How do I repair an inaccessible OST file in Outlook 365?

sanjaykumar210

Repairing an inaccessible OST file in Outlook 365 usually starts with identifying whether the problem is caused by synchronization issues, profile corruption, or damage within the OST file itself. Many users first try simple methods like restarting Outlook, creating a new Outlook profile, or recreating the OST file. These steps can sometimes fix minor issues, but they may not help if the OST file is heavily corrupted or contains mailbox data that is no longer available on the server.

One user experienced this problem after Outlook 365 stopped syncing suddenly during a network interruption. The OST file became inaccessible, and Outlook kept showing errors while opening the mailbox. Since the file contained years of important emails and attachments, deleting it was not a safe option. They used the SysInfo OST Recovery Tool to repair the damaged OST file. The software scanned the inaccessible mailbox using its Advanced Recovery mode and restored emails, calendars, contacts, notes, and tasks without affecting the original data.