71.5% of consumers most often check their email on a mobile device. If you want subscribers to engage with your email campaigns, you’d better deliver mobile-friendly, responsive email designs. Period.
But what do you do when, despite following all email design practices, some recipients can’t open your email?
It’s not a rare day when that happens. In fact, it’s bound to happen when you skip designing responsive emails.
Without the responsive design, emails don’t display correctly on different devices and screen sizes. Rather, getting your email templates to display optimally across different devices is as important as checking their renderability on Gmail and Outlook.
That way, you know that your email templates are functional and earn you the maximum opportunities for click-through.
On the contrary, if you're not testing email templates for responsiveness properly, you're essentially playing Russian roulette with your brand's reputation.
So, let’s understand how to test your mobile-optimized email templates so that you spot inconsistencies before hitting send.

What Is A Responsive Email Template?
A responsive, mobile-optimized email template is a pre-built email template designed to be functional irrespective of your email recipients' device.
If you can access responsive email template services, custom, responsive email template design shouldn’t be difficult. Else, no-code, dag-and-drop email builders should get the job done.
With mobile-optimized email templates, you can craft professional-quality, visually appealing emails with zero coding knowledge. Plus, templates are reusable. You can save your designs, making it easier to scale mobile-friendly designs as and when needed.
Just as not optimizing emails for viewing beyond the desktop could make you lose a huge chunk of your audience, emails that don’t display reliably on different devices can strain your budget and long-term strategy. View every unsubscribe from a frustrated mobile user as money walking out the door.
But how do you know how the email will render on apps and devices growing faster than your laundry pile on a Sunday? Let’s find out.
How to Check Responsiveness of Your Mobile-optimized Email Templates
Test Them Practically
The most reliable method for ensuring your responsive email templates render perfect across devices is deceptively simple: test them practically on these devices.
Practical testing of mobile-optimized email templates means sending emails to various test accounts across different email services. That’s essential because email clients and devices can display your emails differently. And you want to ensure that the email looks and functions as intended.
To start, set up test accounts with popular browser-based email services. Gmail, Yahoo!, and Outlook should be at the top of your list.
Pro tip: you can set up a Gmail account to forward emails to your other test accounts. That way, reviewing how each ESP handles your emails is easier without logging into multiple accounts.
To tune your email coding and design more accurately, use browser-based tools like Firefox's "FireBug" or other code inspectors. They let you peek under the hood to see how your HTML and CSS are being interpreted (or misinterpreted).
When testing responsive email templates, focus on the most popular email client platforms. Think Outlook, Yahoo! Mail, Gmail, Apple Mail on iOS and macOS devices, and Google Android email clients.
If possible, test on additional platforms to cover more ground. It pays to see that your email looks great and functions well across all clients.
Built-in Email Previews Of ESPs
An ESP or email service provider is a tool that email marketers use to create and send email campaigns to subscribers. Think Mailchimp, Campaign Monitor, Klaviyo, HubSpot, etc.
Understanding the need to send responsive emails, many modern ESPs show you email design previews on subscribers’ devices and email clients. The previews are screenshots of how an email template renders on desktop, mobile, and tablet.
So, if the template is responsive perfectly to T, it would function properly on these devices. If not, you can catch those problems in email previews.
Third-Party Testing Tools
For email marketers who sleep better with thoroughness, third-party testing services like Email on Acid and Litmus offer the digital equivalent of hiring a quality control team to test the responsiveness of email templates.
They test your emails thoroughly across a wide range of email clients, browsers, and operating systems.
This is far beyond what you can achieve with practical testing or previewing alone. The detailed previews and analytics that save time and reduce stress make every penny worth it.
These tools simulate how your email will appear on dozens of email clients. And for variations in operating systems (Windows, macOS, Android, iOS) and browsers? Yes, that too!
That’s handy because you may not have access to all these combinations yourself. For example, an email that looks perfect on Gmail in a web browser but has broken layouts or missing images when viewed in Outlook on a desktop or Yahoo Mail on a mobile device.
Third-party tools help you spot and fix such issues before sending your campaign.
Additional features like spam testing, optimization checks, and deliverability analysis are other perks of such testing tools.
That’s not to say that they are a replacement for practical testing. Practical testing gives you hands-on experience with how emails behave in real-world scenarios.
So, the most thorough approach to testing responsive email templates is combining practical testing with third-party tools.
Wrapping Up
Responsive email templates have a better chance of displaying correctly across screen sizes, ESPs, operating systems, email clients, and image settings. Since they are pleasant to interact with, you make it easy for your subscribers to read and take action. Whether that means reading your newsletter, clicking your links, or purchasing. Ultimately driving higher engagement and more sales.
Readers who find your emails difficult to read on mobile devices will have limited engagement. They will quickly unsubscribe or may even report your email as spam.
When you commit to mobile-optimized email templates, no matter how they’re viewed, your email campaign performance metrics will improve.
The key is a testing workflow that seamlessly integrates into your email design and development process. Not as an afterthought. That way, you can create and test complex coding to ensure device compatibility.