@jordanerollin There is a group e-mail plugin called “BuddyPress Group Email”. I have never used it therefore have no working knowledge of it.
I can see from the website there is a tab it says “Send Mail”, but you could possibly change that via a language file edit if you wanted it to say “Messages.”
From the quick read it says:
Allow group admins and moderators to send emails
The plugin itself has been around for a good while. I found it in a post from 5 years ago, so maybe somebody with some knowledge of the plugin could better advise.
https://buddypress.org/support/topic/groups-send-internal-message-to-all-group-members/
Note: It is not free.
