I suspect IMAP IDLE is essentially identical to iOS push notifications. You connect, get a list of messages since the last time you were disconnected, then swi

I suspect IMAP IDLE is essentially identical to iOS push notifications. You connect, get a list of messages since the last time you were disconnected, then switch to an idle state where new notifications come in real time. If the tcp session is severed, you have to reconnect, rinse and repeat with both IMAP IDLE and iOS push notifications. I'm partly guessing here, but I'm not sure how it could work any other way.