[cobalt-users] blocking a specific email addy on 550

["Manny Tau" <mtau@xxxxxxx>]

On a 550, I want to reject emails from 1 particular email address, to 1
particular email account on the 550. I'd like the email to be rejected and
bounced back to the sender.

What's the simplest way of doing this?

I can put the email addy on spam assassin's black list, but I want the email
to bounce back to the sender...

thnx, Manny