On Mon, 24 Sep 2007 11:26:49 EDT, "Durbin, Daniel R" said:

> Looking at our hourly delivery between 45,000-75,000 messages/hour and the =
> size of our mail queue which is frequently over 150,000,

The most critical thing here is probably *not* the total size of the queue, but
the number of different destinations represented.  150K mails that represent
30K mails queued to each of 5 places is a *totally* different beast than 150K
mails queued, 2 to each of 75K destinations. In particular, in the first case,
if the *first* mail times out trying to make a connection, you may as well just
bag it and retry in 10-30 minutes, rather than trying 29,999 more times. You
don't get that luxury for the second case, you have to try to make connections
75,000 times....