You'll need to do it the way that is frequently described here and is based
on starting in Outlook, not Word.:

Close Word, open Outlook
Go to the Public Folder and select the Contacts (select the specific
Contacts to merge with)
tool | Malimerge | merge to email | type a subject | OK
Word starts itself up now.
Use the Insert Merge Fields button to get to Outlook's Contacts Fields. (NOT
insert word fields button)

Merge to email | OK.

Regards

Judy Gleeson
MVP Outlook
Trainer and Consultant

There are various articles about using Outlook here: www.judygleeson.com
Canberra, Australia