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. Boost your email opens with a punchy subject line. Get creative with emojis in email subject lines to increase open rates! Generating witty text... Feel free to spin in your chair while you wait 51% of emails are opened on mobile devices - don’t forget to check the mobile preview for your email! Keep your email subject line short and attention-grabbing.