emails should be five sentences long or less. I completely agree. I have a co-worker who really needs to read that article, his emails can turn into miniseries. My favorite is when he asks me to tweet something for him. I have to really put my editing hard hat on and get to work! It's all in good fun, we love him despite his lengthy shortcoming.
The article reminded me of one of my biggest email pet peeves (OK, I have a lot of them but this one is up there). My big peeve is when people need you to do something and they forward you an email with just the message "see below" written. You scroll down and it's 2 days worth of back and forth conversations. You then not only need to read a load of useless crap, you also need to figure out what it is you need to do. My brain goes ugh.
Summarize! It takes 30 seconds and you'll get a much faster response. Trust me.