* Dr. Internet columnist Steve Blass offers advice on how to open winmail.dat files We keep getting e-mail attachments in winmail.dat files, and can’t open them. What’s going on? Is there a utility ...

Q. I sometimes receive e-mail messages with a “winmail.dat” file attached that I cannot open. Why does this happen, and what can I do to fix it? A. The winmail.dat file usually appears because various ...

.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.

Many times when receiving mail attachments with the new Exchange-enabled Microsoft Entourage v.X from Windows users, you will get a winmail.dat file that is inaccessible under Mac OS X. Alan Sill ...