> ...in a misguided attempt to filter out unsolicited mail, a number
> of people have started using MTAs which throw all the relevant
> RFCs out of the window and block incoming mail on new and exciting
> criteria, such as 'can I reverse lookup the name of the sending MTA.'

Reverse lookups on the sending site do give you a FQDN to complain to.
Without that you can't easily write a perl script to fire off a spam
complaint to the spammer's ISP.

Grep your 'Received' lines sometime and see if you don't notice a
strong correlation between folks having screwed-up or non-populated
DNS zones and other lossages that attract spammers.

-wolfgang
-- 
       Wolfgang Rupprecht <wolfgang+gnus@dailyplanet.wsrcc.com>
		    http://www.wsrcc.com/wolfgang/
Coming soon: GPS mapping tools for Open Systems. http://www.gnomad-mapping.com/