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 ...

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

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 ...

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.

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.

If you regularly receive winmail.dat files from business associates, Letter Opener is well worth the investment.