reject mail from user@mydomain.tld if not SASL or mynetworks?

[Tomasz Chmielewski]

From time to time, I receive spam from someu...@mydomain.tld, sent from 
some exotic part of the world.

I would like to reject the mail from all @mydomain.tld addresses if it's 
not:

- sent from mynetworks
- sent using SASL auth


Is it possible?


--
Tomasz Chmielewski
http://wpkg.org