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List:       qmail
Subject:    Re: greylite
From:       Markus Stumpf <lists-qmail () maexotic ! de>
Date:       2008-03-11 20:56:17
Message-ID: 20080311205617.GB89668 () server ! thinkof ! de
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On Tue, Mar 11, 2008 at 05:10:34PM +0100, Bernhard Graf wrote:
> ... and BTW
> http://www.heise-online.co.uk/news/Spammers-outwit-Google-s-captchas--/110286

This has no effect on the greylister, as the spammers will use the
Google mailservers and thus the mails will come from a legit mailserver
and legit mailservers will always bypass the greylister (which is why
greylisting works).

Greylisting only works for "mailservers" that have a "fire and forget"
strategy for mail delivery.

When I implemented greylisting for a ISP we used a rather huge whitelist
of mailservers constructed from logfiles for the start and added hosts to
the whitelist later with information from the whitelist database. This
way one can easily construct a list of legit mailservers for which
greylisting the traffic (for new triples) is simply an annoyance only.

	\Maex
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