Microsoft Outlook Question:

When a user moves on, you should delete his or her .pst file from the local system, as follows:

Close Outlook if it's open.
From the Windows Start menu, choose Control Panel.
Double-click Mail.
Click Data Files.
Select Personal Folders and click Remove.
Click Close and close the Control Panel window.

Outlook needs a personal folder, so after deleting the current .pst file, create a new one by clicking Add. Be sure to set the new file as the default. Delete a user's .pst file only when you're certain that no one will need to access its contents.