Although the repair process might recreate some of the folders, they may be empty. The 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. The Inbox Repair tool checks the Outlook data files on your computer to see if they're in good shape.

Outlook - Corrupt OST

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 Outlook Login Issues Troubleshooting 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. When Outlook is running and is halted in such a way, it can damage the OST file.

How to recover OST files

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

• Also, I forgot to mention that normally when the OST is corrupted you normally delete the file and recreate it.
• In certain cases, you must go for other methods to recover the data across OST files.
• If you're using an Exchange email account, you can delete the offline Outlook Data File (.ost) and Outlook will recreate the offline Outlook Data File (.ost) the next time you open Outlook.
• Although the procedure may differ to some extent, it can be executed.
• You can check the location of your Outlook Data Files in Outlook.
• Thus, you need to have a good anti-virus system to protect your computer.
• When Outlook is running and is halted in such a way, it can damage the OST file.

How to Fix Corrupted OST Files

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 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. I’ve used the repair tool when this started and it did not really repair the file. I used the following combination of techniques to get the user working. In the Folder Pane, you might see a folder named Recovered Personal Folders that contains your default Outlook folders or a Lost and Found folder.

Part 3: How to Rebuild OST Files?

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. 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.

Repair an Outlook data file (.pst) file

The first solid question that comes to mind is whether OST files are rebuildable. We are aware that OST files are directly connected to the Outlook email. The mailbox not updating on IMAP question mentioned above is thus definite in such a case.



Thus, you need to have a good anti-virus system to protect your computer. Find solutions to common problems or get help from a support agent. To the ones that said 50Gb are more than enough for most people,… well we are in 2020 & I can assure you that more than half of the accounts we manage are way above 50Gb, close to 100Gb actually.



You might be working on something important across it when it Troubleshoot Office 365 Sync and Login Issues happens. As you said Outlook E3 licenses should support at least 100GB of data & there’s no excuse why it can’t support OSTs above 50GB when they offer twice that space. In addition, you could open outlook in safe mode, maybe some add-ins affect the outlook. You could Right-click the Start button, and click Run, type Outlook.exe /safe, and click OK. This article offers to rebuild the OST file without putting you in any difficulty.

You can create a new Outlook Data File and drag the items in the Lost and Found folder into the new data file. After you've moved all the items, you can remove the Recovered Personal Folders (.pst) file, including the Lost and Found folder. To create a new Outlook Data File, go to Create an Outlook Data File. If you're using an Exchange email account, you can delete the offline Outlook Data File (.ost) and Outlook will recreate the offline Outlook Data File (.ost) the next time you open Outlook.