CSS-Tricks #30: Creating and Sending HTML Email
Designing HTML Email is far cry from regular web design. Sure, they both us HTML elements, but the whole philosophy is different. In this world, you gotta do all you can do to make sure this single design is as viewable as absoulely possible in all email clients, and there are a heck of a lot more email clients than their are browsers. HTML Emails are all about table based layouts, inline styling, and direct URL's. Codin' like it's 1999.