When I was running my first technology company, I found it hard to sleep: too many thoughts and ideas buzzing in my head. So I used to get out of bed, do email for about an hour, and then go back to bed. On one occasion, I was dismayed to get an instant reply: I wasn't the only one who couldn't sleep.

I realized that I had become an email bully: that employees saw the time stamp and felt, in some way, chastised. That hadn't been my intention but one of the first lessons of leadership is to appreciate that what you mean and what is heard are two separate things.

Everyone I know feels harassed by email which has invaded their waking and sleeping hours. The combination of fear (I don't want to be caught napping) and efficiency (I want to keep the backlog manageable) erodes peace of mind. Executives email all day, much of the night, during meals, during meetings. And everyone agrees: it's awful.

At eBay, management did something about it: they banned weekend emails. If you had to write an email, you could draft it--but not send it. The reform cost nothing. Productivity didn't fall. Innovation didn't cease. People said that it felt as good as a 50 percent pay rise--because it gave them back their weekends.

In the U.K., supermarket CEO Justin King introduced email-free Fridays. You could communicate by phone or face but no emails could go out on a Friday. The goal was to encourage face-to-face communication, build rapport, remind people that they had relationships at work, not just addresses.

Do you dare try it?