[NSFW] EMail plugin

I am looking for an email plugin which works with S2Member. What we want is the ability for members to email other members (a group) and those members get the email in their inbox, not a notification. Members could them respond to the email and the response would go to either the group or to the sender.
Does this plugin do that, and if not, is there a way to accomplish what I am looking for?
Susan Neves

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