IMAP IDLE

IDLE is an Internet Messaging Access Protocol (IMAP) extension. It allows an IMAP client to tell the IMAP server that it’s ready to accept real-time notifications and new messages. IMAP IDLE enables an email client to tell a receiving mail server it’s ready to receive an email, meaning that subscribers don’t have to hit a refresh button to “pull” new emails into their inboxes. Instead, they’ll automatically see new messages when delivered.