MS Outlook creates a mailbox which holds all the attachments and emails in various folders. To store mailbox data there are two types of files used on your local drive – Offline Storage Table (OST) file and other is Personal Storage Table (PST) file. You should use OST file to configure Outlook in offline mode. In OST file, all the offline work is store and synced with Exchange Server when it is connected to the internet.
Sometimes, it shows the following synchronization error –
Unable to expand the folder. There are errors in xxxx.ost file. The folders couldn’t be opened. Quit all the mailbox applications and use Inbox Repair tool.
If you get this type of error, there must be a problem in your OST file and it couldn’t get synced properly with Exchange Server. Some of the common reasons of OST file corruption are –
- Exchange Server crash
- Virus attack in OST file
- Exchange Server Database Corruption
- Mailbox deleted from Exchange Server
How to Fix?
As discussed in the error message, quit all the applications which might be using OST file.
- Retrieve the repaired items.
- Repair OST file by running scanpst.exe (Inbox Repair Tool).
- Find OST file
In some cases, Inbox Repair Tool doesn’t repair OST file because this tool is not sufficient in complex scenarios of corruption in OST file. If it is not working, it is better to use OST Recovery tool for OST to PST file conversion. These tools can convert the files even in severe cases of OST corruption and recover all the OST file components, such as emails, contacts, attachments, notes, tasks, calendar entries, etc. After getting converted PST file, it can be saved to any storage media or disk and open it with Outlook directly.
Good thing about this software is that, you can use Free trial version. Free trial version will show you all the recoverable emails in preview items, where you can check your desire emails. And allow you to save some emails in Free version.