Couldn't find the exact thread, but this article was referenced in it and I think sums it up pretty well.
code-html-email-newsletters
I understand that this is a Dreamweaver CS4 issue mostly - as it no longer allows disabling CSS styles. From what I understand in the article, best practice includes tables and inline CSS styles, although Outlook may not react well.
I keep a copy of CS3 on hand to create the emails and use old-fashioned HTML