r-a-y

By default, any member on your BuddyPress site is allowed to send private messages to anyone in your userbase.
This plugin only allows friends and site administrators to send private messages. Thus, acting as another deterrent from illegitimate users.
<h3>Donate!</h3>
I’m a forum moderator on the buddypress.org forums. I spend a lot of my free time helping people – pro bono!
If you downloaded this plugin and like it, please:
<ul>
<li><a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=CT8KZGFEVA3R6" rel="nofollow ugc">Fund my work soundtrack!</a> Music helps me help you! A dollar lets me buy a new tune off Amazon MP3, Amie Street or emusic.com! Or if you’re feeling generous, you can help me buy a whole CD! If you choose to donate, let me know what songs or which CD you want me to listen to! 🙂</li>
<li>Rate this plugin</li>
<li>Spread the gospel of BuddyPress</li>
</ul>

BuddyPress Private Messages for Friends Only

This plugin only allows friends and site administrators to send private messages on your BuddyPress site.

Jonathan Lau

CubePM is a private messaging system for WordPress.
Unlike other PM system, CubePM allows messages to be sent to multiple users and also displays the whole PM system on the frontend using a short-code.

CubePM

CubePM is a private messaging system that integrates right into the frontend of your site.

BuddyPress Private Messages for Friends Only vs CubePM