The most powerful and secure solution is EmailsGuru OST to PST Converter tool. It is dedicated tool to convert OST files to PST format including emails, contacts, calendars, notes, tasks, journals and all other items. This tool protects all data integrity and email formatting throughout the conversion process. It has the capability to convert any size or corrupted OST files to Outlook PST format. Using this tool, you can also easily move OST files to Outlook 2019, 2016, 2013 and all below versions. Users can smoothly run this tool on any Windows supported platform. It is best email management tool for all users, who use Microsoft Outlook as their email client.
For more info- https://www.emailsguru.com/ost/pst/