Merge to Fax not available

[Rocky B]

the Merge to Fax button is greyed out on the toolbar, even
though I have Fax Service installed in WinXP and set up as
a email service in Outlook XP. I used to be able to put a
fax number field in the source document and "mass fax"
individual letters using Office 97 and MS Fax when I had
Windows 95. Has anyone figured out how to get this to work
using Win XP and Office XP??? Many thanks

Rock