Was ban mails sent out in error? I don't seem to be banned?

I was sent a rather strange and surprising mail yesterday. It claims I have been banned, yet I have not gotten any warnings in the client, nor do I appear to even be banned(?). I was playing several games after the mail arrived (I had not noticed it since it arrived late in the evening).

For the record, I'm not the flaming or passive-aggressive or otherwise toxic kind of player who writes "gg ez" and the like. I don't consider taunting to be sportsmanlike, especially not when ahead. I rarely write much in chat at all; I usually just mute flaming (or overly taunting) players, or at worst respond with something along the lines of 'Dude, calm down. It's just a game'.

I do have an old NA account which I leveled with the intent to use it to post on NA boards, but I haven't used that one for probably several years. I haven't checked if that one is banned.

I remember getting a warning after a game a long time ago, I don't really remember the reason, but probably I just had a bad game and died too much.

This is the mail I got from Riot: """ [Sender] [email protected] [Topic] Disciplinary Action from League of Legends! Greetings redmattis,

Actions that have been performed on your account are in violation of the League of Legends Terms of Use. You can review these terms at http://www.leagueoflegends.com/legal/termsofuse

Due to the severity of this violation, your League of Legends account has been banned until Mon Feb 22 22:22:22 UTC 2100

If you have any questions, contact our Player Support team at https://support.leagueoflegends.com/home

Riot Games Player Support """