IDLE ensures that the server will inform the client of new messages even when there is no other activity taking place between client and server by ensuring that the connection is not disrupted by a timeout. Because of this, IDLE is often cited as providing a user experience similar to that of Push e-mail.
IDLE's ability to maintain a continuous connection ensures that clients receive updates even when there is no ongoing communication between them and the server, making it comparable to the real-time notification experience of push email.