Let's know How to Convert Exchange OST Mailbox into PST, EML, MSG file format With this OST Mailbox into PST Converter tool, MS Outlook users can convert all items of Outlook like journals, calendar, to-do list, contacts, appointment, emails, contact information, etc. OST recovery software are the simple way to recover & repair OST file & convert OST file of any exchange versions including MS Exchange (5.0 / 5.5 / 2000 / 2003 / 2007 & 2010).