Returning a Phone Call
Aim to: Return a business call the same day. "Anything past 24 hours is too late for most people in business," Bremer says. Downing recommends that you return personal calls within two days.
If you are late: Apologize with a simple "I'm sorry." Avoid explanations unless you have a very good excuse.
Tip: If you don't have time for a long conversation with a friend who has left a message, send an e-mail saying when you will call back.
Returning an E-mailAim to: Respond to business e-mails within 48 hours. (Any later than that is bad for your image at work.) Try to show friends the same courtesy. Make sure to use the automatic out-of-office reply when you're away.
If you are late: "If you know you can't respond in a timely fashion, at least send an e-mail to say you're in a time crunch and will get back to the person as soon as you can," Bremer suggests.
Tip: Complex instructions―or anything that might trigger a lot of back-and-forth messages―may be better dealt with over the phone.