Justin Lloyd asked:
What is the best way to have Postfix silently drop emails to a specific invalid domain?
For reasons that cannot be handled otherwise right now, our mail servers receive a lot of emails for addresses of form $userid@BLAH, where @BLAH is always that value and $userid is programmatically-generated by the sender. The sender mail servers are allowed to relay through our mail servers but since BLAH is not a valid domain, the messages get deferred with “Host or domain name not found. Name service error for name=BLAH type=MX: Host not found, try again”. Obviously header_checks doesn’t work since that’s handled well after the hostname lookup.
I’d like to prevent these from ever getting to the queue, even though they do eventually age out after a few retries, and just silently discard them instead. (Eventually we’ll get the source issue resolved but that may not be any time soon.)
First, you’ll need to accept mail for the nonexistent domain, e.g. by adding it to
Then you’ll need to make a catchall address in
virtual_mailbox_maps that delivers it locally, for example:
Last you need to make a local alias for
/etc/aliases that delivers mail to
Postmap and reload postfix as appropriate.
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.