Selected answers from the Dumb SEO Questions Facebook & G+ community.
Wakefly, Inc.: What is the best way to track emails through Google Analytics?
Mike Stetzer: If you've got links in the email, you can append UTM parameters on the URLs. This will only show you visitors that land on your page from emails, though.
Shawn Cohen: You might have seen this, but here's the GA Analytics Academy video on tagging ;https://analyticsacademy.withgoogle.com/unit?unit=4&lesson=5