Personally I think it's a bit presumptuous of you to think that all your staff want to send emails with "Kind regards".
True enough, there are one or two odd ball solicitors here who deal with litigious matters and as such feel no empathy towards some of their contacts. There's a separate rule in place for them.
The wording's not my decision, I just roll it out to people.
To paraphrase IT's normal ambivalence to their users: "So?"
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.