you're doing it wrong
Jon Gruber on the reason 99% of email users will not live up to the Official Daring Fireball expectations for appropriate use of electronic mail: "The fundamental source of poor email style is the practice of quoting the entire message you’re replying to." I used to care about things like this. Then I stopped caring...right around the time I stopped caring about whether people sent me email in plain text. Life's been a lot simpler ever since.