Email marketing is evolving to incorporate social sharing features. By adding social sharing buttons to emails, companies can generate additional exposure for their email content as recipients share messages through social networks like Facebook and Twitter. Case studies show this "social email" approach can increase open rates, click-through rates, and viral growth for email lists. To succeed with social email, companies should focus on creating shareworthy content that motivates recipients to easily spread messages through their social networks. Testing is important to identify what content and messaging resonates most.