Feel free to spin in your chair while you wait Sit up straight. [insert fun loading text here] Get creative with emojis in email subject lines to increase open rates! Let your imagination run wild. 51% of emails are opened on mobile devices - don’t forget to check the mobile preview for your email! Try different email subject line styles to find what gets the most opens. A mobile-responsive email can increase clicks by 15%. Always check mobile previews before sending out emails.