What happens when we send the emails to this type of addresses ended with @phone.punchh.com?
Guests whose names appear in your list as "Guest User" are guests who have signed up for your loyalty program via POS using only their phone number.
@phone.punchh.com will not send emails to the guest user as this is not any Guest's actual email address. It is a generic email association created automaticly when signed up via phone number at the POS
These users have not yet signed up using the mobile app, therefore there isn't much available information to show about them.