> We've got quite a few forms on our site that simple subscribe people to
> lists. Often, people aren't smart enough to realize that if they don't
> put in their email address, it won't subscribe them.
Why not fix the forms where the problem is originating from? Trying
to hack Majordomo as a workaround is the wrong approach to the situation.
the back-end that is sending the mail to not send if the email is blank.