|[Email Sanity: How to Clear Your Inbox When You’re Drowning||Zen Habits]1|
A good article about the Zero Inbox approach, how to get there and how to stay there.
One has to decide on the use of e-mail: alerts, communication, reference information, etc. The author effectively suggests limiting things to directed communication and (apparently) use other systems for the other communications form. Zero Inbox can work even if you want to keep your reference information – you do have to get it out of your inbox (and put it somewhere else).