Some Microsoft Outlook users still send out attachment renamed to „winmail.dat“. The file allows Outlook users to send Transport Neutral Encapsulation Format (TNEF) information along with the email so that it retains the look and feel of the document with formatting, fonts, and colors when its received by another Microsoft Outlook user.
Unfortunately, the file is only relevant and used by Microsoft Outlook. Users of Lotus Notes, Mozilla Thunderbird or even Outlook Express will receive the attachment called winmail.dat with the email. The file is attached to the email because the original sender is sending emails in Microsoft Outlook Rich Text Format instead of Plain Text format.
I tried to explain this to many Outlook users who sent emails to me. Its not a big thing to prevent Outlook converting the messages. But Outlook users obviously do not want to deal with the application preferences. And Microsoft still believes everybody is using Outlook.
I will stop explaining this to my beloved Outlook friends from now on. I just installed Fentun. Fetun opens winmail.dat and extracts the attachment – to realize finally: most of the attachments are irrelevant.