Design your email by clicking on one of the existing email campaigns that appear in the list. Once you have selected one you will enter the detailed view page that is specific to your email campaign.
There, click on the design tab -> Edit template button to start designing your email campaign.
This button will redirect you to the email builder which will let you create the perfect email design. You can choose from a variety of sections to reach the highest level of design personalization. Once your email is complete, don't forget to click on Publish to be able to send it.