Winmail DAT File Viewer is the easiest, fastest, most reliable way to extract, view, and save the contents of winmail.dat, msg, xps files. You may receive winmail.dat files from the senders who are using Microsoft Outlook (1997, 2000, 2003, 2007, 2010). Winmail.dat contains all attachments and rich text message, and not all e-mail clients can recognize its format.It is the solution.