Hi Ray, all email notifications are sent to the email address defined in the admin main settings there isn't a way to define a different email address for specific store emails.
Is there a setting to send the admin email notifications when someone signs up for their monthly newsletter? If so, where do I find that setting or add to a settings file?
I'm pretty sure you could accomplish this by using the MailChimp integration. If your client's list isn't too large, they could use a free Mailchimp account.