If the merchant insists on sending video-based emails to serve the few customers who will be able to view them, they can follow the steps below:
This article covers how to embed videos to play directly inside emails as opposed to tapping a thumbnail to link to the video hosted someplace else (Vimeo, Youtube etc.) Users should be aware that support for video inside of email is weak at the current time and is not widely supported. The best bet is to use the built-in video content box by dragging the Video block from the CONTENT panel of the email editor and complete the hyperlink setup. Read Adding Video Content Blocks to Campaigns for best practice guidance.
If the merchant insists on sending video-based emails to serve the few customers who will be able to view them, they can follow the steps below:
For more information on the HTML5 video element, see https://www.w3schools.com/html/html5_video.asp
For the recommended way to display video in campaigns use the Video content block. See Adding Video Content Blocks to Campaigns for instructions.