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Re: How do you stop outgoing spam?

  • From: Scott Francis
  • Date: Tue Sep 17 13:56:39 2002

On Tue, Sep 10, 2002 at 08:10:46AM -0400, Marshall Eubanks
<[email protected]> replied to Iljitsch van Beijnum <[email protected]>:
[snip]
> > > When I go to Internet cafe's (I like Global Gossip), I connect my Ti-book
> > > to the local ethernet if at all possible (that's why I like Global Gossip)
> > > and use high bit rates (i.e., file transfers) in both direction.
> > 
> > Would the uploads be HTTP? That's the only thing I'd want to limit to a
> > few kbps. (Well, and outgoing SMTP to 0 kbps.)
> 
> When I am at a cafe I use a web based encrypted email program, and
> if I email a large attachment (say a pdf file), then it goes http outbound.
> The other major outbound bandwidth use is scp (very rarely, ftp or ssh).
> 
> I do not really see what the touch typing limit is relevant to - whose primary
> Internet use is telnet /ssh now-a-days ?

I'd estimate that my time is divided between SSH sessions (maybe 75%) and
everything else ( mostly web browsing instant messaging (more text)), with
music streaming generally going on in the background fairly constantly.

YMMV - but text is pretty far from dead. :) On the other hand, I'm pretty far
removed from (not to mention vastly outnumbered by) your average
AOL-subscribing casual Net surfer.

The OP was asking for solutions to blocking outbound spam. The most apparent
(to me, anyway) is to rate-limit SMTP (or deny SMTP to dialup/dynamic
addresses altogether; I have yet to see a convincing argument for allowing
dialup users to run SMTP servers at this point in time). While that may take
care of relay raping, there's still the HTTP problem to contend with
(although I bet it's considerably less of a problem).

I would imagine a traffic analysis of a spammer using HTTP and casual surfing
(or even large file transfers) would reveal some pretty significant
differences that could be used to implement some shaping or rate-limiting.

> Again, when I go to a cafe in another city, I am generally there to
> get some work done, and frequently have a bunch of previously prepared
> files to send. I may not be a typical user...

Me neither. :) Hopefully this discussion is proving useful to the OP.
-- 
-= Scott Francis || darkuncle (at) darkuncle (dot) net =-
  GPG key CB33CCA7 has been revoked; I am now 5537F527
        illum oportet crescere me autem minui

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