[Mimedefang] Fw: [Asrg] user-level blacklisting patented

[Joseph Brennan]

--On Wednesday, March 16, 2005 15:10 -0600 Chris Myers 
<chris at by-design.net> wrote:

> As posted to the (moribund) IETF Anti-Spam Research Group mailing list.


See http://www.titankey.com.

The web pages are disappointingly full of marketing hype.  According
to this, no other product provides for rejecting mail during the smtp
conversation, and spammers usually remove addresses when they get a
550 response.  I say disappointingly because it does seem to have
some interesting features.

Whitelists per user are probably prior art even in 2000.  This however
filters not only per user but per full address using something akin to
plus addressing (the example given uses "dot addressing").  The
whitelist itself is built not only from direct user input but also
from watching outgoing mail and possibly other methods (alluded to but
not detailed).  For non-whitelisted addresses the response can be either
plain reject or challenge-response.

The host running the database has to see all mail in and out.  I didn't
notice anything about replication and scaling.

How's that again: "we've got > 8000 end-users on it with > 2M emails/day
passing through our software" ... that's an average 250/day per user,
which is about ten times what we have per user.

Joseph Brennan
Academic Technologies Group, Academic Information Systems (AcIS)
Columbia University in the City of New York