Hii, DRS is very helpful to export the OST to Office 365 mailbox data. Users can easily download and run this tool. It supports all versions of Windows OS. Your OST mailbox data is restored to your Office 365 account by OST to Office 365 Migration Tool. It migrates your mailbox folders, such as inbox, outbox, sent, draft, calendar, contacts, journals, etc., without damaging their contents.