procmail
[Top] [All Lists]

Re: What is the most efficient way to query an RBL?

2004-05-24 06:40:43
Michelle Konzack wrote on Mon, 24 May 2004 11:21:34 +0200:

My new (since 20.05.2004) FileServer is a Duron 1600 with 128MByte and 
I have around 8000 Mails per day which are preprocessed by procmail 
(looking vor binary attachments and run f-prot) and spamassassin. 
The mailsystem is a courier-(mta,imap,mlm,webadmin) 
 
Curently I have attached a sbl-xbl/rbl filter AFTER spamassassin and I 
get one or two messages per day in its SPAMHAUS-folder.


You do know that procmail + SA doesn't scale very well? Using a milter or 
MailScanner to invoke SA is much more efficient if your daily email gets 
in the thousands. I also always recommend to use RBLs right at MTA level. 
If you use the right ones (and that includes Spamhaus, but using 20 RBLs 
is overkill) your false positive level is nearly zero and you block a lot 
of spam and most virus mail at the MTA. This means less processing cost 
(only the remaining stuff has to be scanned) and less traffic (because you 
don't get the DATA portion). We reject about 80% of all incoming mails 
with RBLs at MTA level and get almost no viruses sent to us. The false 
positive rate is something like 1 in 10.000 or 100.000.


Kai

-- 

Kai Schätzl, Berlin, Germany
Get your web at Conactive Internet Services: http://www.conactive.com
IE-Center: http://ie5.de & http://msie.winware.org




_______________________________________________
procmail mailing list
procmail(_at_)lists(_dot_)RWTH-Aachen(_dot_)DE
http://MailMan.RWTH-Aachen.DE/mailman/listinfo/procmail