Ask designers which mail program is the bane of their existence, and you'll find that Outlook tops the list. The reason why the most popular email reader is also the most painful is simple: it uses Word to render HTML emails — and Word does a very poor rendering job.
Continuing a decision made in 2007 to render HTML with Word in Outlook, Microsoft confirmed that Outlook 2010 will also use Word. In response to this decision, the fixoutlook.org campaign was created in an attempt to change Microsoft's mind.
Microsoft responded to the campaign with a blog post that sadly misses the point of the campaign. Instead of responding to the concerns of the Twitter folk, the post goes to lengths to explain the benefits of composing in Word.
As one poor sap that has had to create HTML email in the past, Outlook's treatment of HTML is a weight tied to the ankle of any designer or developer that steps into email. Lovers and overusers of divs and CSS need not apply as you will be returned to a world of tables and font tags that one previously tried to escape.
The Redmond giant correctly points out that an email marketing firm had set-up this campaign and that the Email Standards Project is not an industry body; however, the campaign has tapped into the latent issues surrounding Outlook and as Microsoft continues to hide behind the "Outlook plays well with Outlook" mantra, it will not win any friends.
Rather than move the state-of-the-art forward, Microsoft has decided to continue applying the handbrake and hopes you enjoy the stationary experience.