalize and enqueue mail postmap(1) create mapping table virtual(5) virtual domain mapping 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 3