> In above example u can see in the 1st example the > sender(xyz) is not real user of my domain , still he > is able to sendmail to my real users (abhi). > > plz help me. abhishek singh, The simplest way that I can think of is to create a database of your addresses and then check the mail from against that database and reject if not found. The problem is how to maintain that database. You could add a table lookup for this database and then add rules in Local_check_mail to check mail from: addresses against the database.