In my oppnion, if a player tried to spam a message or repet himself in 2 secs he get 1st warn, then if he respam get 2nd, in the third one he will be muted automaticly for 120 secs=2 mins, and get auto inmuted by the systeme.
And if he send a message then retype it if wouldn't be accepted : */SendClientMessage (playerid, 0x.,"{ff0000}Do {ffffff}[N]ot [R]epeat [Y]ourself");
If the admins were online and a player get muted wrongly the player should Ask the admins to unmute him using /ask [the question]