http://bitmsgdy44b7kwtsjbsbvl4r2j7gqpjx6kiqrvbh56phc6pyai5uzmyd.onion/index.php?title=Feature_request_list&printable=yes
Enable per-recipient and per-sender filtering. I suggest keeping a recipient-list (A,B,C,...) and a sender-list (1,2,3,...) and then set the status for each intersection, e.g. A3:whitelisted, A2:blacklisted (with black and white icons).