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Re: Sub domains

2004-08-19 08:23:13
On Thu, Aug 19, 2004 at 05:18:39PM +0200, Koen Martens wrote:
On Thu, Aug 19, 2004 at 08:11:25AM -0700, Mark C. Langston wrote:
On Thu, Aug 19, 2004 at 10:16:46AM +0200, Koen Martens wrote:

Interresting question. I think proponents would say something like 'if
the second would send spam the isp example.com would get a bad
reputation, no problem: a just switches isp'. In reality, if a has no
choice, a is just doomed or has to find another way to send his mail,
using third-party services.


Unless the reputation service is capable of more fine-toothed decisions
than just using the domain name (e.g., GOSSiP).

But how to decided how fine-toothed the decisions should be? If the decision
is always based on subdomains, then spammer.com just sends his first spam-run 
from 1.spammer.com, the 2nd from 2.spammer.com, etc.. 

Use something other than just the domain name as the identity on which
reputations are built.  E.g., RFC2821 MAIL FROM: and sender IP address
combined.

-- 
Mark C. Langston            GOSSiP Project          Sr. Unix SysAdmin
mark(_at_)bitshift(_dot_)org   http://sufficiently-advanced.net    
mark(_at_)seti(_dot_)org
Systems & Network Admin      Distributed               SETI Institute
http://bitshift.org       E-mail Reputation       http://www.seti.org


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