advice on indexing email

I am currently writing a light-weight mailing list manager which
interfaces directly with my postgresql database for user authentication.
Also, I would like to somehow create a full word index (like fti in
contribs, but only one entry for each word instead of for each character)
of each authenticated email for performing queries on the contents of
emails. The actual email would then be stored in a seperate directory.
Lastly, an entry would be stored in the postgresql database holding the
pathname to the email and some other miscellaneous information, such as
date, email and subject.

My problem is how to create the full word index. The actual code to
seperate the email into seperate words isn't a problem, but should I be
using INSERT, BEGIN/END or COPY? In this last case, I would have to create
a temporary file holding each word of the email and then use COPY... all
of which also has it's fair share of overhead.

Any advice on the subject would be much appreciated,
Marc Tardif