This add-on allows your members to create and maintain multiple contact lists that can be used when creating a new conversation or thread.
Contact lists can be useful for admins to start a personal conversation with all their moderators at once, or all their sponsors, etc. It's also useful for normal members that want to maintain contact lists for friends, or for members they consistently role play with, or to contact all staff, etc.
You can demo this add-on here: demo and test...
