Read, view, open, save the files on winmail.dat attachments. Easy-to-use. Graphic interface (no command-line tool). And FREE! Winmail.dat files are sent by the MS Outlook and users that use other e-mail clients cannot see them. General usage 1. Save the winmail.dat on your disk. 2. Open the "Winmail Reader" application. 3. Press the button "Open winmail.dat" and select the saved file. On Thunderbird 1. Select to open the winmail.dat attachment (double-clicking on it for instance). On the first time only: 1. Choose the Open with option and then press Browse... 2. Select the WinmailReader.exe file (should be on the "Program Files\Winmail Reader folder"). 3. Select the option "Do this automatically for files..." The next time you have only to choose the Open option for the Winmail.dat files!