[exim] 5 Minute Penalty Box

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Author: Marc Perkel
Date:  
To: exim-users
Subject: [exim] 5 Minute Penalty Box
Trying a new trick to stop dictionary attacks where I'm looking at the
logs and seeing someone hitting the server over and over and getting
failed recipient responses.

So - after one attempted message to a failed recipient I add the from
address to a list and the next time I return a temporary error. The list
is cleared every 5 minutes so if someone sent something innocently -
they are only blocked for 5 minutes.

But - someone probing for email addresses only get to do it once every 5
minutes. All their other attempts are blocked.

Anyhow - I'm still experimenting with the verious penalty box ideas and
hoping to inspire others to get interested.

Penalty box is different than greylisting in that everyone is innocent
until proven guilty. They get one shot and if they sin - then they are
penalized for a period of time. The main focus are offenders who keep at
it and increase server load.

--
Marc Perkel - marc@???

Spam Filter: http://www.junkemailfilter.com
    My Blog: http://marc.perkel.com
My Religion: http://www.churchofreality.org
~ "If it's real - we believe in it!" ~