"Grasping your audience's attention is the key way of optimizing email marketing opens. In order to do so, subject lines are the most important, but what some companies don't take advantage of is the subheaders. Think of it as a second subject line with extra space to include more information about your email. Making sure that the entire line shows up on a mobile inbox is also necessary, as most people today access their email on their phones." "A simple but effective thing to do is placing the important and enticing deal as the first part of your subject line. Besides aesthetic details, testing your email through platforms to make sure it doesn't go to the spam folder is a good idea, along with making sure all the loops are figured out for deliverability, which in turn optimize opens."