Hi,
When a user blocks another user with the Youzer plugin block extension, the blocked user could still send messages to the user that blocked them.
I informed Youzer developer about the issue and they said this might be because you are not using the same hook as buddypress hook.
It would be nice if block feature is integrated with Bp Better Messages. At the moment, there is no way a user can block someone from sending them messages.
Regards,
Ace