Sometimes - either for work or
leisure - I need to configure Linux servers, and also mail servers.
postfix is a great software that I like to use for mailservers; in this post I want to describe you one feature that works in a counter-intuitive way.
In postfix you can define mailboxes by specifying in your /etc/postfix/main.cf:
virtual_mailbox_maps = hash:/etc/postfix/virtual_mailbox_maps
Official virtual MAILBOX example here
You can also specify aliases, e.g. mailboxes that directly forward to other mailboxes, by specifying:
virtual_alias_maps = hash:/etc/postfix/virtual_alias_maps
Official virtual ALIAS example here
Aliases are useful for example when you want to define a catch-all alias forwarding all mail to the postmaster address.
Priority matters!
However, what I dislike is the priority applied to both: aliases have higher priority than mailbox maps (yes,
you've read right).
The first time I configured an alias I got all mail delivered to the catch-all address because I thought that - being less catchy - the catch-all addresses would have less priority.
What you need to do is instead add identity definitions to the aliases map, this way:
john@example.com john@example.com
mary@example.com mary@example.com
berry@example.com berry@example.com
@example.com postmaster@example.com
In above example of
virtual_alias_maps, the last line is the catch-all line, while the other lines are inherent to mailbox maps defined in
virtual_mailbox_maps.
Now tell me if that's not counter-intuitive, error-prone (because of the duplication) and less easy to mantain.
