def smtp_DATA(self, arg):
        if not self.__rcpttos:
            self.push('503 Error: need RCPT command')
            return
        if arg:
            self.push('501 Syntax: DATA')
            return
        self.__state = self.DATA
        self.set_terminator('\r\n.\r\n')
        self.push('354 End data with <CR><LF>.<CR><LF>')