If you have an orphaned or corrupted OST file then EdbMails OST Recovery tool that Convert OST file to PST is exactly what you need. Retrieve all OST contents including attachments, all email properties like cc, bcc, to/from address with just a few click using EdbMails.

Some of the reasons for OST corruption can be:

Network issues leading to synchronisation errors
System failure
Abrupt termination of Outlook
Virus or other such malicious infection

Feature of the OST Recovery tool from EdbMails include:
Repair corrupted OST file and convert it to PST.
Maintains the Folder structure intact.
All the data such as inbox items, sent items, contacts etc will be recovered.
No limitation to the size of OST file that can be recovered.
OST viewer to preview all OST data.
Free version of the tool to test out all its features and export upto 30 items per mailbox/folder.

to know more:OST to PST Converter