Rejecting Unknown Local Recipients with Postfix
As of Postfix version 2.0, the Postfix SMTP server rejects mail
for unknown recipients in
local domains (domains that match
mydestination or the IP addresses in $
proxy_interfaces) with "User unknown in local recipient table".
This feature was optional with earlier Postfix versions.
The good news is that this keeps undeliverable mail out of your
queue, so that your mail queue is not clogged up with undeliverable
The bad news is that it may cause mail to be rejected when you
upgrade from a Postfix system that was not configured to reject
mail for unknown local recipients.
This document describes what steps are needed in order to reject
unknown local recipients correctly.