I would like to suggest a commercial solution like OST to PST Converter Software. This tool export OST items like emails, contacts, journals, notes, etc. The application additionally supports any kind of corrupted OST file and restores the recovered data into multiple file formats. Refer:- https://www.softakensoftware.com/ost-to-pst-converter.html
Free Outlook OST to PST Converter to fix corrupted Outlook OST file. Along with its tool to Convert file/folder from damaged OST to PST file by using batch option. Its app to conversion ost file to pst file with +20 file formats such as- pst file, Office 365 account, pst file, EML, EMLX, MSG, HTML, MHTML, MBOX, VCF, CSV, ICS, Live, Exchange Server, Zimbra, Gmail, Yahoo, and etc.
free unlimited ost to pst converter