Block Messages From not in list (Not in contact list)

Hi
I want to block my server Users From Sending message To a contact , that is not in Their Contact List
For example , i add a new Contact to my contact list (by a None Account , not admin Account)
The added Contact , Deny my Add Request , But i still Have his Contact in my contact List , and i can Send Message to him By any Client , And the Problem , Is , That Contact who Deny my Add Request , Recive my Message !!!

How can i Block it ?
There is any Module to block it From server Side ?
Please help me