
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