GPL Download – Private Messages for UserPro is a WordPress Plugin being distributed by Codecanyon. This plugin adds private messaging between users and allows users to receive notifications about new messages, view conversations, reply to other users.

Private Messages for UserPro Features :

Allow Users to Send and Receive Private Messages
  Sends notifications to users when they receive a message
  Trigger messages from any custom link !
   Ability to broadcast a message to all users.A success / failure notification is sent after the broadcast is completed.
  Administrators can restrict broadcasting by selecting which user roles have permission to broadcast
  You can add a Note that gets added to the footer of all private messages.You can use this to set up disclaimers or any other important notes. For example, “XYZ website is not responsible for all messages sent via this website by any user.”
  Users can block/unblock other users from messaging