I am the host. It is my server. There are no errors generated. If "firstname.lastname@example.org" is used as either the CC or BCC the email is received. If that same email address is used as the shopper's email, and others are used for cc and BCC, the shopper email is not sent. The shopper's email for Email verification and Registration emails is never sent. It is not trapped in the spam filter.
I do not think Powerstore is picking up the shopper's email address from the registration form when it is filled out by the shopper.