I especially like his theory of Darwinian email importance:
> The importance of an email isn’t something you need to spend time thinking about. If it doesn’t immediately and obviously make you feel you should reply to it within the next day or two, it’s not that important to you. Archive or delete it.
> If it’s sufficiently important to someone else, that person will expend effort to make it come back to you. If the email does not come back to you, you would have wasted your time replying to it. Win-win.