This document provides 5 lessons on email marketing campaigns that businesses can learn from: 1) Make it easy for the audience to take action directly from the email without going to the website; 2) Offer rewards to encourage the audience to engage; 3) Seek feedback from the audience to have a two-way conversation; 4) Personalize the email for individual users, especially those who haven't engaged in a while; 5) Provide valuable information and suggestions to help solve the audience's problems.