Re: [Asrg] An Anti-Spam Heuristic

"John Levine" <johnl@taugh.com> Sat, 15 December 2012 01:12 UTC

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Date: 15 Dec 2012 01:11:54 -0000
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From: "John Levine" <johnl@taugh.com>
To: asrg@irtf.org
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Subject: Re: [Asrg] An Anti-Spam Heuristic
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>They don't implement RFCs accurately because they're trying to send
>faster/cheaper.

Actually, a lot of it is still because they're sloppy and inept.  Not
all spammers are stupid, but a lot of them are.  This one, for example
(I know, I was there):

http://www.justice.gov/usao/nj/Press/files/Rad,%20Christopher%20Verdict%20PR.html

>Even e-bay for example had a problem when this "demand they wait for a
>response" feature started to become popular because they too figured
>out they could just dump one side of the SMTP conversation w/o waiting
>for responses and it previously worked well enough and was much
>"cheaper" on their servers.

That was just broken.  There's a perfectly well specified way to do
SMTP pipelining, which lets clients skip most of the waits without
losing the responses.

R's,
John