Help me how to turn on email ringtone alert!

[mptu]

I'm using Softbank iPhone 3G (Japan). Tell me how to turn on the email ringtone like sms ringtone? I'm just hearing it when I'm using head phone, if not, it's only show a message alert on the screen, no vibra, no tone??? Why???

[heath_rox]

this may sound stupid but try restarting the phone
also try playing your ringtone form settings