[100381] in North American Network Operators' Group
Re: Misguided SPAM Filtering techniques
daemon@ATHENA.MIT.EDU (Sean Figgins)
Mon Oct 22 18:43:38 2007
Date: Mon, 22 Oct 2007 16:28:37 -0600
From: Sean Figgins <sean@labrats.us>
To: nanog list <nanog@nanog.org>
In-Reply-To: <C3425057.148239%dave.nanog@alfordmedia.com>
Errors-To: owner-nanog@merit.edu
Dave Pooser wrote:
> I call BS. I ran sender-callout verification on my primary email server for
> a while (before I became convinced it was mildly abusive, and stopped) and
> typically blocked 2-3 spams per day. In fact, I had more FPs than legit spam
> blocked by that method.
2-3 spams a day? That's really an amazing low number. You can call BS all you
want. I'll stick to my numbers as they are what my reports were telling me. Is
it possible that the email address in question was listed somewhere on the list
that viruses used to send forged email more than other spammers? That's
completely possible. Still, my results are what I observed when I went looking
at the statistics over a 6 month period. I was actually looking for other
statistics, the reduction in overall spam levels after implementing gray
listing, which was the next 6 month's statistics.
> Absolutely I am. If you're going to try to offload your spam filtering to
> me, I want the process to cause you as much pain as possible (within ethical
> limits, which is why I won't forward your email
It's OK, really, as I;m sure that your email address is only used once or twice
total, so your validation of the email address really means nothing to the
recipient. They get one spam message. If they get more, they just blacklist
the address. It's what I do.
> Sender callouts will verify addresses without requiring any action from the
> end user. If you must [ab]use my resources to do your job, please have the
> common decency to use my (abundant) hardware and software resources rather
> than my (much more limited) wetware resources.
You have more information on this? I'd be more than happy to investigate
another method myself that does not piss you off so much, as long as it provides
the same level of isolating spam.
-Sean
(Please respond only to the list)