def connectionMade(self):
        """
        Send a greeting to the client after the connection has been made.
        """
        if self.magic is None:
            self.magic = self.generateMagic()
        self.successResponse(self.magic)
        self.setTimeout(self.timeOut)
        if getattr(self.factory, 'noisy', True):
            log.msg("New connection from " + str(self.transport.getPeer()))

        Send a greeting to the client after the connection has been made.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/pop3.py