Sending a single Invitation to multiple family members

I have more than a 1000 living relatives in my geni tree. I want them to update their individual profiles, which have not been touched in at least 10 years. How do I send
a single invitation that will go to all of them?

Start a Family Discussion. All claimed profiles in your family group will receive notification that you have started a family discussion.

That might not hit all 1000 as some of those may be outside your family group, but it's the closest option Geni has.

I wouldn't want any option that gives someone the ability to spam my family.