The recommended workaround to placing embedded content into the email is:
Embed or host the Flash Animation, Video or Form on an external webpage
Obtain an image of the animation/video, or a link to the Form (this could be done by taking a screenshot of the animation/video/form etc and then modifying this)
Insert the image into the email and then link this to the relevant webpage (or insert a link to the Form)
For example, if a screenshot of a YouTube video is taken, this could still show/display the play button. If the image is then inserted into the email and linked to the relevant webpage, when contacts view the email and click on the play button, the external webpage containing the embedded video would then display.
Alternatively, you may like to insert a text link to the relevant webpage.