On noting patterns in spam attempts

[J C Lawrence]

On Sat, 26 Jul 2003 13:47:23 -0700 
Chuck Yerkes <chuck+baylisa at snew.com> wrote:

> I block them with a generic "header error" (I'm not here to make
> spammers smarter).  It can get 2-5% of all mail.

Exim has a non-default configuration option which will hard reject (at
the SMTP level) mail with illegal/improper headers.  It makes quite a
few checks and is quite effective at dropping your spam rate.

  Caveat: It also has the side effect of periodically
  unsubscribing/NOMAILing your Yahoo Groups/lists subscriptions as Yahoo
  sets NOMAIL on the first hard bounce.  In every case where I've chased
  this down (roughly 15 of them), it has been due to an RFC2822
  violating spam forwarded thru a Yahoo list which was then bounced by
  Exim.  

-- 
J C Lawrence                
---------(*)                Satan, oscillate my metallic sonatas. 
claw at kanga.nu               He lived as a devil, eh?		  
http://www.kanga.nu/~claw/  Evil is a name of a foeman, as I live.