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 guide to Office 365 sign-in errors 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.

• Outlook 2016 connecting to Office 365 E3, mailbox size ~55GB and Outlook reghack effected to allow for ~80GB OST.
• Virus attacks can directly attack the OST file, which would disrupt its data.
• 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.
• It is surely possible to rebuild the OST files at any instant.
• Only way to restore Outlook 2016 (Windows) functionality was to create a new profile; this worked, and a new OST file was created.
• You can use the Inbox Repair tool (SCANPST.EXE) to diagnose and repair errors in your Outlook data file.

How to Fix Corrupted OST Files

Perfectly repair and recover corrupted Outlook PST & OST files. 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.

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 Exchange connectivity diagnostic 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.

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

Even with the reg hack in place, I’ve found that ost files over 50gb tend to corrupt and become unusable with regularity. OST file corruption is a common problem faced by Outlook users like you. While you seek to counter this problem, you look for effective techniques. Although there are many methods to try, a few are productive. One such method is to rebuild the OST file across Outlook. The functionality is diverse, and it can be approached in multiple directions.



You might be working on something important across it when it Outlook Stuck on Synchronizing Folders 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.

On the next screen, access the "Find File" option if you are unaware of the location. If you know the location, click on the "Add File" tab and browse it. Malware or virus attacks can cause great havoc across the computer. Every important data and detail might be damaged due to it. Virus attacks can directly attack the OST file, which would disrupt its data.