I use mate all the time, probably far too much to be honest but not if I'm talking to someone like my manager or director other than that you're fair game.
I used to know a guy that would literally blow his top if someone he didn't know called him mate, much amusement for the rest of us.
I used to know a guy that would literally blow his top if someone he didn't know called him mate, much amusement for the rest of us.