[SURBL-Discuss] Subdomains in SURBL

Brandon Hutchinson hutchib at cscoe.accenture.com
Fri May 12 16:59:57 CEST 2006


Hello,

Looking at the multi.surbl.org zone yesterday, I noticed approximately 373 
subdomains in the list.

Here are a few examples:

www.fcudwedenagov.com
www.freecat.biz
www.hesvlabean.com
www.hterrani.com
ms7.pptel.net
msn.41m.com
mwetillf.iscool.net
mx.servebbs.net
mx2.dynu.net
www.yelvertonstores.co.uk

Looking at http://www.surbl.org/implementation.html item 2, do these 
subdomains belong in the list?

"Extract base (registrar) domains from those URIs. This includes removing any 
and all leading host names, subdomains, www., randomized subdomains, etc. In 
order to determine the base domain it may be necessary to use a table of 
country code TLDs (ccTLDs) such as this partially-complete one SURBL uses. 
(Note that this file is only rarely updated. Please don't download it 
frequently.) For example, any domain found in the two level ccTLD list should 
have a three-level domain name extracted (like foo.co.uk) for matching 
against a SURBL. Domains not specifically on the two level ccTLD list (such 
as foo.com or foo.fr) should be checked at two levels."

I believe SpamAssassin's URIDNSBL reduces the URIs to the base domain (e.g. 
example.com, example.co.uk), so if it encountered "www.freecat.biz," for 
example, it would lookup freecat.biz, which is not in the list.

Besides URIDNSBL, are there other URI lookup implementations for which it 
makes sense to include subdomains?

Thanks!

Brandon


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