51% of emails are opened on mobile devices - don’t forget to check the mobile preview for your email! One Mississippi, two Mississippi… Keep your email subject line short and attention-grabbing. A mobile-responsive email can increase clicks by 15%. Always check mobile previews before sending out emails. Not just a pretty interface Time to get that bread. Boost your email opens with a punchy subject line. Try different email subject line styles to find what gets the most opens.