Yahoo & Gmail And Janrain, Oh My!

I received a yahoo group message out of the blue in my gmail. This has never happened before and I have always kept my yahoo account separate, that is I don't think I ever gave them my gmail as a backup. This message does NOT appear in my yahoo mail. I checked my settings and I see no backup address. What I do see is a Janrain Authentication program that I supposedly opted into, though I'm certain that never happened. I changed my password after the data breach news last year but I suspect something weird is going on. Google searches only seem to bring up issues for people who want Janrain to work for them. I seem to be alone in my suspicion. Any thoughts? Has this happened to anyone else?
Thanks,
P'lite

 

I have Yahoo, Gmail, Hotmail, Inbox and Yandex email accounts. Some are intertwined for recovery. I do get "You have checked in on an unknown device" because I use several different mobile and fixed devices and also different browsers. The companies have good accurate checking as far as I see. And I never have had the exact same message ever.