Outlook 2001 Mac freezes


I have one computer that runs OS 10.3.9 and Outlook 2001 for Mac in Classic. This is an Exchange environment. Almost every morning when i start up Outlook, the application will freeze within the first 5 minutes usually when trying to read a new email or trying to compose a new email. If, I delete the "exchange preferences" file in the OS 9 system folder, this seems to cure the problem until the computer is shutdown at night and rebooted the next morning. What could be causing this???