E-mail Priorities

How fast should we respond to email?
Amit Asaravala writes on managing e-mail. He proposes that high priority means today, low means that no answer is needed and normal means within a week. He also says to pick up the phone if something is more urgent than “today”. Sounds good to me. I also use different communication mechanisms depending on urgency and type of information needed:
Monday 05 June 2006 11:39