Despamming wholesale dialup

Fri Oct 30 18:28:28 UTC 1998

 NEW SOFTWARE, NOT CONGRESS MAY STOP SPAM
(Source: PC World Online) If you're sick of being deluged with
junk e-mail, don't look for relief from Congress, where only one
pending bill is even close to passage.
http://www.idg.net/go.cgi?id=34539

hmm this may be an option worth looking into....

Henry R. Linneweh

Bryan Bradsby wrote:

> On Fri, 30 Oct 1998, Phil Howard wrote:
>
> > These are actually two separate issues:
> >
> > 1.  Open SMTP relays
> >
> > 2.  Dialup ports open to all SMTP servers
> >
> > While these two issues do interact, and a perfect solution to one of them
> > makes the other much less of an impact, they do both need to be addressed
> > as distinct issues.
>
> Exactly.
>
> Attempting to assist responsible netops in closing their open relays
> addresses issue #1.  Send them a respectful, helpful and friendly note.
>
> I would like to discuss item #2. See below.
>
> > > But my question is - Would responsible netops be willing to give me a list
> > > of their (non-relaying) SMTP servers?
> >
> > I'm curious what such a list would be used for.  Would you limit access to
> > just those SMTP servers?
>
> Exactly. I would open up port 25 incoming for responsible (not an open
> relay) SMTP servers.  Thus real customers could send their legitmate mail.
>
> Block port 25 (only) from all "open modem banks" (TM) to my SMTP servers.
> If implemented on a large enough scale, the modem user will be
> 'encouraged' to use the SMTP server supplied with their account. Make each
> dialup customer go through, and be authenticated by their own SMTP server.
>
> Each OMB filter will most likely be a /24 or larger block of IP addresses.
>
> The logic is simple. There are more modems than SMTP servers. Block port
> 25 from the OMBs, open up for corresponding (responsible) SMTP servers.
>
> Either an operator directs (by filter) port 25 on his modem banks to his
> SMTP servers, (preventing OMB), or we do it for him.  The intent is a
> convergence on a suggested Best Practice.
>
> > Would that not form a rather long access list?
>
> Perhaps for a router or firewall, but not for a sendmail access.db.
>
> >  --    *-----------------------------*      Phil Howard KA9WGN       *    --
> >   --   | Inturnet, Inc.              | Director of Internet Services |   --
> >    --  | Business Internet Solutions |       eng at intur.net        |  --
> >     -- *-----------------------------*      philh at intur.net       * --
>
> -bryan
> abuse at capnet.state.tx.us

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