Sometimes I just despise MS Exchange. While it can be a great business productivity tool, there are times that it causes more hassle than it's worth.
On Monday, my network admin informed me that the inetinfo.exe process of our Exchange server was eating up processor cycles. It was keeping our CPU processes usage in the 90-100% range. Now, inetinfo.exe is the Internet Information Server process. My network admin proceeded to look at IIS for the problem. However, Exchange sits on top of IIS and integrates with it. So I knew we were having an Exchange problem. We finally determined that our SMTP virtual server was the service causing the problem. We noticed a lot of stuff in the queues, so we cleared them out and things seemed fine.
On Tuesday, we begin to receive sporadic reports of emails to certain places bouncing back. Also, some email was coming in, but not everything that was expected. This sounds like a classic DNS problem. We fiddled around with DNS.
On Wed, no email was coming in. We could send internally and send to some places. We found that our SMTP port was "clogged." We had over 50,000 messages from outside domains sitting in our queue. This seemed weird because we are not an open relay. I had had a third party testing facility test us on Monday, because I thought that might be part of the problem and we had come back clean. The problem was, though, that we were allowing remote computers to connect, but not to send. Exchange, then, was getting bogged down trying to resend messages that it did not have permission to send. We would clear the queues, but they would almost instantly fill up again with these messages. Finally, we found out the proper steps to not allow for remote computers to connect at about 8:00 PM last night.
Things seem fine from home this morning. I am heading into work now to see if we finally really did fix the problems.
