See my post here - Is Gmail updated for Tour?
I was told the only way to remedy this problem is to shut off HTML email. As soon as you get one of the "huge text" emails, if you press the menu key and choose "Get Plain Text" it goes back to normal. That shouldn't be. I told the tech that OS 4.5 on the Curve 8330 didn't have this problem, so why would it become a problem in OS 4.7. He had no idea, but promised to pass this along, with my email examples, to the developers. I also emailed their "suggestion box", as noted in my post linked above.