On Thu, Apr 24, 2008 at 09:17:50AM -0400, Morris, Roy wrote:
> Yes, thanks I have stats running on the DNS server and dedicated bind
> server on each mail machine, which I would have thought plenty of horse
> power.
Okay, then maybe it's not DNS. The next step might be to check your
sendmail logs to see if you're bumping into various configurable
limits. There are quite a few of them; common ones (using sendmail
config file nomenclature) are:
BAD_RCPT_THROTTLE
CONNECTION_RATE_THROTTLE
MAX_DAEMON_CHILDREN
QUEUE_LA
DELAY_LA
REFUSE_LA
Most of these are probably not in play (e.g. BAD_RCPT_THROTTLE tends
to only kick in if you're getting dictionary-attacked) but it's possible
that one of the load-average-sensitive limits (_LA) is, or perhaps the
process limit is. This is of course another shot-in-the-dark guess,
so it may well be wrong too. ;-)
---Rsk
