It's only recently that some email providers have begun to support videos within email.
With allContact though, you have every base covered. If the email client doesn't support video directly, our system creates a still frame from the video, and overlays a play button. When clicked, the page hosting the video loads, and the video begins to play.
It's a good idea to incorporate "video emails" into your overall marketing mix, as the click thru rates are often very high. You'll find the Add Video button in our email editor toolbar.