What is this winmail.dat file?
Many times you might receive an email with an attachment called
winmail.dat. The file is sent from people using Microsoft Outlook as
their email program. 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 Outlook Express, Eudora, Netscape Messenger, and other email
programs 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
How to Configure Outlook NOT to send Winmail.dat attachments
To Turn off Rich Text sending for messages in Microsoft Outlook
1) Click on Tools
2) Click Options, and then click the Mail Format tab.
3) In the Send in this Message Format list, select Plain Text, and then
This will set your default sending method to Plain Text, which will
lose your special formatting options with fonts, colors, etc. However
everyone, no matter what email program they are using, will now be able
to receive your email with no problems.
There is more information on this topic in the Microsoft
What if I Want to View the WinMail.dat file?
If you want to view the winmail.dat file and see the message, there are
programs that decode the file and allow you to view it. Listed below
you will find some of these programs.
Will work on Win9X, NT, and 2000 computers. But does not work on
Program using a simple drag and drop procedure to view winmail.dat
Macintosh program to decode winmail.dat TNEF attachments