[NCLUG] anti-spam warfare

[Mike Loseke]

Thus spake Craig, Mike:
> 
> 
> 
> >  For some reason, my three-letter domain name (swo.com) tends to get alot
> > of spam for non-existent users. I'm assuming it's because of folks just
> > typing in garbage when they don't want to give their real email.
> > 
> >  I have a minimal filter in place which sends an error message to the
> > sender but I get a bounce if (when) the sender's email doesn't exist. I
> > just envisioned a filter which holds the "enemy" MTA hostage while
> > it figures out whether or not the sender exists and then releases the
> > hostage afterwards - maybe an hour or two if the sender doesn't exist.
> > 
> >  I'm not in a MTA mood at the moment so I'm just thought I'd throw this
> > out
> > and see what the masses think. :-)
> > 
> Heheh...  You have an evil mind, Mike.  I *like* that.  :)
> 
> The idea of "holding the MTA hostage" is intriguing.  Have you any thoughts
> on how that might be accomplished?  <g>
> 
> OTOH, I suspect that tactic might be of questionable legality,
> unfortunately; it seems that it could possibly be construed as a DOS attack.
> (ObDisclaimer: IANAL.)  

 I think that some disclaimer within the error message to the effect that
"every effort will be made to ensure proper and complete delivery to either
the intended recipient or, in the event that there is no such local user,
the sender, blah blah blah ..." would be adequate. Unfortunately we live in
the united states of litigation and just breathing someone elses air is
grounds for a suit.

 Of course, running all of this on a 286 with a small bit of RAM might
be able to accomplish the same thing. "What? Your mail server has been
talking to mine for three hours trying to deliver the same message? Hmm,
that machine is pretty old - give a few more and maybe it will get around
to it."

 Maybe holding them hostage long enough to check if it's valid or not, then
just not accepting the message for delivery if the return is bad - maybe by
closing the connection prematurely forcing it to get requeued on their end
in an infinite loop. Hmm...

-- 
   Mike Loseke    | ... Logically incoherent, semantically
 mike at verinet.com | incomprehensible, and legally ... impeccable!