IIRC I have seen this discussed here on HN, someone had A/B tested their automated thanks-for-signing-up response mails "from the CEO" and found a significant improvemed response rate when they included one small speling mistake in the Subject.
pretty sure that mailing list email body copy with the slightly awkward formatting a CEO might use for general correspondence will tend to outperform a neat obviously-a-mailshot-created-by-marketing HTML template when it comes to generating many types of response as well.
