From 43 Folders:

“This post is part of the Inbox Zero series. You’ve doubtless already discovered your inbox won’t stay at zero — and it shouldn’t. As I said yesterday, this is a process, not some miraculous one-time event like a tonsillectomy or a Jandek concert. And you can’t just wave a magic wand every couple weeks and make it all go away. Why not use the august occasion of your newly empty inbox as the chance to start mending your ways going forward?”

I can tell you from personal experience it feels pretty darn good to have an empty Inbox, but it takes constant work. It IS worth the effort though! Here is the link.