Recently I found it takes longer than before to connect Exchange server with outlook clients. Yesterday, it suddenly stopped response to any outlook clients. Then I check on server, it shows that the process STORE.EXE took 99% of CPU time. But when I check the application events I found nothing wrong suspecious. I am getting worried about the exchange server. any one kind enough inform me of what is the problem and what should I do in this case? We use exchange5.5 SP4, NT4 SP6a Thanks in advance!