UPDATE: FeedBlitz will now automatically produce video thumbnails for you if you use standard embedding codes from video sharing sites such as YouTube, Metacafe, Dailymotion, Blip.tv, Yahoo Videos, Hulu and more. See http://blog.feedblitz.com/2010/03/better-video-in-emails.html.
For other embedded videos, it doesn’t work because embedded video players built for the web are almost always what are called “active” components. They are powered by script, Java or third-party add-ins such as Flash, and use HTML tags such as <embed>, <object> and <script> to define them.
This works great on the web, but not so much in email.
The reason for this is that most modern email software treats active components in HTML email as potentially hostile (i.e. a virus or some other malware). They don’t “know” that the active component is a harmless video player. As a result, erring on the side of caution, almost all email software programs and webmail services will simply remove the video player before they display the email to the recipient. It may be possible for the recipient to override this by loosening up their email software’s security restrictions, but most don’t and those that do may not understand the additional security risks they are exposing heir systems to. It’s usually best for them to leave this particular setting as is.
Moreover, different email applications will remove the video player in different ways. Some will eliminate the space entirely, which will move any text below the player up. Others will leave a blank space in the email where the video player should have been, choosing to try to preserve the original email’s layout at the cost of inserting a large amount of whitespace. It’s up to the receiving email software to choose what to do. FeedBlitz does not control this.
If you use video a lot on your site and in your mailings, the best (and simplest) thing to do is remember to add a simple link just before or just after the video player in your article if your player isn’t supported by FeedBlitz’s automatic video thumbnail feature. The text you add might say something like “If you have trouble seeing the video, click here to view it online” and you make it a link to the video on the web. That way, email and RSS subscribers whose security policies forbid active content (and, remember, for email that’s the vast majority of them) can still view your video with a single click.