Coding your Emails

Chapter 4

What Other Technologies Can You Use in HTML Email?

The modern Web contains a lot more than HTML, CSS, and images. JavaScript, audio, Flash, video, animations, and forms are all part of a designer’s toolkit. Which of these work in email clients? This section outlines the current state of play.

What Technologies Should You Use?

Even if you can use a certain technique or medium, you might not want to. People go to your website by choice, typically: they go when they want to and with an understanding of what to expect. An email is an entirely different environment from a website (as discussed in the section called “The Design Environment for Email” in Chapter 3), and having sound or video playing inside an email is more likely to irritate than entertain.

For some emails and some subscribers it might be okay, but be very cautious about disrupting your readers’ expectations.

Scripting in Emails

The short answer is that scripting is unsupported in emails. This is hardly surprising, given the obvious security risks involved with a script running inside an application that has all that personal information stored in it.

Webmail clients are mostly running the interface in JavaScript and are not keen on your email interfering with that, and desktop client filters often consider JavaScript to be an indicator of spam or phishing emails.

Even in the cases where it might run, there really is little benefit to scripting in emails. Keep your emails as straight HTML and CSS, and avoid the hassle.


In the web browser market, Adobe Flash is almost ubiquitous (except on iPhones and iPads, of course), but in the email client world Flash is barely existent. In most cases it’s completely absent, and even the fallback image you can select won’t show up.

The details of the current level of Flash support are shown in this resource ›

Using Flash in your emails should be avoided for the present, as it just doesn’t work. Unsurprisingly, this has a considerable influence on the effectiveness of video in email, which is our next topic.


Video can be a very persuasive medium—presenting action rather than just showing a static photo or text description. Whether people actually want to be watching a video in their email rather than on a website is an open question.

As of 2010, there are a lot of different ways that video theoretically could be included in an email message, but in practice most of them won’t work for the majority of recipients. Campaign Monitor has tested the following techniques and formats for live video in an email: Flash, QuickTime,Windows Media, animated GIFs (streamed and embedded), Java Applets, embedded MPEGs, and streamed HTML5 video.

The detailed results are shown in this resource ›

As you'll see, animated GIFs do have solid support, although they’re still subject to image blocking just like static images. In addition, Outlook 2007 will only show the first frame of the animation.

Personally I recommend a still simpler approach: take a screengrab of your video with the player chrome (and ideally a big honking “play” button), and put that into your email. Make it a link to view the video on your website (and link up a caption underneath it too). It’s one additional click, but it’s guaranteed to work for everyone.


Having an email contain a live form is a great idea—it’s easy for your readers to fill in some details and RSVP, or answer a survey. Unfortunately, the support for forms in email clients is quite inconsistent. Some clients will put up scary-looking security warnings when the reader tries to use a form, and others will just disable the form so it’s unable to be sent.

A lot of people might be able to use a form, but the rest will see a form that does nothing at all, which is a fairly bad experience. Again, the recommended approach is to link to a form on your website, where you know it will work.

The level of form support in common clients is shown in this resource › Testing

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