Use CubexSoft OST to PST Converter Tool to directly convert OST to PST without Outlook. It is one of the best tools to bulk convert Outlook OST file to PST file format including all emails, contacts, calendars, and other items. This software allows you to convert selected OST file to PST format without Outlook. There is no file size limitation, one can export a large size of OST files into PST format without any data loss. During the process, the software keeps all the folder structures without any changes and data loss. This software supports various saving output option like Outlook PST, PDF, MBOX, EML, MSG, and other. It was workable on both Mac and Windows operating systems