Though DAT files, which house data as the shortened name implies, are usually best left alone, here's how you can open them.

If you're having trouble opening a DAT file, I'll show you a simple and free way to do it. This method works on both Mac and PC. Just open your browser and go to winmaildat.com. It's a ...

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.

Another approach is to download a program that can translate the winmail.dat file. Several developers have created helpful programs that can open the files.

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 ...

If your e-mail program does not support this particular blend of RTF, you’ll end up with that danged .dat attachment–and no easy way to open it. You have a couple of options.

If the DAT file you're trying to open is text, you can convert the file into text in the Microsoft Excel program by first saving it as a CSV file.