A/B testing is a terrific tool for determining the most effective email marketing strategies and timing for your unique audience and situation. Everything in your email, from the template to the subject line to the headline, may be tested. In order to get you started, here's a list of some suggestions: Message in subject line Design of the message's layout (one-column or two) Personalization is an important part of any marketing plan. Call-to-action Headline Images Time of day/day of the week You should only test one variable at a time so that the results are obvious as to which variables worked and which did not. My recommendation is to test on a constant basis since there is always opportunity for improvement. It seems like there is always something new to learn and experiment with in the world of email marketing. It is hoped that these email marketing questions and answers will help you get off to a strong start.