There's an unsubscribe link, but it directs me to login to my account to manage my e-mail preferences -- I don't have an account. They have a separate, hard to find, "remove me from your invitations" form, but they seem to ignore that. I finally sent a CCPA request (very hard to find the link), which went unacknowledged, but the e-mails seemed to stop until recently, when they started again.
The kicker is that they think I'm someone else (a relative), so it's all completely ridiculous.