If you want the easy solution for converting OST file to PST Outlook file format. Then I suggest you download Free OST to PST Migration software. It can very easily convert all multiple emails format, subfolders, email properties attachments, mailbox items like - calendar, contact, inbox items, outbox items, task, draft, journal, etc. It can recover all corrupted OST file to PST Outlook data without any issues facing. It supports all MS Outlook version like:- 2003, 2007, 2010, 2013, 2016, 2019 etc.
More Info:- https://www.softakensoftware.com/ost...converter.html