The migration of Exchange OST file to PST file is easy if you use MVP recommended VSPL OST to PST Converter utility. This OST to PST Converter utility has a preview facility that shows the scan mailbox and all the mailbox data such as email, draft, task, attachment, notes, contact, sent item, delete an item, calendar, etc.
Apart from PST, users can move OST to Office 365 with the help of this utility. Furthermore, this utility can maintain folder hierarchy, and there is no chance of data loss.
Through the aid of this program, users can export their data into multiple file formats such as PST, EML, MSG, EMLX, and HTML. Furthermore, it allows you to select only the data you want to export from the OST file to the PST file