Are you a die hard Email fanatic? Need to know the instant a message comes in? Maybe you don't want mail checking in the background, since you might be on dial-up. Whatever your needs, here is how to change it. Open 'Mail' Next, choose 'Preferences' Mail -> Preferences -> General Now choose the mail interval that is appropriate for you - 1, 5, 15, 30, 60 minute intervals - or only manually, when you click the 'Get Mail' button. To make this work, Mail has to be running in the background. What I generally do is, open Mail, and then press 'Command+H' which will hide Mail, and you can just look at the Mail icon on the dock for new mail notifications.