E-mail is addictive, it has been shown, in the same way that slot machines are addictive. You press the send/receive button just as a gambler pulls down a slot machine lever, because you know that yo will receive a reward (mail/a payout) some of the time. The best way to increase the chance of a reward is to press "Send" a lot. In one study, participants manually checked their e-mail thirty to forty times an hour.
Working at the speed of e-mail is like trying to gain a topographic understanding of our daily landscape from a speeding train--and the consequences for us as workers are profound. Interrupted every thirty seconds or so, our attention spans are fractured into a thousand tiny fragments. The mind is denied the experience of deep flow, when creative ideas flourish and complicated thinking occurs. We become task-oriented, tetchy, terrible at listening as we try to keep up with the computer. The e-mail inbox turns our mental to-do list into a palimpsest--there's always something new and even more urgent reasing what we originally thought was the day's priority.