Don’t fret during conversion from OST files to PST files, as MS Outlook is widely used across the world but there are limitation also like its Outlook mailbox get corrupted and become inaccessible due to various reasons, OST files are prone to corruption and its recovery becomes very crucial task if you don’t have any knowledge regarding this field then don’t follow manual traditional task because it will require some technical knowledge, so the best way to get back entire database is using ATS OST to PST Converter which can be beneficial for you because it purposefully designed to recover the Outlook mailbox data, it can save the result in various interesting formats such as EML, EMLX, vCard, vCal, MSG, and MBOX, HTML. Also, the wonderful thing is that it supports Office 365 & Live Exchange Server so the user can migrate the OST files into each of it.
More Info: https://apps.microsoft.com/detail/9nnnf8gm49cm?hl=en-US&gl=US