If you're having trouble with your Microsoft Outlook data file, the Inbox Repair Tool (Scanpst.exe) can help you diagnose and repair any issues. This tool is designed to help repair issues associated with Personal Folders (.pst) files. Depending on your operating system, the steps to access the repair tool may vary. To use the Inbox Repair Tool, select Browse to select the Outlook data file (.pst).
Then choose Start to begin the scan. If errors are found, select Repair to start the process of correcting them. You can also choose to back up the scanned file before repairing it in case something happens during the repair process. If you're unable to start the Inbox Repair Tool automatically or manually, you can try to repair the Office application.
After pressing the Repair button, the actual repair process will start and go through all 8 phases again. If you still receive repair prompts after a successful repair, it is possible that the registry key “PromptRepair” was not deleted after repair.If Outlook works fine but you can't send or receive messages, you can use the Inbox Repair Tool to repair Outlook. If you're unable to access the pst file in Outlook and it can't be repaired with the Inbox Repair Tool, you'll need to restore it from a backup or use a third-party recovery tool.To repair your Outlook application with Microsoft Support and Recovery Assistant, download and install Microsoft Support and Recovery and then launch the Outlook and Repair Wizard.