Mobile optimisation
Mobile optimisation in email is the practice of designing and coding email messages so they render correctly, load quickly, and are easy to interact with on smartphones and tablets. With the majority of email opens now occurring on mobile devices in most markets, an email that is not optimised for mobile is an email that is not optimised at all. Mobile-optimised emails adapt their layout, font sizes, button dimensions, and image handling to suit small screens and touch-based navigation.
The core techniques for mobile email optimisation include: using a single-column layout that does not require horizontal scrolling, setting minimum font sizes of at least 14px for body text and 22px for headlines, making call-to-action buttons large enough to tap comfortably (at least 44 pixels tall), ensuring images are sized to scale within the screen width, and using media queries or fluid design to trigger layout changes at mobile breakpoints. Testing across both desktop and mobile views before every send is essential.
For B2B email marketers, mobile optimisation also means rethinking copy length and structure. Mobile readers scan quickly and in short bursts. Subject lines should communicate value within the first 30 to 40 characters visible on a mobile preview. The first sentence of the email body needs to justify continued reading immediately. And the primary call to action should appear early enough that a reader does not need to scroll far to reach it. Mobile optimisation is as much a writing discipline as a design one.
What percentage of emails are opened on mobile?
The proportion varies by industry, audience, and email type, but most industry research places mobile email opens between 40 and 60 percent of total opens across B2B and B2C combined. In B2B specifically, the split is influenced heavily by whether recipients are reading on personal phones versus corporate devices. Checking the email client breakdown in your own platform’s reporting gives you the most accurate picture for your specific audience, and is the right starting point for understanding how to prioritise mobile optimisation efforts.
What is the difference between responsive email design and mobile optimisation?
Responsive email design is a technical approach that uses CSS media queries to change the layout of an email at specific screen width breakpoints. Mobile optimisation is a broader practice that includes responsive design but also covers content decisions, writing style, button sizing, font size, image handling, and load time. An email can be technically responsive (the layout adapts) but still poorly optimised for mobile if the font is too small to read, the buttons are too small to tap, or the content is too long for a mobile reading context.
How do I test my email on mobile before sending?
Most email marketing platforms include a mobile preview mode that simulates how your email will look on a smartphone. For more accurate testing, tools like Litmus and Email on Acid render your email across dozens of real device and client combinations simultaneously. You can also send a test email to yourself and open it on your own phone. Pay particular attention to font sizes, button tap target sizes, image scaling, and whether the primary call to action is visible without excessive scrolling.