One Mississippi, two Mississippi… Keep your email subject line short and attention-grabbing. “Everything I have designed has a crisp professional look and feel. Love this service” - Cameron Sit up straight. Don’t forget to add a fun, relevant call-to-action button to your email. 51% of emails are opened on mobile devices - don’t forget to check the mobile preview for your email! Boost your email opens with a punchy subject line. Let your imagination run wild.