Download this SysInspire OST to PST Converter if you are unable to access MS OST Outlook. This Microsoft software allows you to access your MS Outlook and recover your existing data in a matter of seconds, and it is the ideal option for OST Conversion because it allows you to convert an OST file to a PST file for free, among other formats. MBOX, EML, MSG, EMLX, Yahoo, Gmail, Zimbra, HTML, ICS, vCard, vCal, and Office 365 are examples of file formats. It allows you to save all MS Outlook versions, including 2010, 2007, 2013, 2016, and many others. Download a free trial version of the software.