On Thu, 16 Dec 2004, Alan J. Flavell wrote:
>
> As a workaround, sure; but breaking a server is no long-term solution
> to broken clients.
I don't think there's much point in trying to fix the world :-)
People have tried to use technical competence as an anti-spam technique,
but it doesn't work because legitimate email senders are generally less
clueful than the spammers. However spammers do stupid things which allow
you to systematically identify some of their messages using technical
features. A double dot in a HELO name (which Exim's built-in syntax check
doesn't detect) or a very long HELO name are both very reliable indicators
of abusive behaviour. This kind of signature might be technical
incompetence (double dot) or it might just be abuse (excessive length) but
the point of the check is that it's spammer-only behaviour, and doesn't
overlap with the fumblings of idiots.
Tony.
--
<fanf@???> <dot@???>
http://dotat.at/ ${sg{\N${sg{\
N\}{([^N]*)(.)(.)(.*)}{\$1\$3\$2\$1\$3\n\$2\$3\$4\$3\n\$3\$2\$4}}\
\N}{([^N]*)(.)(.)(.*)}{\$1\$3\$2\$1\$3\n\$2\$3\$4\$3\n\$3\$2\$4}}
