<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def send(self, email=None):

 """ send email message """

        if email is None and self.send_as_one:
            self.smtp.send_message(
                self.multipart, self.config['EMAIL'], self.addresses)
        elif email is not None and self.send_as_one is False:
            self.smtp.send_message(
                self.multipart, self.config['EMAIL'], email)
        self.multipart = MIMEMultipart('alternative')