7 rules for communicating clearly and concisely in emails

There's a good article here about efficient emailing.  In particular, I agree completely with the idea that any email should only require one specific response or action from the recipient.  If you ask for three things, there is a fair chance that you won't get a response until all three things have been done.  If you ask for one thing, you'll probably get a response a lot quicker.  If you need three things, send three emails.  That way the easy responses can be made straight away.