Note
You first need to create an email template with a video element.
- Double click into the video element. 
- A pop-up box appears.
 
 - Paste the link to your video. 
- This link needs to be copied from any video provider source that includes a thumbnail option.
 
 - Click Add Video.
 

Tip
Remember to frequently save your changes by clicking Save in the top right corner of the page. 
How Do I Find the YouTube Video Link?
- Navigate to youtube.com.
 - Use the search bar to find your video.
 - Under the video, click the SHARE button.
 - Next to the link, click Copy.