Since there are many ways to convert an OST file to a PST file but using IT professionals suggested EmailsGuru OST to PST converter application is the best option. This tool is especially developed to quickly convert OST files to PST files without causing any corruption or data loss. It is dedicated to convert any size of OST file to PST format with all data including emails, contacts, calendars, notes and all other items. It is completely professional way to convert OST file to PST format in Outlook 2019, 2016, 2013 and all below versions. It also offers a trial version to all new users.