Re: [Asrg] An Anti-Spam Heuristic
Barry Shein <bzs@world.std.com> Thu, 13 December 2012 22:53 UTC
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Cc: Barry Shein <bzs@world.std.com>
Subject: Re: [Asrg] An Anti-Spam Heuristic
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On December 13, 2012 at 09:21 mike@mtcc.com (Michael Thomas) wrote: > On 12/13/2012 09:16 AM, Barry Shein wrote: > > There's also Jef Poskanzer's greymilter which basically requires one > > re-send from each never before seen mail server not in a white list. > > > > And sendmail (and others') HELO delay (delay sending HELO a short > > period of time) and don't speak until you're spoken to whatever they > > call it (I use it, the sender must wait for the SMTP responses, can't > > just dump an SMTP conversation at you.) > > > > They're basically isomorphic to hashcash type solutions, increase the > > sender's cost, but very transparent and quite clever because of that. > > > Given botnets, anything that tries to shift burden back onto the > sender is not very likely to be effective in the long run. Yes, you > might get some short term relief, but the firehose is just a software > update away. Has this been measured (reference)? Or is this just one of those "truisms" that kick around here? I'm thinking that a spammer has to put out on the order of a billion messages (attempts) per day to be interesting. If you slowed those down that would be a blow to them, a billion times even a little is a lot. Sure, we can postulate infinite botted systems I suppose. But that's still just a wild guess. I'm not arguing for hashcash per se, I think it has other problems, but I also wonder if this counter-claim is really true. Or, put better, can we quantify it? -- -Barry Shein The World | bzs@TheWorld.com | http://www.TheWorld.com Purveyors to the Trade | Voice: 800-THE-WRLD | Dial-Up: US, PR, Canada Software Tool & Die | Public Access Internet | SINCE 1989 *oo*
- [Asrg] An Anti-Spam Heuristic Adam Sobieski
- Re: [Asrg] An Anti-Spam Heuristic Steve Atkins
- Re: [Asrg] An Anti-Spam Heuristic Barry Shein
- Re: [Asrg] An Anti-Spam Heuristic John Levine
- Re: [Asrg] An Anti-Spam Heuristic Adam Sobieski
- Re: [Asrg] An Anti-Spam Heuristic John Levine
- [Asrg] The Real Problem (was: An Anti-Spam Heuris… Andrew Sullivan
- Re: [Asrg] An Anti-Spam Heuristic Rich Kulawiec
- Re: [Asrg] An Anti-Spam Heuristic Bill Cole
- Re: [Asrg] An Anti-Spam Heuristic Bart Schaefer
- Re: [Asrg] The Real Problem Chris Lewis
- Re: [Asrg] The Real Problem Alessandro Vesely
- Re: [Asrg] An Anti-Spam Heuristic Barry Shein
- Re: [Asrg] An Anti-Spam Heuristic Michael Thomas
- Re: [Asrg] The Real Problem (was: An Anti-Spam He… Barry Shein
- Re: [Asrg] An Anti-Spam Heuristic Barry Shein
- Re: [Asrg] An Anti-Spam Heuristic John Leslie
- Re: [Asrg] An Anti-Spam Heuristic Seth
- Re: [Asrg] An Anti-Spam Heuristic Steve Atkins
- Re: [Asrg] An Anti-Spam Heuristic Barry Shein
- Re: [Asrg] An Anti-Spam Heuristic Steve Atkins
- Re: [Asrg] An Anti-Spam Heuristic Barry Shein
- Re: [Asrg] An Anti-Spam Heuristic Barry Shein
- Re: [Asrg] An Anti-Spam Heuristic Chris Lewis
- Re: [Asrg] An Anti-Spam Heuristic Barry Shein
- Re: [Asrg] An Anti-Spam Heuristic Michael Thomas
- Re: [Asrg] An Anti-Spam Heuristic Chris Lewis
- Re: [Asrg] An Anti-Spam Heuristic Chris Lewis
- [Asrg] Countering Botnets to Reduce Spam Adam Sobieski
- Re: [Asrg] Countering Botnets to Reduce Spam Chris Lewis
- Re: [Asrg] An Anti-Spam Heuristic Martijn Grooten
- Re: [Asrg] An Anti-Spam Heuristic Adam Sobieski
- Re: [Asrg] Countering Botnets to Reduce Spam Rich Kulawiec
- Re: [Asrg] Countering Botnets to Reduce Spam Adam Sobieski
- Re: [Asrg] Countering Botnets to Reduce Spam Chris Lewis
- Re: [Asrg] Countering Botnets to Reduce Spam Rich Kulawiec
- Re: [Asrg] An Anti-Spam Heuristic John Levine
- Re: [Asrg] An Anti-Spam Heuristic John Levine
- Re: [Asrg] Countering Botnets to Reduce Spam John Levine
- Re: [Asrg] An Anti-Spam Heuristic Chris Lewis
- Re: [Asrg] Countering Botnets to Reduce Spam Chris Lewis
- Re: [Asrg] Countering Botnets to Reduce Spam Chris Lewis
- Re: [Asrg] Countering Botnets to Reduce Spam Barry Shein
- Re: [Asrg] Countering Botnets to Reduce Spam Chris Lewis
- Re: [Asrg] An Anti-Spam Heuristic Alessandro Vesely
- Re: [Asrg] An Anti-Spam Heuristic Chris Lewis