Most people would be quite happy with Plain Text (and those of you who send emails with purple backgrounds shouldn’t be allowed to use a computer anyway).
Ouch! Of course, he’s right. Not only do the stupid backgrounds and flashing images take up more space, but they make your email, the words you are writing, the actual idea, the message, the whole purpose of typing, much harder to read! Duh! How dumb is that?
Save the designs for a webpage, and even then be careful not to go overboard on it! (Obviously, from a look at mine and Scoble’s weblogs you can see we don’t care much about the design looking pretty. *L* Just clean and readable!)