We have some internal processes that send email to our Exchange 2003 system (on Win2K3 R2 32bit). Recently they have been intermittently failing with various errors -- boiled down they report "Exchange refused the connection". We use XWall as our spam filter (and XWall Filter for Outlook client integration) and it is also reporting "Connection closed for no reason" which could indicate that the Exchange server is having problems keeping up.
We only have about 25 user mailboxes (about 20-25GB total) and the CPU load on the machine is not pegged (it's a 8-core Dell w/4GB RAM). My guess is that it's I/O bound in some way. We get a metric ton of spams and my guess is the box can't keep up. How would I go about diagnosing this (user mailboxes are not reporting anything amiss)? What should I look at to see where the bottleneck is -- disk I/O? Network I/O? CPU? etc.? How do I tweak Exchange?
Yeah, I can look at Task Manager, but that's not really telling me anything. Thanks!!