I have found few routines that bring more peace than Inbox Zero.
For this I am indebted to Merlin Mann and David Allen.
So, what is it all about? An empty inbox. To reach it, you need very things: namely an inbox and will power.
Apply the following routine on your mailbox:
1. Open a mail
2. Scan it
3. Decide what to do with it (trash it, do it, archive it, schedule time in your agenda to do it, park the action to accomplish on your appropriate context list)
4. Back to 1
One caveat: never put back a mail in your inbox.
Happy inbox cleaning