Embedded video commonly refers to the use of video within an email for marketing purpose.
Embedding video has been an issue for many years in email marketing context as video rendering in email clients is often erratic. However, technical barriers have been recently and partially removed with adoption of HTML5.
Embedding video principles are the same as for YouTube video integration. The video is offered and viewed within the email, but it is hosted on the web on the advertiser website or on YouTube channel.
There are still many questions and issues with embedded video in email.
all email clients and services are not able to read videos
video may be filtered by some antispam solutions
To see more about benefits of video in email and other techniques see email in video.
Some examples of embedded videos :