Move Public Subscribers to Registered Subscribers

I am using a plug in (BNFW) to send out an email whenever an old post is updated. I have 270 “Public” subscribers in Subscribe2, but only 4 are “Registered. Those are the same four original Admins/Authors that started the sight, and they are the only 4 that are getting the update email. Is there a way to move the Public subscribers into the Registered subscribers to see if everyone will get the update email. The Public subscribers do get the initial email when a new post is added.

The page I need help with: [log in to see the link]