+1 Some people are really annoying but at the same time you don't want to disable all messages in case somebody talks to you, or a moderator/admin is calling ya.
There could be a button on the Connections List to mute/unmute players.
I already know about that, I use them on these random servers, but at the same time some servers don't allow players to block messages (If the server has an InSim they would put a message on screen to re-enable messages, or they would kick you or ban you if you keep on blocking messages), plus if I block messages a moderator/admin could be talking to me and I wouldn't notice and would end up banned thinking Im ignoring him.
Sounds simple enough, but you seem to forget that some servers don't allow you to block messages (and actually kick you if you do it), so this would be quite useful. I, for one, would like to see this implemented.