[Mailman-Users] Mailman and spam

[Brad Knowles]

At 10:17 AM +0900 2005-04-21, Stephen J. Turnbull wrote:

>  Is this necessarily true?  On some systems (my lists' host, for one),
>  the dominating cost of spam is network bandwidth.  Disk I/O and CPU
>  are way behind.  So yes, if we can stop spam before we see the
>  content, we win big.  But as I understand it, even sendmail milters
>  read the whole message before making a decision.  So our costs remain
>  basically the same as long as the spam is caught somewhere in the
>  pipeline.

	You can't figure out what is spam and what isn't without scanning 
the content.  You're going to pay that network cost, period.  In my 
experience, the biggest cost is disk I/O operations in processing 
that message -- which is where sendmail+milter can be a huge win over 
other solutions which write the message to a temporary file and then 
pass that on to another program.

>  Am I missing something?  I agree that every list admin should consider
>  what they can do to reject spam as early in the pipeline as possible,
>  but even in the case of counting Spamassassin ****s one might want to
>  configure different lists differently.

	The earlier you can make decisions as to whether or not to throw 
something away, the better.  If you have to wait until the message 
gets to Mailman, you may be limited in terms of what you can do in 
order to deal with spam.  If you can deal with the spam earlier in 
the process, so much the better.

-- 
Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

   SAGE member since 1995.  See <http://www.sage.org/> for more info.