Microsoft Outlook stores offline copies of your messages, contacts, notes and calendar events in a personal storage table file known as a PST. This file is critical in that it contains a backup of your Outlook account. If you switched email accounts, need to restore to a backup or just want to add an additional folder to help keep you better organized, you will need to add a PST file to Outlook to get your old information synced and up and running. Tips Writer Bio
