One Mississippi, two Mississippi… Don’t forget to add a fun, relevant call-to-action button to your email. Test, test, and test again! Make sure your email looks good on all devices before you send it out. Keep your email subject line short and attention-grabbing. 51% of emails are opened on mobile devices - don’t forget to check the mobile preview for your email! Join 4 million members in making awesome marketing content. Fighting off robots… Boost your email opens with a punchy subject line.