You have an anti-virus program that isn't working correctly. You have defective add-ons within your Outlook application, There are multiple users trying to access the PST file Malware has wormed its way into your PST file You had a storage device failure or there are bad sectors where the PST file is stored There are issues with your network connection These reasons can be any of the following. The Microsoft Outlook application can get stuck on processing for numerous reasons, but it almost always has to do with a corrupted PST file. 1 8 Reasons Behind Outlook Stuck on Processing Issue
