Try the info at the link
Blessings on you, rescuer--you are always quick to respond with help for us. This time I have printed the instructions to save, as my memory won't!. Thank you so much for the site.
If you didn't sign up for the group, it might be only about spamming you. I would not open and would put in spam. I've had two or three try to welcome me to a group I don't know.
I never signed up for any Google groups--do not wish to participate in any of them. I have gmail on another device, and Google browser on my desktop--that's the extent of my participation, but 'liberties' are taken. You should see (no you shouldn't!) the obscene mail I get daily from women wanting to 'hook up' from other countries. They don't care that I'm a woman too. Someone sold them my address. It is such a hassle to change it, so I delete and delete--hoping they will stop someday.