This is an annoying issue. I have my email alert tone set to calypso. However I'd guess 75% of the time I get the default "Ding" sound. The other 25% I get the calypso tone. I'm using the stock email app with 3 different address and they all seem hit or miss. Any ideas? I've tried turning it back to default and back and have reset the phone (4S) holding power + home.