You can check the location of your Outlook Data flush DNS and re-sync Outlook Files in Outlook.

Repair Outlook Data Files (.pst and .ost)

An Outlook data files are designed to safely handle max space 50GB in Outlook 2010 to 2019 and Office 365 by default. You can try syncing outlook file 6 to 12 months or through archiving email using retention policy, could be a better way to protect the .ost size from corrupt. As it is converted, you can easily view the contents of the data file.

Outlook - OST file recurring corruption

Although the repair process might recreate some of the folders, they may be empty. The Fix Outlook and Office365 Sync Issues Lost and Found folder contains any folders and items recovered by the repair tool that Outlook can't place in their original structure. You can use the Inbox Repair tool (SCANPST.EXE) to diagnose and repair errors in your Outlook data file.

• If you know the location, click on the "Add File" tab and browse it.
• When the case comes to rebuilding the OST file, there are several things to look out for.
• You must re-select "Account Settings" when it opens across a drop-down menu.
• Find the .ost file that the error message reported to have errors, and then delete it and open outlook, it will recreate a new .ost file.

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

Fwiw, responding to my original post and how we addressed it for this user - we ended up creating new Outlook profile and limiting the amount of cached mail to 2 years. If the OST still gets corrupted when you have reduced the size there is something in the mailbox causing the problem. You must re-select "Account Settings" when it opens across a drop-down menu. There, lead into the "Data Files" tab and select your OST file. After selecting the file, click on "Open File Location" to redirect to the folder.

Method 4: Use OST Repair Tool

In certain cases, you must go for other methods to recover the data across OST files. If the respective file is not rebuilding from the above methods, there are other ways to get its data. This can be done with the help of PST files, another Outlook data file form. While they act as the basic backup data file for the user, the OST file Outlook Profile Repair And Recovery Steps can be easily converted to this form. Also, I forgot to mention that normally when the OST is corrupted you normally delete the file and recreate it.