Keeping your email under control requires an unreasonable amount of discipline. I've managed to avoid 'defaulting' on my email so far, but at a decent overhead

Keeping your email under control requires an unreasonable amount of discipline. I've managed to avoid 'defaulting' on my email so far, but at a decent overhead rate: Every hour or two, I wipe out my inbox completely and leave only items that absolutely require an action. Most mail is read once and interesting email gets archived by sender name. I have lots of filters set up for people who usually send me uninteresting mail. Everything else is deleted. I've almost lost control a few times - mostly because of vacations- and I'm certain that I'll hit a tipping point where my time doesn't scale to my inbox size. I couldn't handle my boss' email load, for instance... Are there any good techniques that scale for dealing with email?