Well-crafted video captures your viewer's attention in a way text can't, however, you should not directly embed video within your email marketing campaigns.
Instead, it is better to create a thumbnail of your video, with a play button and a link to your video.
This allows for your video to be accessible to your viewers without being penalized by email clients.
Why should I not embed video in my email?
Although not as seamless, an image and a link gives the benefits of an embedded video without the following issues.
Higher chance to be flagged as spam
Spam filters are sensitive to non-standard email content, especially email that contain large files like video. There is a chance the embedded videos in your email will get flagged as spam.
Not all email clients support video
Email applications, like the native iOS client, Apple Mail, and Outlook.com allows for video playback within the email, but Gmail and the Android devices will display a fallback image.
Your email marketing platform tracks open and click-through rates, but it stops there. If people don't leave their inbox, it's far more difficult to quantify their actions. Linking to a separate page provides more trackable actions and gives more data to optimize your emails.
No opportunity for further engagement
To expand on the above, if your users don't leave their inbox, you lose control of the viewer experience. If you place your video on a custom landing page, you have better control on the messaging, the call-to-action, user input, and interaction with your brand.