Due to limitations in most email clients, it is not possible to directly embed videos email templets. Instead, you can share the video in three other ways.
1. Link to the external page where the video is embedded through a hyperlink in photo or text.
2. Link to a Upsales landing page where the video is embedded (Landing pages supports Vimeo and YouTube videos)
3. If the file size of the video is below 25MB, you can include the video as an attachment. Both in emails campaigns and one-to-one emails.
One one-to-one emails you find the attachment option in the subject row.