» 24 ways: Rock Solid HTML Emails
Dave Grenier (of Campaign Monitor fame) provides a great write-up of techniques to make sure your HTML Emails are ‘rock solid’.
Also interesting to note is commercial email marketing campaigns are noted as returning $43.62 for every dollar spent on them in 2009. Compare that with non-catalog direct mail, which returned $15.22 for every dollar spent, and you have some very interesting results.