Mmm I see it should be vertically aligned with the first line text OR subject if we have a subject (which might be the same anyway). I don't think we can do this with the current way of puting the character counter (as a generated content of the button) so I think we'll need to change completely how it works. Let's do this in another bug focussing on this only, as there will be javascript change. Can you please file a bug for the counter only ?