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 - 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 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.
• 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

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.





It is surely possible to rebuild the OST files Outlook profile repair and recovery steps 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

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 modern authentication 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.