An important part of email marketing is learning about what works and what doesn’t. Email provides instant feedback on your marketing efforts, feedback so instant, you can use it to determine your marketing efforts.
Running the A/B email test allows you to create two emails, with as small a difference as the subject line to the colours of the call to action buttons.
After a preliminary group gets either an A version or a B version, the software calculates based on your criteria which one is the winner. The rest of your group gets the winning email.