Hi Ferdinand and Welcome to WTT!
You are touching on a tricky subject. While there are certainly legitimate reasons for video emails, video spam is on the rise. And spamming is not looked upon favorably by those of us who are in the business of protecting IT consumers from Internet badguys. And we certainly do not want to assist the badguys either.
Assuming you are not intending on mass mailings of unsolicited video spam, I recommend you enter:
video emails in your favorite search engine and see what is out there first. Then come back with specific questions based on what it is you want to do. I think then, we can better assist you. We would need to know what you have to start with, in terms of existing hardware, skills, goals, etc.
Is it useful in Email Marketing?
If your company just created a new and useful product,
and your clients or customers have agreed to get promotional emails and company announcements directly from your company, then it could be a great marketing tool
if done professionally. It should be similar in quality to a television commercial. If it looks and sounds like it was done in a garage with a cell phone camera by a kid who flunked English, then forget it.
For me personally as a consumer, I hate them and automatically delete them without viewing. Video emails are a waste of my time and disk space. I can read text just fine, and look at still pictures much faster than a video. When I am going through my emails - and I get lots every day - fast is very good. If my attention is not caught immediately, it goes straight to the bit bucket. Generally, if you want me to "see" something, send a link. But of course,
Practicing Safe Computing dictates we, as disciplined users,
NEVER click on
unsolicited links.
From an IT consumer perspective, video emails can be very large, consume lots of bandwidth and increase download times. For users with limited, or pay by-the-byte Internet access, downloading video spam, errr, I mean video emails cost them money - not cool when unsolicited! Email already is said to be 80% spam, we don't need any more expensive bandwidth wasted by bandwidth hungry videos.
As a parent and grandparent, I am afraid. It is inevitable - children
will be killed by reckless drivers watching video emails instead of the road. It has probably already happened.

I will be particularly upset if (when - :() one my grandkids receives a pornographic video spam.
From the IT security perspective well aware of the downside of unsolicited email, and the malicious cargo it frequently carries, someone who sends mass mailings of unsolicited video emails is a spammer, akin to the scum at the bottom of a medieval cesspool. JMHO.
So, let us know what you discover and what specifically is still unclear and hopefully we can help, or at least get you pointed in right direction.