How to prevent users from receiving email

[Bill Moran]

Apparently my memory is useless and I've lost the ability to use
google as well.

I just added a user account to a mail server, but I don't want that
user to receive mail on that server.  It's running Postfix.

I seem to remember a canonical method for preventing certain users
from receiving email.  But my memory has failed, and I can't seem
to find anything on google.

Is it an /etc/aliases trick?

-- 
Bill Moran

Many miles away, something crawls through the slime at the bottom of a
dark, Scottish lake.