CANONICALSection: File Formats (5)
CANONICALSection: File Formats (5)
postmap /etc/postfix/canonical postmap -q "string" /etc/postfix/canonical postmap -q - /etc/postfix/canonical <inputfile
Normally, the canonical 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 in order to rebuild the indexed file after changing the 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 regular-expression map where patterns are given as regular expressions, or lookups can be directed to TCP-based server. In that case, the lookups are done in a slightly different way as described below under "REGULAR EXPRESSION TABLES" and "TCP-BASED TABLES".
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 input format for the postmap(1) command is as follows:
With lookups from indexed files such as DB or DBM, or from networked tables such as NIS, LDAP or SQL, patterns are tried in the order as listed below:
This is useful to clean up addresses produced by legacy mail systems. It can also be used to produce Firstname.Lastname style addresses, but see below for a simpler solution.
This form is useful for replacing login names by Firstname.Lastname.
When a mail address localpart contains the optional recipient delimiter (e.g., user+foo@domain), the lookup order becomes: user+foo@domain, user@domain, user+foo, user, and @domain.
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 table, until a pattern is found that matches the search string.
This section describes how the table lookups change when lookups are directed to a TCP-based server. For a description of the TCP client/server lookup protocol, see tcp_table(5). This feature is not available in Postfix version 2.1.
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.
The following main.cf parameters are especially relevant. The text below provides only a parameter summary. See postconf(5) for more details including examples.
Other parameters of interest:
cleanup(8), canonicalize and enqueue mail postmap(1), Postfix lookup table manager postconf(5), configuration parameters virtual(5), virtual aliasing
Use "postconf readme_directory" or "postconf html_directory" to locate this information.
DATABASE_README, Postfix lookup table overview ADDRESS_REWRITING_README, address rewriting guide
The Secure Mailer license must be distributed with this software.
Wietse Venema IBM T.J. Watson Research P.O. Box 704 Yorktown Heights, NY 10598, USA