Mobile email is a major challenge for businesses as studies have shown that as much as 50% of marketing messages are opened on mobile devices.

Obviously the precise figure varies drastically from company to company, so the need to optimise for mobile will be less important for some businesses.

But even so, it’s an issue that all businesses will have to deal with at some point in the next year or so.

One option for dealing with mobile email is responsive design, which uses one set of code that renders an email differently when viewed on a desktop, tablet or smartphone.

This means that the user experience is optimised regardless of where and when the recipient decides to open the email.

It seems that this utopia is far from coming a reality though, as our Email Marketing Census shows that a large number of companies do not have any strategy in place for optimising email for mobile devices, with 32% reporting this as ‘non-existent’, and 39% saying their strategy was ‘basic’.

For companies in the process of working out how to optimise their emails for mobile, I thought it would be useful to round up a few case studies looking at how responsive design impacts user engagement.

So without further ado, here are the case studies plus a bonus infographic...

CareerBuilder increased CTR by 20%

After implementing responsive email design through ExactTarget’s platform, CareerBuilder achieved a 15%-17% increase in open rates and a 21%-24% increase in CTR.

It’s difficult to think of any reason why the open rate would increase due to responsive design, so this could be due to subject line optimisation.

Weird Fish achieved 10% increase in CTR

It’s a case study that’s slim on details, but Weird Fish increased the CTR to its website by adopting responsive email templates.



When DEG Digital created responsive emails for shoe retailer Crocs it began with a testing plan to learn and optimise the results of the redesign.

In the first test it created a three-way creative divided:

  • Group A received a static desktop version.
  • Group B received a static mobile version.
  • Group C received a responsive email design.

In this test clicks and opens were largely consistent for all three versions, but were slightly higher for the responsive design.

  • Total revenue and revenue per email were highest for responsive, followed by desktop, and then mobile.
  • Responsive and desktop achieved the highest AOV.

In the second test Crocs used an email that was less discount-focused and modified the way it tracked links to achieve more accurate results.

The test was a 50/50 split with one half receiving a desktop email and the other half a responsive email.

The results:

  • Responsive showed an overall 7.66% lift in click-to-open rate.
  • iPhone ‘read’ engagement had a 15.63% lift for the responsive version over the desktop version. Crocs is seeing more than 25% of all opens occurring on iPhone which makes optimising for this device even more important.
  • Mobile ‘read’ engagement had an 8.82% lift for the responsive version over desktop version.
  • Revenue on the mobile site was consistent for both versions.
  • Revenue on the desktop site was lower for the responsive version (since this test Crocs has launched a new responsive design website).


Footwear manufacturer Deckers, which owns several brands, moved to responsive email design when it realised that between 35% and 65% of its subscribers were opening their email on mobile devices.

But before committing to responsive design it ran an A/B test with its Tsubo brand, which had about 37% of its subscribers opening email on mobile devices.

The results of these A/B tests definitely leaned in favour of using responsive design. The emails that used media queries saw a:

  • 10% increase in click-through rates
  • 9% increase in mobile opens (iPhone opens went from 15% to 18%).

Deckers now uses responsive design for several of its brands. 

Userlicious also achieved 10% increase in CTR

Userlicious redesigned one of its client’s emails using a responsive template, coming up with this basic design: 

The intention was to design its emails for fat fingers and a small screen, including a limited amount of copy and shadows around the edges of the images to make them look like clickable buttons. The result was a 10% increase in CTR.

Scalable vs. responsive email design infographic

David Moth

Published 17 October, 2013 by David Moth

David Moth is Editor and Head of Social at Econsultancy. You can follow him on Twitter or connect via LinkedIn

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Comments (8)

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Joe Hawkes

Excellent article!

It's a amazing what you can do with a few simple media queries in the code of an email. It still surprises me that in 2013 many companies still aren't optimising their emails for mobile and tablet devices.

almost 5 years ago


Morgan Jones, Digital Manager at Myself

I'll tell you why more companies/agencies don't do it. It's because for years they have been charging the client one rate for a static layout. Now that the landscape has shifted they (the agencies) are afraid of charging clients more money for essentially the 'same thing'. The client cannot see the value in it and will ask the question 'why should I pay more?' Their expectation is that the agency should be doing it this way anyway so should suck it up or the client will take their business elsewhere. In turn the agencies will not allow more time for the designers and developers to do an effective eshot/campaign ergo we are stuck with producing communications that satisfy neither brief or technical requirements.

almost 5 years ago



Are are any great resources or templates out there to learn responsive design?

I'm having trouble getting basic media queries to work for a basic 2 column template with one hero image at the top.

thanks all

almost 5 years ago


Vijayasarathy Dhanasekaran

Very good informaiton

almost 5 years ago



Great article... but before you go down the responsive route it is a good idea to see if your users are actually viewing your emails on a mobile device. Luckily this is very easy to do with an analytics tool such as Litmus. You might be surprised with the data you get back.

almost 5 years ago



I understand and believe that Responsive Email Design is theorically the ideal technic to the best rendering of our emails on mobile devices. But when it comes to the real scenario, I realize that many of the mobile devices and email providers show several problems rendering responsive emails. And it's not easy enough to combine scalable and responsive technics to make an email look good in all of them, actually, sometimes it's a real headache. So, although I think Responsive should be the path to go, I wonder, if it's worth the effort today. I find it difficult to convince clients that Responsive Design should be used, when, for example Gmail won't read the <style> tag.
If I could use a mix of thechnics as told here, It should work, but then I find that inline styles for Gmail will fight my <style> tag and many other problems.
¿How do you deal with that?
Thanks for the article :)

almost 5 years ago

Robert McWhirter

Robert McWhirter, Browser London

Hey, I would be interested in hearing you thoughts on images in email...

Since many email clients (particularly mobile clients) block images by default, surely we should think very carefully before filling emails with great big images. From personal experience I know that an email full of alt attributes and blank space goes straight in the trash.

With this in mind, is there an argument to keep emails largely text based? Simpler to build and better user experience across all screen sizes.

(Some email client stats here:

almost 5 years ago


Miles Date, Dialogue marketing at Dialogue marketing

Some might think that responsive email allone is going to greatly improve your email results. In that respect it might just be, the shiney (somewhat) new thing.

over 4 years ago

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