What is winmail.dat?Up to Table of Contents
When you receive an attachment from a person using Microsoft Outlook for their e-mail client, it may arrive as a file called "winmail.dat" instead of the PDF, DOC or whatever you were expecting. This is a "feature" of Outlook for other Outlook users, and must be remedied by a change on their Outlook. Send them an email with the following link.
Microsoft Support Article
Opening the Winmail.dat
To decode the file, you can use WMDecode, available here:
Unzipping WMDecode.zip will get you WMDecode.exe. Save your winmail.dat file somewhere useful, then drag it over the WMDecode.exe file. It will decode winmail.dat and save the decoded file in the same directory as you saved the winmail.dat. Your decoded file should have the proper name and file extension.