http://bitmsgdyvsmwgsimkxplisxbzpewvkhfm3fmomzd63apaymaxiznz6ad.onion/index.php?title=Feature_request_list
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). Then allow setting the "mood" for each recipient by coloring them in red, yellow, or green (compare suggestion above).