These are network data packets that go between you and server. It has nothing to do with chat messages or email messages. It is designed to catch people who use macros or bots to rapidly press key sequences. Sometimes it will catch innocent players if they are bashing away at keys, perhaps in frustration, and it is being done rapidly enough to appear robotic/automated. The other possibility is network lag. You press 10 keys in 10 seconds, there is some kind of network issue between your ISP and ZOS, and things get backed up. Eventually it clears out and suddenly ZOS gets all 10 key presses at once and decides you are hitting keys too fast to be a human and are a bot or a macro.

When I got back i was still in the dungeon group, it had happened to 3 out of 4 of us. So prolly not on my end.