In the real world, when the rules are broken, people are punished for it. The bot could include an img tag to goatse for repeat offenders. But since corporate culture actively discourages trimming unecessary quotes (I've actually caught crap for trimming at work), we don't really have rules. Hell, the worst offenders for bad mail at my company are the high mucketies themselves. With their example, it's hopeless.
And then there is the other extreme like my father who deletes the entire email and then replies. OK, Dad. It's nice you said, "Snickerdoodles", but what was the question?