A picture may be worth a thousand words, but good email copy is invaluable. Check out this article from the HubSpot Blog that contains plenty of tips for leveling up the quality of your email copy. 

Highlights include:

• Use actionable language
• Prioritize clarity, and only then think about "catchiness"
• Talk about benefits, not features (ie programs/news)
• Be brief

You can read the full article here.