Actually, it's not really blocked (Score 1)

I still receive html e-mail from outside sources. The default view (and preview pane) have been changed to plain text - you right click on the banner telling you that and convert it back to html - poof, an html message again. I can't compose html though, only rich text, and if the recipient id a DoD person they'll have to go through the same rigmarole to see my original formatting.