Starting November 20, UCSC will have the option to try out Google's new email compose and reply experience. If you use Google's Gmail web interface for your UCSC email account, when you click the Compose button, click the "new compose experience" link right next to the Labels button. Until the change is fully launched, you'll be able to choose whether you use this new feature now or stick to the old design.
More details about this new release at: Google's New Email Experience
Instead of taking up your entire email window, clicking Compose will open a smaller window at the bottom of your screen.