When you say very similar, is it in style tags or inline in style attributes on the tag? As far as I'm aware, GMail and Outlook.com both strip <style> tags from the display, but work quite happily if you inline the CSS in a style attribute.
Ah... that's one to try out this afternoon. :)
And that it why IT is held in such derision by their users.
Nah, we love you all, really. Every single one of you.