What are winmail.dat files?
Winmail.dat and/or application/ms-tnef files are sent by Windows users of Outlook or Exchange who have their mail clients set up to use ‘RTF’ instead of plain text or HTML. Usually they only contain a styled text version of the message you have just read in plain text, but they can contain encoded attachments that you can’t usually get to. TNEF’s Enough, by Josh Jacob, allows you to extract and read these files and attachments. Better still, contact your correspondent and ask them to reset their mail format from the (MS proprietary) “Rich Text” to either “Plain Text” or “HTML. If they have you in their Outlook Address Book they can make a setting to always send you Plain Text automatically. See also Microsoft KB: How to Prevent the Winmail.
