Can't share family tree because they have comcast and verizon e-mails?

Just to be clear - are you talking about, cannot invite them to join Geni by putting their e-mail in the e-mail field on their profile -- or about clicking on "Family" on top row of screen, between "Tree" and "Research" -- getting the Drop Down Menu there, and then choosing "Share Your Tree"?
-- and if the latter, which of the four boxes you then see are you talking about?

We've had this problem in the past with invitees. We had to give up.

This may shed some light...

http://help.geni.com/hc/en-us/community/posts/222064227-whats-the-d...