Microsoft Outlook 2007, released next month, will stop using Internet Explorer to render HTML emails and instead use the crippled Microsoft Word rendering engine. Outlook enjoys a 75-80% share of the corporate email market, which is similar to Internet Explorer's share of the browser market - they make the rules.

E-Mail Marketing company Campaign Monitor has been doing some early testing, as have a few other brave souls, and come February, here's just a taste of what won't be supported:

- No background images - Background images in divs and table cells are gone, meaning Mark's image replacement technique is out the window.

- Poor background color support - Give a div or table cell a background color, add some text to it and the background color displays fine. Nest another table or div inside though and the background color vanishes.

- No support for float or position - Completely breaking any CSS based layouts right from the word go. Tables only.

- Shocking box model support - Very poor support for padding and margin, and you thought IE5 was bad!

Microsoft have released a full run down of what is and isn't supported, including a downloadable validator that helps you validate your HTML for their engine. Word of warning though, it only works with Microsoft software and Dreamweaver.

Get the full story at Campaign Monitor

Related Link: Word 2007 HTML and CSS Rendering Capabilities in Outlook 2007