Winmail.dat Reader is a free program for opening winmail.dat files. Sometimes it happens that emails with attachments that came to the mail instead of the attached document have an unknown winmail.dat file. It is a kind of archive into which the Microsoft Outlook mail client packages attachments, often Rich Text Format .RTF documents, but there can also be any other objects (images, music, spreadsheets and so on).
Working with the utility will not cause any problems: after opening a file, its contents will be displayed as a list in a special area, if you hover the cursor over any item in the list, its contents will be displayed on the right side of the window. Content can be opened in an external editor or viewer, or saved immediately in the format in which it was attached to the e-mail.
If desired, you can set up the association of winmail.dat files with the program.