[cobalt-developers] slow reverse lookups in sendmail

[Dan Keller <dan@xxxxxxxxxx>]

Hello Cobalt gurus --

Any sendmail experts out there?

I'm running a RaQ2 with all the updates.
I believe that the current RaQ2 sendmail is
version 8.9.3 (true?)

My sendmail is having trouble receiving messages
from some of its mail server counterparts because
it responds slowly and sometimes they timeout.

I suspect that the slow response is due to the
spam-suppressing reverse server name lookup --
my server accepts no connections from servers
whose names it can't resolve.

This is the correct behavior.  The trouble is that
it takes too long to do the lookup even of remote
hosts whose names do resolve.

Acording to the doc at sendmail.org, the default
timeout.ident was dropped from 30 seconds to 5
seconds starting with version 8.5.

My sendmail.cf contains this line:

#O Timeout.ident=30s

which, as you can see, is commented-out so I presume 
that it's defaulting to 5 seconds.

Can you suggest what else I might check or tweak?

Many thanks for sharing your wisdom!

Dan Keller
dan@xxxxxxxxxx
http://www.keller.com/
+1 415 861-4500 (voice)
+1 415 861-4593 (fax)