code: def _only_safe_emails(self, emails):
          Given a list of emails, checks whether they are all in the white
          list."""
  
          email_modified = False
          if any(not self._is_whitelisted(email) for email in emails):
              email_modified = True
              emails = [email for email in emails if self._is_whitelisted(email)]
              if settings.SAFE_EMAIL_RECIPIENT not in emails:
                  emails.append(settings.SAFE_EMAIL_RECIPIENT)
          return emails, email_modified
docs: Given a list of emails, checks whether they are all in the white
          list.