If you want to convert any micro soft ost file and not find any tool try stella
micro soft ost to pst converter tool to convert all ost mailbox items in to pst file this software is convert all corrupted and unmounted ost mailbox items in to pst file this software is convert all version 32bit and 64bit ost file this software is run all windows operating systems this software is convert all ost file items like emails, contacts, calendars, tasks, notes and many other items in to pst file. For more info visit this link
https://www.stelladatarecovery.com/ost-to-pst-recovery.html