Take The Email Etiquette Pledge
I love the quote: "If a emale is writon with speeling mestakes and gramitckal errors, you mite git the meening, however, the messige is not as affective, or smoothly redable.
Poor writing is equivalent to someone speaking with spinach stuck between their teeth. Listeners and readers concentrate on the spinach; not what is being said."
http://www.netmanners.com/email-etiquette/courtesy-3/