While it isn’t officially released until June 15, we thought now might be a good time to prepare everyone for what they might expect when Outlook 2010 hits the shelves. It’s been quite the ride since we learned the latest version of Outlook, just like its predecessor, would be using Word to render HTML emails.

Microsoft said they were listening, but like most of us feared it was just too late in their development cycle for a change this significant to be made. Here’s what Dev from the Outlook team had to say:

“At this point, our plans for email authoring and rendering in Outlook 2010 are unchanged. However, I can tell you that this is a significant topic of discussion as we plan our business going forward, and something we will definitely be thinking about for future releases of Outlook.”

This is definitely a good thing. While future versions of Outlook will likely have far superior web standards support, where does that leave email designers today?

Accepting that the damage is done

According to email client stats Microsoft Outlook just over 35% share of the email client market, with Outlook 2007 taking up a quarter of this. Outlook is far and away the most popular email client on the market today. Further to this, Outlook 2007 usage grew 2.8% in 2009, while older versions of Outlook dropped 5.5%.

This shows a significant number of Outlook users have upgraded, and will likely continue this trend following the release of 2010. The Word rendering engine isn’t going anywhere.

Looking on the bright side

While this isn’t glowing news to report, our recent testing combined with the research others are doing indicates that the Outlook 2010 renderer is actually exactly the same as the one in Outlook 2007. This means you won’t need to make any significant changes to your current email templates or learn any new tricks of the trade.

I also wanted to announce the availability of Outlook 2010 support in our design and spam testing feature.

While the additional of this email client isn’t useful for diagnosing design issues, you now have the results to show clients and colleagues that you’ve got every email client covered.

Providing a fallback, but not relying on it

Below is how to trigger an alert in Outlook 2010 encouraging the recipient to open the email in a browser if it’s displaying poorly. Here’s what the alert looks like.

It appears that if a span tag appears in your email body, or a CSS declaration involving a span appears in your stylesheet, Outlook will always display this message. Of course, the browser will do a much better job at rendering your email, but it’s not something we’d ever recommend relying on.

Even when a subscriber clicks this alert, they first see a security warning and then the email is opened in Internet Explorer, even if that isn’t the subscriber’s default web browser. Far from a pleasant experience.

Our advice

In light of this news, what should email designers be doing differently? To be honest, nothing. Do what you’ve always done: Keep your email simple, use tables for layout and inline your CSS.