spam with bad From: field

From: "postmaster@coker.com.au" <ich@trimas.com.au> Above is the From field of a spam that recently arrived in my inbox, the Return-Path and Message-ID refer to trimas.com.au so it didn't hit any SPF checks. Is there a good way of stopping such spam with Postfix and SpamAssassin? I wrote some milter code to stop this for a client, the code was a little hacky and even if I had approval to reuse it the amount of work involved would vastly exceed the amount of time it takes to just delete such mail. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/