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As you can see from the chart below – Apple is the only platform that supports Video in email reasonably well.  Gmail also previews youtube video in email. Here is a summary of video support in various email clients:

Adding Video to your Email Campaigns

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<video width="640" height="360" poster="http://www.yoursite.com/video-image.png" controls="controls">
        <source src="http://www.yoursite.com/yourvideo.mp4" type="video/mp4" />
        <a href="http://www.yoursite.com/"><img src=" http://www.yoursite.com/video-image.png  
         "width="640" height="360" /></a>
</video> 

Explanation of the Above Code

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All other clients will display the static fall-back image image — assuming that they are not blocking images.

References: 

• http://www.pinpointe.com/blog/embedding-video-in-email-overview
• http://www.pinpointe.com/blog/how-to-embed-video-in-email

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