Board Game Arena

I had an issue where a player who lost to me in a game messaged me and became aggressive in chat after I refused a rematch. I told him not to be a sore loser, blocked and moved on with my life. Now today I receive a moderation warning because I called the aggressive player a sore loser.

I don't want to receive messages from any players outside of game sessions as there seems to be no reason for messages in this context aside from harassing. Especially if I am not allowed to speak up for myself and just have to silently accept aggressive and harassing messages, I do not want to receive any messages from players I don't know.

It is not pleasant to experience, but the site rules say that if someone sends you aggressive messages, you should report them but not respond. Then they will be moderated and you will not. (and of course block them after doing so)

We do not need to tolerate the behavior, but per the rules we should report it rather than reply.

I did report the player, but my question is about how to turn off the chat messages outside of the game. There is no reason anyone should be messaging me outside of the game and it is quite distressing to be forced by BGA to receive and read such messages.

I don't think you can disable it globally.
But even if it happens once, you shouldn't be spammed by multiple players and then be constraint to report them all.