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Microsoft is trying to dampen criticism by explaining its controversial decision to unify the rendering and editing engines in Outlook 2007 and use only the Word 2007 engine, even though there are some HTML and Cascading Style Sheet attributes that the engine does not currently support.

The move is a significant change from previous versions of Outlook, which actually used two rendering engines: Internet Explorer’s engine was used for reading content, while Word was used for editing content when a user was composing messages.

Outlook 2007 now uses the HTML parsing and rendering engine from Word 2007 to display HTML message bodies.

What is the outlook for Office collaboration? Find out here.

However, there are some HTML and CSS attributes that the Word 2007 rendering engine does not support, and Outlook 2007 now does not use the same standards as Internet Explorer 7.

But SitePoint’s Yank disputes this, saying that he tested the two public beta versions of Outlook 2007 and “knew there was something screwy going on. Many of the newsletters I subscribed to had become unreadable, and SitePoint’s own publications were looking decidedly unhealthy.”

The solution? Use Microsoft’s Outlook 2007 HTML and CSS validator tool, “to tell you which parts of your lean, mean HTML e-mails need to be replaced with old-fashioned HTML sludge. As a second step, you may want to consider giving your Outlook-based readers an easy way to switch to text-only e-mail. Bring on PDF e-mail. I’m ready,” he said.

For Microsoft’s part, the company has provided a list of HTML and CSS standards that are—and are not—supported.

As to why Outlook 2007 does not use the same standards as Internet Explorer 7, Microsoft said, “Customers using Outlook don’t just want to display HTML content the way they do in their browser, but [they] also have an expectation that they should be able to author that content as well.”

Read here about the release of Internet Explorer 7 for Windows XP.

Microsoft’s document goes on to say that “a big thing we heard from customers is that they wanted the richness of the editing experience they were used to from Word integrated throughout Outlook. While Internet Explorer 7 is great, it was never intended to be an editing tool.”

Does Microsoft plan to add support for the missing HTML and CSS standards to Word’s engine? The company’s response was vague: “The Word team is continually examining HTML and CSS support based on customer feedback.”

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