The impact on email marketers
If you haven’t caught word already, then allow us to be the bearer of less-than-good news: Outlook 2007 can cause (minor, but curable) headaches for email marketers.
Previous versions of Outlook used the Internet Explorer engine to render HTML emails. This allowed designers to employ sophisticated, CSS-based designs with predictable results: if the message looked fine in IE, then it would look fine in Outlook.
Instead of using the IE-based HTML rendering engine, Outlook 2007 will use the MS Word HTML rendering engine. Considering the inherent HTML rendering limitations of MS Word, this basically signals the end to many of the tricks that email designers rely on to create professional, appealing email designs.