• by Chad White , March 2, 2010

Retailers who only check their rendering using Internet Explorer got a wake-up call yesterday when we released new research showing that the majority of major online retailers suffered rendering issues when their emails were viewed in Hotmail using Firefox. While the rendering issues were sometimes subtle, many other times the rendering severely deformed affected emails.

What's clear is that too many marketers aren't paying enough attention to how their emails are rendering across all the email client and browser combinations. Rendering's tough to stay on top of, because issues can arise from a variety of sources:

Updated email clients and new functionality. "Improvements" in email clients can release suddenly and can impact a significant slice of your subscriber base. For instance, Gmail made the decision in January to default to HTTPS for all emails. In announcing the change, Google talks about sacrificing some speed for greater security. But what the company didn't acknowledge is that people viewing Gmail with Internet Explorer get constant -- and poorly worded -- security warnings about nonsecure content. If you're hosting your images on nonsecure servers, then you've likely seen a dip in opens among your Gmail subscribers due to blocked images because of this switch to HTTPS.

Another improvement that hurt rendering was the introduction of Gmail Themes back in late 2008. If you didn't define all your background, text and link colors, certain Themes like "Contrast Black" could make your beautiful email design nearly illegible. At the time, my estimation was that approximately 40% of all retailers had the potential to be significantly affected by this rendering problem.

Of course, in the not-too-distant future, we can look forward to Outlook 2010 perpetuating all of the rendering challenges that arose with Outlook 2007. Although the company has softened its stance a bit, Microsoft clearly has no sympathy for email marketers or HTML standards.

New email clients. In addition to updated email clients, we've also had to deal with the arrival of completely new inboxes, including the iPhone and more recently MySpace Mail. And of course, we'll soon have Facebook Mail to contend with, as well.

New and updated browsers. As we've seen with the Hotmail-Firefox and Gmail-Internet Explorer examples above, browsers can be just as problematic as email clients. New browsers like Chrome complicate rendering X fold, as you have to test it with every email client to look for issues. And of course, legacy browsers are also a source of issues. For instance, Internet Explorer 6 has been a plentiful source of rendering problems for years.

With inbox functionality expanding to allow rich media like video, greater browsing capabilities, and even in-email transactions, there will be many more opportunities for email rendering and functionality to break in the future. Now is the time to get a handle on rendering and to ensure that your template is bulletproof in every email client and every browser.