>1.  I want to totally reject any mail that is not addressed to an  
>account on sims - how do i do that?

As long as you don't have an account called "Unknown", this should happen
automatically.

Also, if you have something in your router along the lines of
*@domain.com = local.account, then any address for domain.com will be
accepted and routed to the local.account specified.

That does the same thing as having an Unknown account, but does it on a
per domain basis instead of server wide.

If you are currently accepting all email addresses, check to see if you
have one or both of the above in your setup.

-chris
<http://www.mythtech.net>