We keep getting e-mail attachments in winmail.dat files and can’t open them. What’s going on? Is there a utility that can extract the attachments from these? When Outlook or Outlook Express users send ...

.dat can mean many things. data of any type quite often ends up with these extensions. How about using the app that created them? You can also try viewing them in notepad.

Windows associates data files with applications so that the appropriate program launches automatically when the icon or name of the data file is clicked. For example, if a GIF image is associated with ...

I was confused by your answer regarding winmail.dat. The file cannot be opened traditionally, at least to obtain what the receiver believes to be valuable contents. Rather, it’s used internally by ...