You can follow several great email marketing newsletters for insights and tips. "The Daily Carnage" offers a daily digest of marketing news and trends. "Email on Acid" shares expert advice on email design and development. "Campaign Monitor" provides useful guides and strategies for email campaigns. "Litmus" offers email marketing best practices and testing tips. "Really Good Emails" showcases email design inspiration and examples. "The Email Geek" is perfect for those interested in technical aspects of email marketing. These newsletters help you stay updated and improve your email marketing skills. Following them can lead to better campaigns.