If you desire to search for the most trustworthy way to convert or recover the OST data to PST. I would advise trying, the third-party tool Shoviv OST to PST converter. It provides the safest error-free conversion and converts the multiplied OST data to Outlook PST, Office 365, Live Exchange Server with any intrusion, and saves OST data to EML, MSG, and HTML formats. It recovers the lastingly deleted OST items and restores the unavailable data. it supports all versions of Outlook and Windows OS. It provides the free trial version which provides the ability to convert the first 50 items per folder.

More details, visit:- Convert OST to PST