If somebody sent you email with attachment using the old MS Outlook 97 or 2000, the attachment might probably appear in your email client as a winmail.dat file.
You can use the free Winmail Opener utility to extract the email attachment from this winmail.dat file.
The process is pretty simple. Just drag-and-drop the winmail.dat file into Winmail Opener's window, its content will be shown. Alternatively, you can also click the "Open file..." link in Winmail Opener and select the winmail.dat file.
Then, just drag-and-drop the attachment from Winmail Opener to your Desktop.
Click here to download and install the free Winmail Opener utility. It is freeware for both commercial and personal use.