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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def rcptto(self, recipients):
 """ Send LMTP RCPT TO command, and process the server response. The DSPAM server expects to find one or more valid DSPAM users as envelope recipients. The set recipient will be the user DSPAM processes mail for. When you need want DSPAM to deliver the message itself, and need to pass the server an envelope recipient for this that differs from the DSPAM user account name, use the --rcpt-to parameter in client_args at mailfrom(). args: recipients -- A list of recipients """

        for rcpt in recipients:
            self._send('RCPT TO:<{}>\r\n'.format(rcpt))
            resp = self._read()
            if not resp.startswith('250'):
                raise DspamClientError(
                    'Unexpected server response at RCPT TO for '
                    'recipient {}: {}'.format(rcpt, resp))
            self._recipients.append(rcpt)