The most likely solution to convert OST file to PST is EmailsGuru OST to PST Converter. It is specialized tool to convert OST file to PST with all data including emails, contacts, calendars, notes, task and all other items. This tool does not only convert OST to PST but also ensure all data integrity, email formatting, preserving attachments and meta data throughout the conversion process. Moreover, it recovers corrupted or damaged OST files. It is fully compatible with MS Outlook as well as Exchange Server. This software seamlessly works on all versions of Windows Operating Systems and offers a free trial version to all users.