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 resolve Outlook not sending emails fast 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 need the right tool that does not corrupt or damage the data in the process. Convert your OST to PST for optimal results if rebuilding the OST file does not do the trick. Further, the saved PST file could be accessed at any time by importing it in the Outlook profile. 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.

• 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.
• Outlook might be able to fix your file." Click OK to run the Inbox Repair Tool.
• 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?

If anyone can get an answer from microsoft on this issue I’d appreciate it. Any MS techs can contact me if they need further information or analysis. I’ve created a ticket today with Rackspace to see if their other customers are having this issue but I’m not hopeful on hearing back from them. Only way to restore Outlook 2016 (Windows) functionality was to create a new profile; this worked, and a new OST file was created.

Repair an Outlook data file (.pst) file

It is surely possible to rebuild the OST files solve Office 365 mailbox sync delays at any instant. Although the procedure may differ to some extent, it can be executed. This article will mention the process to rebuild the OST file in detail.



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 Outlook Login Issues Troubleshooting 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.