Stream?
You receive an e-mail at any time, not necessarily the one in which the stream is currently running.
You can add recording to movie or link to connect stream, you can send invitation to meeting or add attachment with calendar event.
Usually mail creator paste picture and link it to movie like:
To understand how mail's code works I wrote Outlook add-in to look inside, change some or create new mail: utworz-maila-z-kodu-html so I can recommend you that.
To add calendar event where you do not know all recipients by name I recommend you this: translate
Redards