Get creative with emojis in email subject lines to increase open rates! Keep your email subject line short and attention-grabbing. Don’t forget to add a short preview description to encourage people to click on your email. Sit up straight. One Mississippi, two Mississippi… 51% of emails are opened on mobile devices - don’t forget to check the mobile preview for your email! Don’t forget to add a fun, relevant call-to-action button to your email. Try different email subject line styles to find what gets the most opens.