Johnny Holland discusses in some considerable detail how it might be possible to add game-like behaviours to email to help people be more effective and achieve Inbox Zero more easily. It's a very interesting post and I'd love someone to go ahead and build an email client that takes these ideas on board. I think it would be fascinating to see how we might remake our relationship to one of the most pervasive communications medium of the modern world.
But Holland doesn't even mention the most important problem: That we send far too much unnecessary email for reasons which are emotional rather than logical. Encouraging people to process their email more effectively is only half the battle. We need to remove as much content as possible from the email system, especially newsletters, notices, FYIs and other forms of occupational spam. We need to empower people not to cover their ass, not to CC their entire department, and not to get sucked into endless and pointless - but very polite - conversations by email.
Until we learn to send less email, learning how to process it is only going to give us a false sense of success and may even encourage us to, well, send more email.