Generating witty text... Get creative with emojis in email subject lines to increase open rates! Sit up straight. A mobile-responsive email can increase clicks by 15%. Always check mobile previews before sending out emails. Don’t forget to add a short preview description to encourage people to click on your email. Fighting off robots… 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.