Re: is reverse dns required? (policy question)

On Wed, 01 Dec 2004 13:16:49 EST, Steven Champeon said:

FWIW, 40% or more of the inbound spam mail here comes from hosts with a generic rDNS naming convention (even after DNSBLs and other obvious forgery checks such as hosts using my domain(s)/IP(s) in HELO/EHLO). We simply quarantine any mail from hosts without rDNS at all, and reject all mail from non-whitelisted generic hosts.

Any issues with dealing with the distinction between (for instance) FOO.generic.BAR.(com|net|org) (where generic is the 3rd level) and FOO.generic.BAR.co.uk (where it's a level further down)? Similarly, do you just treat all of *.info or *.biz as a generic swamp? Any other TLD-related issues you've identified in counting up that 40%?