You don't specify what version of Word you're using, but the most like
reason is explained in the following excerpt from Word 2003 Help re emailing
a doc as attachment:
To use this procedure, you must be using Microsoft Outlook, Microsoft
Outlook Express, Microsoft Exchange, or any 32-bit e-mail program that is
compatible with the Messaging Application Programming Interface (MAPI)
(MAPI: The Microsoft interface specification that allows different messaging
and workgroup applications (including e-mail, voice mail, and fax) to work
through a single client.). In addition, you must set up an e-mail account in
your e-mail profile.
IOW, just adding the button to your toolbar isn't enough.
HTH |:>)
Bob Jones
[MVP] Office:Mac