Download the OST to MBOX Converter tool for Copy OST file to Thunderbird. Users can work Offline Data files of Outlook to MBOX tool for Copy OST files to Thunderbird. This software provides a free Demo edition that allows for users can migrate 20 OST files into MBOX. OST to MBOX Converter Tool maintain the all email Content formatting, attachment, header section, during the process to Copy OST file to Thunderbird. .