I guess I don’t have enough business friends, or at least, my work colleagues as a rule still put too much distance between themselves and their emails to make that a sensible rule of thumb. But, in other contexts, perhaps you’re right.

This extends to using email as emergency communication for urgent requests. If you need a response right away, the phone (or getting up and walking down the corridor) is the answer, not email. Don’t forget there are people who (unbelievably) only answer their emails once or twice a day.

I disagree. In the business world your recipient will have a blackberry to answer you immediately, even when in a meeting where taking a call would be inappropriate. Immediate response to email is the new expectation. . . . . the new minimum standard. Phone calls go to voice mail. Listening to voice mail is tedious, sequential and time consuming. Voice is a useful, but secondary, means of communication in case of emergency. Email is primary.