Peter Smith wrote: > I'm interested in filtering mail relayed from hosts which have no reverse > dns (PTR) record. A lot of MTAs support rejection of mail from such hosts, > but I feel this will reject too much genuine mail, so I'm looking to > approach the problem via Spam Assassin - perhaps score 1 or 2 for such mail. > > I was suprised that Spam Assassin doesn't already have a rule for this, or > that a plugin has not been written; or perhaps I'm looking in the wrong > place? I'm aware of the tests Spam Assassin performs for PRT records for > hotmail, excite, mail.com etc, but there don't seem to be any general rules.
Take a look at Botnet plugin: http://permalink.gmane.org/gmane.mail.spam.spamassassin.general/93141 with minor changes I think it can do exactly what you describe, which is a subset of what it already does. -- René Berber
