The inbox-close-to-zero plan has rather revolutionized how I use email, as well. At my last job, my inbox tended to get to a thousand or so regularly, and every so often I would clean out the easier-to-deal-with cruft (usually on a pair of transcontinental flights) and then it would build up again. I spent my last several days at the company sort of heroically beating it back down to zero.

With my new job, my rule is that if the Gmail inbox gets past what I can see on screen at once (about 30 emails), that's a P2 issue, and if it's past a single page (50 emails), that's P1. I've maintained that for 10 months so far.

The important lesson for me was that anything that scrolls off the first page is effectively lost. If they represent to-do items, those items aren't in my list, and they don't show up when I'm figuring out what to do for the day. If they represent things I need to remember, I forget them. Keeping things in the inbox is pointless; the only space that matters is the first few dozen slots in the inbox -- and either I can choose what goes there with aggressive archiving, or I can let randomness choose for me. One of these paths leads to a lot more stress for me than the other.

The other thing that I learned, from digging out of the thousand-odd emails at the end of my past job, is that there's an awful lot of stuff that doesn't actually matter. All those things where I don't have an obligation but I think I might want to follow up later -- nope. If there's an action item, pull it to the to-do list, but otherwise, archive it and work on something important.