Just open your browser and go to winmaildat.com. It's a straightforward website that lets you upload and open DAT files without needing to sign up or provide an email.

What is the deal with those winmail. dat files? I get them in my email all the time, and nothing seems to be able to open them.

Q. I received e-mail from a relative that says it is in a winmail.dat file. When I try to open the file, I get a message that says something like: "You are attempting to open a dat file. They are ...