Hello, I just received my New iMac 2013. I have to master ML now!!! I can't figure out why Mail emits such a faint, I mean very faint, new email notification sound. System wide, the sound level is quite high but whatever notification sound I chose which by the way plays accordingly to the volume set-up of the System, Mail reverts to its original sound. This is the one that is almost inaudible. So much actually that I have to check by myself if I have new emails or be notified by Notification centre. Does someone has the same problem or is it a bug in Mail? All works so flawlessly in my new iMac. Only this little quirk. Thanks for sharing thoughts. R.