It’s not nice for Mac users to laugh at those who are less fortunate, but when the situation involves a intoxicating mix of Microsoft, email marketers and HTML email, the temptation becomes irresistible.

Outlook 2007 is making a change in the way that it renders HTML email. In the past it used the rendering engine in Internet Explorer, but now it is switching to the less fully-featured rendering engine in Word 2007.

According to Campaign Monitor, this is a disastrous step which “takes email design back 5 years”.

In particular, Outlook 2007 users will find the following things missing from their HTML emails:

1. No background images – Background images in divs and table cells are gone….
2. 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.
3. No support for float or position – Completely breaking any CSS based layouts right from the word go. Tables only.
4. Shocking box model support – Very poor support for padding and margin, and you thought IE5 was bad!

Campaign Monitor carries an image of how the same email laid out with CSS looks in Outlook 2000 and 2007:

Email marketers are steaming with rage . They will have to redesign all their HTML marketing templates as Office 2007 starts to spread through the corporate and home user markets.

In an interesting twist, some takes this as a tacit admission by Microsoft that the HTML engine in Internet Explorer 7 is still a security liability.

The most important thing Mail.app users can do about this is to keep themselves clean by resisting the Schadenfreude tsunami.