Postfix/aliasing
user aliases
To set up aliases, either edit the file specified by the alias_maps setting in main.cf (/etc/aliases by default) and then run newaliases (or postalias /etc/aliases) to update the database, or else use Webmin (Servers → Postfix Mail Server → "Mail Aliases" icon → "Create a new alias" link).
There is also a /etc/postfix/virtual file for aliases in virtual domains; it can be edited manually, but you need to run postmap /etc/postfix/virtual after modifying it.
Notes:
- Webmin seems to automatically run newaliases when you add or modify an individual alias, but not when you use it to edit the /etc/aliases file directly. Changes made to /etc/aliases will not take effect until the database is updated.
- Stopping and starting the postfix daemon does not update from the aliases file; you still have to run newaliases.
- see aliases for more information.
virtual users
By default, virtual aliases seem to get looked up only when email comes from the outside; locally generated emails are "returned" as undeliverable with the error message "Diagnostic-Code: x-unix; user unknown"
The following change in main.cf solves that problem –
- change: receive_override_options = no_address_mappings
- to this: receive_override_options =
– but creates a new one, in that externally-sourced messages are now delivered twice (or four times if addressed directly to a virtual user instead of a virtual alias).
Someone who understands the internal structure of postfix could probably figure out what this means (and how to fix it), but I'm still working on it.
catch-all
To set up a catch-all address, edit main.cf and set the following parameters:
- local_recipient_maps =
- luser_relay = <whereToSend>
The syntax for whereToSend is explained here.
Examples:
luser_relay = $user@anotherdomain.org- forwards all email addressed to "invaliduser@firstdomain.org" to "invaliduser@anotherdomain.org"
luser_relay = youraccount@anotherdomain.org- forwards all email addressed to invalid users to "youraccount@anotherdomain.org".
This page mentions some other parameters but neglects the ones above.