Hey @tpSignal88 due to spam and security reasons, video is not supported in email across some major email clients, such as Gmail and Yahoo. As such HubSpot does not currently plan to introduce this feature.
If you have selected to have a webpage version of their email, you can use the webpage URL to hyperlink your video’s screenshot.
If you’re integrated with Wistia, here’s a tutorial on how to link to Wistia videos in HubSpot emails.