I have a mailrelay based on postfix working with amavisd-new and spamassassin on one of my clients. It simply works well. The problem is they want to block mails comming from hotmail, yahoo and gmail containing words like "Let's go destroy" for e.g.
I am trying something like proxysmtp but with no success. And based on the mail traffic, the machine will die.
Can you help me?