Limit check-ins: The worst thing a morning person can do is give away his most productive 30 to 60 minutes of the day by checking and responding to e-mails the first thing in the morning. Set two or three e-mail check-ins around natural breaks in your work routine.
Control question time: Most e-mails don’t require an instant answer. You’ll waste less time and have more reasoned responses if you drag correspondence to an answer file and write replies all at once.
Block reply all: Needless replies waste your time and others. Encourage others to only copy you if a response is required.
Shut off before you turn in: Not only will last-minute bad news or things requiring a response keep you tossing, but concentration and the light from a computer screen before bedtime can affect the sleep cycle and make you less effective the next day.
Don’t respond on off hours: Letting people know they can disturb you on evenings and weekends will only encourage them.
Let others know your limits: People will understand if you tell them not to expect you’ll answer the phone or reply to a message in real time. If an organization has evolved expectations of immediate response, discuss it in a meeting because the demands are destined to get worse and become counterproductive.
Source: David Posen, author of Is Work Killing You?