def smtpState_maybeAuthenticated(self, code, resp):
        """
        Called to handle the next message from the server after sending a
        response to a SASL challenge.  The server response might be another
        challenge or it might indicate authentication has succeeded.
        """
        if code == 235:
            # Yes, authenticated!
            del self._authinfo
            self.smtpState_from(code, resp)
        else:
            # No, not authenticated yet.  Keep trying.
            self._authResponse(self._authinfo, resp)

        Called to handle the next message from the server after sending a
        response to a SASL challenge.  The server response might be another
        challenge or it might indicate authentication has succeeded.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/smtp.py