Impossible to unsubscribe !?!?!?

For some reason, I cannot unsubscribe from this mailing list.
When I use the web page, I am redirected to a login page from google (where
my email is not registered)
When I use emails to unsubscribe, the email bounces (see below)

Please help.

Well, the email you are using now for this email is not subscribed. Give me your email that is under the subscription and I will be glad to erase you.

Gerald

OK, You have now been erased!

Gerald