Privacy plugin that makes it more difficult for admins to read PMs

[cpradio]

I good start would be forking and modifying this plugin

Kinder Guardian - let New members message Staff

Without this plugin, New members can only contact Staff by email or by replying to their Welcome message This plugin allows them to message Staff from either the Staff members User Card, or the Staff members Profile page. It does not let them send messages to non-Staff members. display the Flag icon or it’s option to send a message from its modal. let them send messages from their own Profile page. let them send messages if the site has them disabled