I sometimes send messages to teammates who had to carry our team just giving them props or thanks. I'll send a message to enemy players if I got a bullshit kill on them like when I sniped a sniper trying to kill me and I had Last Word. Not trying to stir up trouble I'll just let them know it's ridiculous that I had killed them. If I traded out with another sniper I'll shoot them a "lol" message. No hate mail because that's lame.