A few days back, a business contact e-mailed me a copy of a presentation as a .PDF file. No problems there, except that when it got to me (using the Mozilla Thunderbird e-mail client), it was called winmail.dat. I tried saving the file as a .PDF but Acrobat Reader didn’t like it so I had to do some googling to find out what to do with this strange file (I remember having problems with this during a migration from Pegasus mail to Microsoft Exchange and Outlook a few years back and we had to resort to using plain text e-mails until everyone had been migrated).
I found an article on the PC Hell website that not only explained the purpose of the winmail.dat file (used by Outlook Rich Text e-mails to carry the formatting information in transport-neutral encapsulation format), but also gave links to various programs that can process the winmail.dat file. One of these is Steve Beadle’s WMDecode utility, which successfully extracted my .PDF from the winmail.dat file.