We recently upgraded several users to Outlook 2000 and since their upgrade certain file attachments are being blocked by Outlook. These are the same files that they could open in Outlook 97. Some of the extensions for the blocked files are EXE andMDB. Outlook 2000 claims the files are unreliable are will not allow access to them. How can this be corrected short of deleting and re-installing Outlook 2000, and hoping for the best.