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Re: [Asrg] attention bonds, was Email Postage

2008-11-30 16:52:54
On Sun, Nov 30, 2008 at 14:41, Rich Kulawiec <rsk(_at_)gsp(_dot_)org> wrote:

On Sun, Nov 30, 2008 at 11:55:43AM -0600, mathew wrote:
Not "all" technical solutions have been eliminated, just some.

Describe one which hasn't?

Okay, here's one.

Netflow and similar analysis.  An end-user system which emits an average
of 10 messages/day or makes an average of 10 outbound TCP conections/day
to port 25 which is now observed emitting 5000 messages/hour or making
5000 connections/hour is, at minimum, suspect.  It would probably be
appropriate to throttle this (either at the TCP connection level or in the
outbound MTA, as applicable) to at least minimize impact while buying time
to alert a human.  Rate-limiting like this doesn't stop all spam outright,
but it stops some spam (and stops it at the source) while providing the
opportunity to stop more.


Aren't ISPs already doing that, though?

And of course, spammers will just move to ISPs which aren't.

So it may not be eliminated, but I question whether it counts as a solution
to anything.


mathew
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