I'm in the process of migrating an existing mail setup from Exim to Postfix, which involves multiple virtual domains (i.e. they're not tied to the machine name or local system accounts).
I've come across a few entries in
/etc/aliases which look like this:
aliasname: :fail: Failure message
If I email
email@example.com I get a bounce with
550: Failure message. Effectively these aliases are addresses which are no longer used but provide a slightly more useful error message instead of just deleting the alias.
Is there equivalent functionality available for Postfix?