A friend asked me about a weird e-mail attachment he constantly receives from one his friends. "The file's unreadable," he said, "I can't find a program that can view, decode, or convert the thing." He said the file's always the same -- winmail.dat.
Who's Dat?
My friend isusing Eudora, an ancient e-mail tool and is receiving e-mail from someone using Outlook.
Quick aside: Don't even consider switching to Eudora; it's no longer being sold or even upgraded. There's a new version in the works, but don't hold your breath. More about that in another blog.
The winmail.dat file is generated from Outlook (or Microsoft Exchange) and it's loaded with Rich Text Format (RTF) formatting code -- italics, bold, and font info. So the file appears as an attachment, but it is useless to my buddy.
The Fix is In
If you're in the same boat -- or the Outlook user -- it's easy enough to turn off the option to send Rich Text Formatted e-mail messages. In Outlook 2003, choose Tools, Options, select the Mail Format tab, Internet Format, and from the pull-down, choose "Convert to Plain Text Format". Click OK, OK to save the change.

Get rid of Winmail.dat files
It may also make sense to stop using Word as the e-mail editor. Do that from Tools, Options, Mail Format tab, and de-select "Use Microsoft Office Word 2003 to edit e-mail messages."
Have an Outlook tip -- or hassle? Send it to me at inbox.