If you are doing a bulk e-mail and can use mailmerge then, when you actually
perform the erge, you get the option to set a subject (the same for all the
e-mails) and a recipient address, which word can get from any field in the
database table/view/query you are using as the data source for the merge. So
as long as your data source has the e-mail address, you can do it that way.
If the data source does not have the e-mail address, then you obviously need
some reliable way of looking up the recipient's e-mail address from the data
in the data source (and there are potentially various ways to do that,
depending on what data you have - if you need more ideas on that, let us
know what types of info. you have in your data source).

Alternatively, you might be able to adapt the article by Doug Robbins at

http://word.mvps.org/faqs/mailmerge/MergeWithAttachments.htm

(although it is about merging attachments, it also shows how to send e-mails
programatically from Word)

Peter Jamieson