Is very difficult to allow private messages to only your favorites?

Question

I do not want to remove the private messages.

But a spammer should not be able to send messages to everyone.

Comments

I found a temporary solution (for activated moderation):
http://www.question2answer.org/qa/29414/certain-amount-of-points-before-private-messaging
File: qa-include/pages/message.php  (in 1.7).
If you are facing the same problem, enable moderation and add code of Sama55.

Answer 1

I think the only way currently would be to add some custom code to qa-include/pages/message.php around line 127 that checks if the person sending the message is favourited by the user they're sending to.

One alternative would be to override the qa_send_notification function using an override plugin and not send the email if they're not favourited, or if the sender has too few points.