Be able to block messaging from a country

I just played a game recently where this player is constantly harassing me for supporting my alliance in attack him what is worse is that he is also playing in another game I am and also harassing me there as well.

I am fed up with him and his toxic behaviour but he is filling my message box with his toxic messages when my allies don't message me so I check my message box unnecessarily which have started to bring me down.

Being able to block such toxicity during games would be great as I would not have to deal with someone harassing me for playing a game.