is reverse dns required? (policy question)

Valdis.Kletnieks at vt.edu Valdis.Kletnieks at vt.edu
Wed Dec 1 19:41:00 UTC 2004


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%?

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