Use an excellent and efficient CubexSoft OST to PST Converter application, which allows you to convert Outlook emails from OST storage files and migrate them directly to Outlook PST format. This OST to PST software is an advanced solution that instantly the OST to PST conversion process and makes it possible without Outlook application.  The software gives 100% accurate results to convert Offline OST data file to Outlook without any issue of data loss.