peexa provide the best features of messaging plugin for wordpress by using Private Messaging,It is created by viewing security .UN authorized user can’t access your messages.
It hide many conversation that u want to hide , private messaging is easily done by using this plugin that is suitable for wordpress., you can see your every message easily . interface is to much easy and friendly. Private Messaging powered site to another level by letting people interact with each other, awesome new message notifications and easily initiate chats and reply to messages
Demo of private messaging is here:
Downlaod free Privat Messaging from Here: