REPLY TO ALL: How Can I Improve Email Rendering Across All Platforms?

Aside from testing, are there any minimal requirements that any email marketer can follow that will improve display on a Macs, PCs, and/or mobile devices? Or are there completely separate standards for each email client? —K.G.

The Voices of Email had this advice:

Deirdre Baird: First, ensure the HTML is valid according to either W3C or WDG standards. This is the single best protection for universal rendering.

Second, try to ensure the integrity of the message (branding, calls-to-action, etc.) are communicated even if images do not display. While alt tags are useful, they do not display universally in all email clients, so do not rely exclusively on alt tags as an alternative to image display.

And third—and this is more of an FYI—some mobile readers display the HTML version as text instead of displaying the Text part of a multi-part message (as many assume). If a significant percentage of recipients are assumed to be using mobile devices to read emails, then consider not only the text part of your multi-part but also what the HTML part will look like when rendered as text. If possible, ask customers at sign-up if they’d like a “mobile version” of the email and/or create a mobile version that folks can subscribe to.

Chip House: The goal is properly recognizing the differing needs of your subscribers and customizing the content and format to best meet their stated or observed needs. The first way to do this is to ask their preferences (HTML or text) at the time you capture the opt-in. If you don’t get that information, then you have to try to optimize for how you want your subscribers to use and/or respond to your communication.

Let’s look at mobile first. The challenge appears bigger than it actually is. For example, when you look at the total possible number of rendering combinations for mobile devices, which vary by mobile phone manufacturer, top ISPs, mobile data providers and mobile operating systems, you get 3,780 unique rendering possibilities. However, what we’ve found via our research is that 56% of users are less likely to read commercial email and/or newsletters on their mobile phone as they are on their laptop or desktop. The message there is you need to optimize the email for both the mobile and laptop/desktop computer environment. In fact, our testing showed that commercial email sent using multi-part MIME (includes both text and HTML parts) was the most versatile format. By this I mean it is most likely to render as HTML only for those systems that can display HTML well, and render as text elsewhere—such as on many mobile devices. However, the advantage of multi-part MIME over text here is that when a user saves or flags your email to look at it on their desktop/laptop, they’ll get the graphic-rich HTML version you’d love them to see—which is also likely to deliver a higher click rate.

Testing the rendering of your email campaigns across a number of email clients and ISPs is the best way to overcome the difference in those systems. We use Pivotal Veracity’s eDesign Optimizer heavily for this purpose, which allows for preview in a number of different mail clients (including Mac). Each has its own unique page break and image rendering rules, for example, which need to be optimized around. With a little testing, however, you’ll be able to get your HTML in tip-top shape for nearly all recipients.

Stephanie Miller: Let me focus on optimizing for mobile. What actually renders on a PDA or Smartphone is determined by four factors:
1. The operating system and software (e.g., Palm OS, Blackberry OS, Windows Mobile)
2. The service provider (e.g., Sprint, Verizon, T-mobile, etc.)
3. The device itself (e.g.: Treo, Blackberry, HP IPaq, iPhone, etc.)
4. The user’s settings

Yes, it’s messy. And totally different than reading email on a PC. There is a temptation to just deliver text to mobile users, but I don’t recommend this. First, because it’s hard to know who is a mobile user (there is unfortunately no “sniffer” that tells the sender what device is being used (PC vs. mobile). Second, because mobile users are not just mobile users. They also read email in their PC-based email clients, where a nicely formatted HTML email still yields higher responses in most cases.

The best bet is to rely on Marketing 101—Know Thy Customer. Ask subscribers if they regularly read your newsletter or promotions on their PDA. Many mobile device users sync their device back to the PC and read newsletters there rather than on the road. If you believe that many of your subscribers read your email on their mobile device, then offer a mobile-friendly format (simple HTML with text) that can be selected at sign up or in your preference center. If you believe that many of your subscribers are sometimes mobile readers but often PC readers, then format your HTML (particularly the masthead and preview pane) to minimize the number of image links and other code that readers must scroll past to see the actual content.

Have some good advice that we missed? Please add a comment and take part in the conversation.

Have a question for the Voices of Email? Email Chad your question at and we’ll REPLY TO ALL by posting the answers so everyone can benefit.

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