Postfix: Blocking inbound messages with fake addresses
I'd like to block inbound email messages that appear to be from our domain, but which are not in our password file.
For instance, suppose a message arrives from spammer (at) ourdomain.com, and we have no such user... that message should be rejected without further processing, since we know they cannot exist.
Is there a Postfix guru in the house who knows how to do this? Is it even possible without writing a plugin of some sort?
(I had to mangle the imaginary address to get the forum to let me post this.)