OSTtoPSTAPP OST to PST Converter is used to transfer OST files to PST files. The best feature and functionality of this program allowed even inexperienced users to convert OST files to PST file format. OST files can be exported to the PST file format by using the batch conversion option. With the use of its program, corrupt Outlook OST data files can be converted to PST files, Office 365 accounts, EML, EMLX, MSG, HTML, MHTML, MBOX, VCF, CSV, ICS, Live, Exchange Server, Zimbra, Gmail, Yahoo, etc. Because there are no file size restrictions for conversion, you can use this converter tool to convert any size file without issue. You can use the software's demo version to convert selected OST files to PST file format for free.