17. Rich Media/Flash in Email Message
The animated gif’s will not be displayed on outlook, When you receive an e-mail message that contains animated graphics, such as animated .gif files, only a static image appears on outlook.
Please refer to the link : http://office.microsoft.com/en-us/outlook/HA102014391033.aspx
You can also look at converting your flash files to animated gif images and then link to the flash website through the link click, so that users can visit the web page for a good streaming experience.
Read earlier blogs on the subject “Guide to a Better HTML Email Design” on Kenscio Blog.