An end to spam through Graphnet

DAVE NORDLUND nordlund at
Mon Aug 4 12:41:09 UTC 1997

> Date:          Fri, 01 Aug 1997 14:32:34 -0700 (PDT)
> From:          Geoff White <geoffw at>
> Subject:       Re: An end to spam through Graphnet
> To:            Dana Hudes <dhudes at>
> Cc:            nanog at

> On Fri, 1 Aug 1997, Dana Hudes wrote:
> > Hi folks,
> > Some time back before the latest round of cable cuts and BIND
> > arguments
> > you may recall that I notified everyone that Graphnet was being
> > abused to
> > transit spam. An ugly mess -- between the bounces and the flood
> > of 'remove' from
> yeah,
> 	I got hit the other day.
> > We have put an end to this madness on our systems by building and
> > configuring the very latest Sendmail v8 and BIND 4.9.6 (attempts
> > to use v8 failed for being too Berkley,
> > on a Solaris 2.x system -- but don't start arguing that here
> > please) in combination with
> > filters on our gateway router. Load has dropped way down on our
> > sparc20, and hopefully the spammers will go play with someone
> > else instead of futilely occupying bandwidth on our circuits .
> > 
> > Let this be an object lesson to those of you out there who have
> > yet to upgrade:
> > the spammers will find you sooner or later. They walk down every
> > A record in every zone until they find a victim. They look in
> > public databases like RIPE to see what mailboxes are registered
> > for the zone and they use those names to try to get past your
> > sendmail filters and launch spam in your name (doesn't work on
> > us, I thought of that trick).
> > So go forth to and and compile.
> Can anyone elaborate a little more on the "one true" set of procedures
> that one should take to prevent spammers from abusing ones resources.
> The current problem that I have is valid customers who are "on the road"
> and want to sendmail through my SMTP server when they dial into 
> att or netcom, before their eudora's used to point their SMTP server
> at me, that ain't happenin' after my spam attach so is there some work
> around that they can use?

Just get your customers to use an Email client that knows how to use MX
records and does not need a "forwarder"!  Frontier Technologies sells the
Super TCP/NFS suite with an Email client that works just fine.  It even
has internal IDs and Passwords so that more than one person (or you if
you have to look like more than one person) can use the same machine.


Dave Nordlund               d-nordlund at
University of Kansas        913/864-0450
Computing Services          FAX 913/864-0485
Lawrence, KS  66045         KANREN

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