[76100] in North American Network Operators' Group
Re: is reverse dns required? (policy question)
daemon@ATHENA.MIT.EDU (Valdis.Kletnieks@vt.edu)
Wed Dec 1 14:41:34 2004
To: Steven Champeon <schampeo@hesketh.com>
Cc: nanog@merit.edu
In-Reply-To: Your message of "Wed, 01 Dec 2004 13:16:49 EST."
<20041201181649.GA31174@hesketh.com>
From: Valdis.Kletnieks@vt.edu
Date: Wed, 01 Dec 2004 14:41:00 -0500
Errors-To: owner-nanog-outgoing@merit.edu
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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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