New user approval setting went away after upgrading to 8. Now I have re-enabled it (via "Enable Registration Queue"), but I'm not getting emails asking to approve a new user. Where is the Administrator email address specified?

All other email is going through without any problem. When a user registers, they receive the email confirmation message.
I also tried "Send Email" (under "Tools & Information") and that email also goes through.

Also, where do I specify Google recaptcha keys in the Control Panel?

Thanks for your help.