Sending any attachments makes your email way more likely to be marked as spam by your contact’s email provider.
Moreover, most email clients (like Gmail, Outlook, and Yahoo Mail) do not support embedded video so they won't display it.
Even it’s harder to track views since your contact doesn’t click through to a new page.
Create a screenshot or thumbnail for your video
Add a play button icon to your screenshot (it makes people click through to watch the video)
Insert an Image element to your email and upload your picture.
At the right side of the screen you'll see the IMAGE BLOCK SETTINGS, go to LINK TO WEBSITE and type the link wherever the video is hosted
Add an Alt/Title if needed
When contacts receive your email, they will be able to click on the pic and will go straight to your video.
To jazz up your email, you can also use an animated GIF with a few frames of your video rather than a static screenshot.