Yes! You can convert Outlook OST file using vMail OST Converter Tools. you can read more information about how to convert Outlook OST to PST, EML, MSG, MBOX, PDF, Gmail and Migrate Outlook Messages into Office 365 Account.
https://www.vsoftware.org/help/ost-to-pst/how-to-works-ost-to-pst-converter.html
https://www.vsoftware.org/help/ost-to-pst/how-to-works-ost-to-pst-converter.html
