pdf convert to winmail.dat

I send a attach with .pdf and the reciever is saying they can't open it (and they do have Acrobat Reader) and they telling me that a dat file (it says winmail.dat).
how can I convert to that??
thanks

Turn off Rich Text Format in your email programs settings, then send it.

Zipping the file will probably work.

------------------
Black holes are where God divided by zero.

This is an RTF problem for Outlook senders sending to non outlook users. Turning it off should work.

Are you on an NT Network?

thanks /// that was perfect