Re: [Exim] FW: Defending Against Rumplestiltskin Attacks???

Top Page
Delete this message
Reply to this message
Author: Matthew Byng-Maddick
Date:  
To: exim-users
Subject: Re: [Exim] FW: Defending Against Rumplestiltskin Attacks???
On Thu, May 13, 2004 at 10:27:23AM +0100, Ian A B Eiloart wrote:
> Wouldn't you have to be prescient to delay *before* detecting the spam?


I delay on the basis of errors, such as recipients who are non-deliverable
but have high spam count. Bad HELO names, unverifiable MAIL FROM, being on
an RBL, looking like a dialup incur other penalties.

But after final dot a delay is either useless (as a connection drop has to
be treated as a timeout, and hence the message will be delivered anyway, if
it was going to be, if it wasn't, you weren't going to deliver it anyway,
so you might as well just reject) or will cause a duplicate delivery. Th
delay is useless, because it doesn't stop your spammer giving up before
he's tried to deliver the message - he's already delivered it.

MBM

--
Matthew Byng-Maddick          <mbm@???>           http://colondot.net/
                      (Please use this address to reply)