In case of accidental deletion of OST file your Outlook mailbox files become orphaned and become useless, if you want to recover that database you can use any third party application and we personally recommend OST to PST Converter which is designed in the surveillance of professional team, the users can easily recover their data and convert into Outlook PST and other file formats such as MSG, HTML, vCal, vCard, MBOX, EML, and EMLX.
It is 100% safe and secure application that is designed with your necessity. By taking the help of this program you can export your password protected and encrypted file in a safe manner. This is the best application among the users due to its amazing features. The auto scanning of the utility scan the data and migrate them into Outlook PST.
To evaluate the working performance of this program you can download the free demo version that give permission to export 30 emails per folder free of cost.
Locate the ScanPST.exe file. The default location for this file is C:\Program Files (x86)\Microsoft Office\OfficeXX\SCANPST.EXE, where XX is the version number of your Office suite.
Double-click on the ScanPST.exe file to open it.
In the Inbox Repair Tool window, click on the Browse button and select the OST file that you want to repair.
Click on the Start button to begin the repair process.
The Inbox Repair Tool will scan the OST file for errors and attempt to repair them. If the repair process is successful, you will see a message that says "Repair complete".
Click on the OK button to close the Inbox Repair Tool.
Open Outlook and try to access your data. If the repair process is successful, you should be able to access your data without any problems.