I have an Exchange Server 2003 that will soon be put to rest, but I still have our company's CEO attached because of his blackberry connection. Soon I will migrate him over to our new Exchange 2010 server. I have noticed over the past couple of days that sometime during the middle of the night that the CPU usage spikes to 100% and the server is losing network connectivity. I have to shut down the server and then everything works fine with no issues until the next night. I am approaching the weekend and I will hate to have to do this first thing on Saturday and Sunday. I have looked in the event viewer and see nothing out of the ordinary. I did notice this morning that the store.exe was using a lot of memory, but after I reboot the server it goes back down. I have no idea why it started all of a sudden and I have no idea where to look to see what may be causing the issue.