code: def get_default_recipients(self):
          ''' Overrides EmailRecipientMixin '''
          if self.email:
              return [self.email,]
          if self.finalRegistration:
              return [self.finalRegistration.customer.email,]
          elif self.temporaryRegistration:
              return [self.temporaryRegistration.email,]
          return [f get_default_recipients(self):
          ''' Overrides EmailRecipientMixin '''
          if self.email:
              return [self.email,]
          if self.finalRegistration:
              return [self.finalRegistration.customer.email,]
          elif self.temporaryRegistration:
              return [self.temporaryRegistration.email,]
          return []
docs: Overrides EmailRecipientMixin