vMail OST to PST Converter - vSoftware OST to PST is an useful app that is able to execute email conversion from offline. OST to Outlook. PST format. This tool has very easy to use interface with lots of features. V software OST to PST converter can convert OST file to PST format very as well as many other formats like MBOX, EML, MSG, vCal, EMLX and vCard formats. Features include Converts. OST to. PST formats Simple user interface MS Office 2016, 2013, 2010 and more supported Overall, vSoftware OST to PST is a very capable option when looking for a lightweight and simple OST to PST converter.