[Mimedefang] limiting SA's RBL timeouts

[Joseph Brennan]

--On Wednesday, January 11, 2006 19:53 -0800 Gary Funck <gary at intrepid.com> 
wrote:

>
> As a follow-up to the discussion regarding the fact that sendmail
> and spamassassin perform a lot of DNS lookups, one thing we do here
> to speed up SA a bit is to tell it to limit the time it waits for
> a response from a spam block list lookup.  We place the following
> in our local.cf file in SA's rules directory:
>
># limit RBL checking to max. 5 secs instead of default of 30
> rbl_timeout 5
>
> How much this improves things, I don't know.  It was suggested
> on the SA mailing list a while ago.


You could have Mimedefang do those lookups instead, early in the
process.  If you will reject for being in certain RBLs then you can
dispose of those messages without running the SA stuff.

Also, I think Spamassassin looks up all the IPs in the headers,
while Mimedefang can test just the IP relaying the mail.  In my
opinion this is more accurate as well as more efficient.

Joseph Brennan
Columbia University Information Technology