The WebbyAcad OST Recovery Tool offers advanced features to fix damaged OST files and convert them to PST, EML, MSG and other formats while preserving folder hierarchy and metadata. It supports all Outlook versions and has no file size limitations, making it a comprehensive solution for recovering inaccessible OST data. Change the Outlook sync settings to only keep a limited amount of mail off-line. If you only keep 6 or 12 months offline that will reduce the OST size significantly. This is all most people will need, searching for older items will be slower but for daily use items it will still be quick. As you close them, lead to the folder and right-click on the OST file.

I can't repair corrupted Outlook .ost file

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.

Part 1: Can OST Files Be Rebuild?

I have 2 computers and both have been facing the same issue. You can check the location of your Outlook Data Files in Fix Outlook Not Opening After Windows Update Outlook.

Method 3: Convert OST to PST

You might be working on something Outlook Not Sending or Receiving Email important across it when it 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. Refer to this blog Solutions To Fix Error – "Errors Have Been Detected In The File Xxx.Ost" Solutions To Fix Error – "Errors Have Been Detected In The File Xxx.Ost" for the solution to this OST error. This article offers to rebuild the OST file without putting you in any difficulty.

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

There may be items in the backup file that you might be able to recover that the repair corrupted OST in Outlook Inbox Repair tool couldn't. 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.

Method 1: Deleting Outlook OST File and Recreating It

• If the OST still gets corrupted when you have reduced the size there is something in the mailbox causing the problem.
• On the next screen, access the "Find File" option if you are unaware of the location.
• The Lost and Found folder contains any folders and items recovered by the repair tool that Outlook can't place in their original structure.
• If you can open the original Outlook Data File, you might be able to recover additional items.
• I’ve used the repair tool when this started and it did not really repair the file.
• 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.
• We will help our readers decide the best way to rebuild OST for functioning through Outlook.
• You could Right-click the Start button, and click Run, type Outlook.exe /safe, and click OK.
• You surely won't be disappointed with the results of rebuilding OST.

As you change the extension, relaunch Outlook to rebuild your OST 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 question mentioned above is thus definite in such a case.

Additional resources

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. The functionality is diverse, and it can be approached in multiple directions. When the case comes to rebuilding the OST file, there are several things to look out for.