We've featured the strength of Dropbox emails before for onboarding, refer-a-friend campaigns, and group sales. Here's their renewal reminder, which we think is just as strong. We like that they've updated their look a bit with, but note the text, which is still concise, easy to skim because of bold text, and hyperlinked. Some repeat links to the same page might help conversions with some sites, but given the brevity of this message, we think Dropbox did well to leave it at one....