Dennis Kennedy has some more thoughts about email management in Email Management - Eating My Own Dog Food.
He talks about what you do when you get beyond the "empty your inbox" idea. There are still all those articles you need to handle (those "do later" items). Dennis uses Outlook 2003's follow-up flags, but he has discovered that when he gets too many follow-ups, e-mail paralysis sets in again. This is where he (and I) moves away from email management to basic priority management. Operate intentionally: how frequently do I want to read and respond to email today? How much time do I have to devote to those thoughtful responses? And then stick to my plan!
And the tools I use need to support the way I want to operate. Dennis pines for "touch it once" systems, rather than "handle it later" systems.