You can convert OST files to PST format using the expert programme ZOOK OST to PST Converter. It allows you to retrieve your MS Outlook data, including attachments, emails, contacts, notes, and other data items, in Outlook. It simply works with all versions of Outlook, including Outlook 2021, 2019, 2016, 2013, and others, to convert an OST file to a PST file.

Download and use it now :- https://www.zooksoftware.com/ost-to-pst/