Update: We've just completed some research into a new approach to video in email using the video element in HTML5. The results were very positive and give us a new and more reliable way to display video in email.
Many years ago most desktop and web-based email clients actually supported video in email. As security tightened and spam became a bigger problem, the belt was tightened and video support became a thing of the past.
With the proliferation of video on the web the past couple of years through improvements in software, bandwidth and available content, the email industry is again begging the question: can it be done? We decided to find out.
Just like the web, there is a range of different approaches you can take to try and display video in an email. Here's a list of the approaches I tried for the purpose of this test.
Thanks to its ubiquity and video quality, Flash has fast become the de facto standard for displaying video on the web. The default way for embedding Flash in a web page is via an OBJECT tag with an EMBED tag placed inside as a fallback mechanism. Because we can't use JavaScript in an email, there is no way to detect if Flash is installed and display alternate content instead. I tested Flash support in all the major email clients 3 years ago and the results weren't pretty. Perhaps some email clients have improved their support since then. We'll find out soon enough.
I was initially hesitant to try embedding techniques using players with less market penetration that relied on a specific player or operating system being installed. But, given the fact that Flash was so convincingly blocked in email clients, it seems anything is worth a try. Like Flash, Quicktime is typically inserted using the OBJECT and EMBED tags, so the results will likely be consistent with Flash.
Again, Windows Media files are also inserted using the OBJECT and EMBED tags. I'm not holding my breath.
Ahhh, animated GIFs. Is it just me or do you immediately picture a spinning globe on a Geocities site? Despite how old this technology is, recent tests indicate this is probably the most reliable way to include video in email. The obvious drawbacks here are file size, video quality and lack of audio.
Just like JavaScript and Flash, I had assumed that most email clients, either desktop, web or mobile wouldn't support Java applets. Only one way to find out. Java applets are embedded into a page via the APPLET tag.
Just like embedding images in email using base64 encoding, you can take the same approach with video. This approach does have its own limitations; the only way to embed a video in a HTML page without the object or embed tags is with the little known dynsrc attribute of the img tag. This tag isn't well known because it only works in Internet Explorer (and support has been dropped in IE8). From the start this approach is a long shot, but it should work in several version of Outlook (which uses IE as the rendering engine), and potentially to anyone using a web-based email client with IE.
Theoretically this should give them same results as referencing the image externally like in test number four above. But, embedding an image has been known to get around image blocking in some email clients, so I figured it would also be worth looking at.
To ensure all the popular web, desktop and mobile email clients were covered, I ran my test emails through the following email clients.
Desktop email clients
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Web-based email clients
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Mobile email clients
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Additional observations
While the results for the animated GIF tests were impressive, I did note the following issues:
To be honest, there weren't a lot of surprises here. The OBJECT and EMBED tags remain as poorly supported now as they were 3 years ago. This instantly wipes out Flash, Quicktime, and Windows Media formats. As predicted, Java support was also a no show.
The results are quite conclusive - the only reliable way to embed video in email is an animated GIF. While it does render across almost all environments, there are (unfortunately) considerable downsides:
Because of the large file size, we also had some deliverability issues related to the embedded animated GIF we tested. ISP's such as AOL and Yahoo wouldn't load the original animated GIF because of its file size. Externally referenced is certainly the way to go if your animated GIF runs for more than 5-10 seconds.
This test was performed purely to test the technical side of embedding video in email. What it didn't cover was if you should be embedding video in email at all. Instead of embedding it, the obvious alternative is simply linking to the video from your email. By opening your video in an external browser, you can use just about any of the techniques above and it will work reliably.
In the end, it comes down to a simple question. If you desperately need some kind of video in your email, animated GIF is the most reliable way to do it. If you require sound or decent video quality however, a link from your email to the video in question is certainly a better alternative.