Winmail.dat opener will help you to extract files and messages with all attributes from Winmail.dat files. Open an app and choose the file using the system's default picker, no permissions are required. Winmail.dat or in other words TNEF is Microsoft proprietary file format designed for Outlook and Exchange Server attachments. Winmail.dat extractor uses two methods of TNEF file parsing that guarantee the successful result of the work. Winmail.dat extractor does not require any permissions for its work and can't touch any of your data, only the one you personally choose to.