Anna, one of the Admins here, posted on my thread in the Troubleshooting forum that she has no idea how this could happen. She assured me they will look into it immediately.
I told her I can send her the email I received--which has attached the email SR sent to the other member disclosing my email address.
I suspect all that needs to be done is to change the content of the automatic emails, but geeze--pretty big goof.