[luau] Blocking mail relayers

[Yuser]

Are you sure they are trying to relay or bounce mail from your server? 
Based on your commentsbelow about messages to: people and the passing of the relay tests it
appears this  might be anattempt to flood your mailserver with pseudo-random names trying to
actually find validusers to send spam to or collate a list of valid usernames at your domain.
 Either way I wouldwant them blocked.


> How can I be sure I'm not relaying for this scumball? How can I
just
> block  him completely?
>
> Are there any good test tools out there for making sure
I'm not letting
>  any scum get through?
>