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 ...

When you send an email message from a Microsoft Outlook client that is configured incorrectly, the receiver may receive an attachment with the name winmail.dat. This is a binary attachment that ...

Letter Opener converts winmail.dat attachments on the fly, so you can actually see and use the attachments the sender intended you to have. [Editor’s note: The following review is part of Macworld’s ...

If you've ever received a forward from an Outlook user in Mail.app containing an attached winmail.dat file, you probably scratched your head wondering why this strange file ended up in your inbox and ...