|GENERIC(5)||File Formats Manual||GENERIC(5)|
postmap /etc/postfix/generic postmap -q "string" /etc/postfix/generic postmap -q - /etc/postfix/generic <inputfile
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 regular-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".
- 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 logical line.
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 $proxy_interfaces.
- @domain address
- Replace other addresses in domain by address. This form has the lowest precedence.
- When the result has the form @otherdomain, the result becomes the same user in otherdomain.
- When "append_at_myorigin=yes", append "@$myorigin" to addresses without "@domain".
- When "append_dot_mydomain=yes", append ".$mydomain" to addresses without ".domain".
The propagate_unmatched_extensions parameter controls whether an unmatched address extension (+foo) is propagated to the result of table lookup.
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.
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.
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.
/etc/postfix/main.cf: smtp_generic_maps = hash:/etc/postfix/generic /etc/postfix/generic: firstname.lastname@example.org email@example.com firstname.lastname@example.org email@example.com @localdomain.local firstname.lastname@example.orgExecute the command "postmap /etc/postfix/generic" whenever the table is changed. Instead of hash, some systems use dbm database files. To find out what tables your system supports use the command "postconf -m".
The table format does not understand quoting conventions.
- Address mapping lookup table for envelope and header sender and recipient addresses while delivering mail via SMTP.
- A list of address rewriting or forwarding mechanisms 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:
- The network interface addresses that this system receives mail on. You need to stop and start Postfix when this parameter changes.
- Other interfaces that this machine receives mail on by way of a proxy agent or network address translator.
- List of domains that this mail system considers local.
- The domain that is appended to locally-posted mail.
- Give special treatment to owner-xxx and xxx-request addresses.
postmap(1), Postfix lookup table manager postconf(5), configuration parameters smtp(8), Postfix SMTP client
ADDRESS_REWRITING_README, address rewriting guide DATABASE_README, Postfix lookup table overview STANDARD_CONFIGURATION_README, configuration examples
A genericstable feature appears in the Sendmail MTA.
This feature is available in Postfix 2.2 and later.
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