Please enable some sort of end date for webinars so that I no longer continue to receive email registrations for a webinar that has already happened. There must be some way to disable that registration URL or close the webinar. I continue to recieve notifications of people that register for a webinar that took place in July 2018. Somehow folks are finding the URLs and trying to register. Please disable URLs for past webinars or add an 'end date' to the webinar that will no longer allow registrations.
If you can edit that webinar in your history, you may either remove the video linked to it (uses the original webinar registration link), or disable the notification to Organizers on the Registration settings themselves.