When I was younger and more foolish, I'd occasionally make late night phone calls that I'd later regret. I've got something of an artist's temperament and it's best to just admit it happened. If I'd been in the habit of executing such communication faux pas (plural?) via email, I could take refuge in a new feature of GMail Labs.
Mail Goggles allows you to set up a test for yourself should you be concerned that you might later be under the influence and thus unable to make good decisions about the emails you might send. Mail Goggles assumes that whatever substance or stresses you find yourself incapacitated by will also rob you of your ability to do 8th grade math. They may be right. Look for it under the labs button in GMail.
qv: Official GMail Blog