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 ...

Getting a DAT file open on your Windows machine can require one of a few different approaches — to be determined by the kind of data the DAT file contains.

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?