Email, Messaging, & Video Calls Email Instant Email Updates with IMAP IDLE in Mac OS X Mail by Heinz Tschabitscher Writer A former freelance contributor who has reviewed hundreds of email programs and services since 1997. our editorial process Heinz Tschabitscher Updated on April 08, 2018 Email Yahoo! Mail Gmail Tweet Share Email With IMAP accounts, Mac OS X Mail can use the IDLE command (provided the account supports it). Instead of polling the server for new mail periodically, Mac OS X Mail just waits for incoming messages—which are sent automatically and pop up just about instantly. Get Instant Email Updates with IMAP IDLE in Mac OS X Mail To have emails appear instantly in IMAP accounts in Mac OS X Mail: Select Mail | Preferences... from the menu.Choose Accounts.Select the desired IMAP account.Go to the Advanced tab.Make sure Use IDLE command if the server supports it is checked.You can additionally uncheck Include when automatically checking for new mail. Keep in mind that Mac OS X Mail receives instant updates only for the open folder, though.Close the preferences window. In Mac OS X Mail 2, you can use the IMAP IDLE add-on.