If you’d like an ultra-quick summary, here goes:
- Just avoid positioning with CSS in HTML Email. It probably won’t work.
- Lots of email applications chop off the <HEAD> and <BODY> areas of your HTML email. So don’t put your CSS there. Put it under the BODY tag, with your content. It’ll still work there.
- Don’t link to external style sheets. You’ve got to use embedded or inline CSS