You can check the location of your Outlook Data you can check here Files in Outlook.

Repair Outlook Data Files (.pst and .ost)

This is all most people will need, searching for older items will be slower but for daily use items it will still be quick. As you close them, lead to the folder and right-click on the OST file. Once you re-open Outlook, your OST file is automatically recreated or rebuilt. If your hard drive goes through any physical damage, it will damage the data across it too. A bad sector or corrupted hard drive can cause OST inaccessibility.

Outlook - OST file recurring corruption

The functionality is diverse, and it can be approached in multiple directions. When the case comes to rebuilding the OST file, there are several things to look out for. If online Outlook email repair utility you can open the original Outlook Data File, you might be able to recover additional items. The Inbox Repair tool creates a backup file with the same name as the original, but with a .bak extension, and saves it in the same folder.

• Although there are many methods to try, a few are productive.
• The Lost and Found folder contains any folders and items recovered by the repair tool that Outlook can't place in their original structure.
• Any MS techs can contact me if they need further information or analysis.
• You might be working on something important across it when it happens.
• Only way to restore Outlook 2016 (Windows) functionality was to create a new profile; this worked, and a new OST file was created.

What are the major Reasons of OST Corruption and how to Fix it

Confirmed user can log on to OWA (Office 365 webmail) without issue. Upon starting Outlook, error message displayed is "Errors have been detected in the file ," then prompt appears to locate (not fix) the OST file. Outlook 2016 connecting to Office 365 E3, mailbox size ~55GB and Outlook reghack effected to allow for ~80GB OST. If your computer faces unnecessary power outages during a process, it can be damaging.

Method 4: Use OST Repair Tool

This article offers to rebuild the OST file without putting you in any difficulty. While this is an effective model, the discussion would revolve around all possibilities. We will help our readers decide the best way to rebuild OST for functioning through Outlook. Outlook Not Sending or Receiving Email For the past 2 weeks, the OST of my Desktop Outlook has been corrupting continuously. I have 2 computers and both have been facing the same issue.