/**
* Protected method for sending data to SMTP connection
*
* @param string $data data to be sent to SMTP server
* @param string|bool $checkCode code to check for in server response, false to skip
* @return string|null The matched code, or null if nothing matched
* @throws \Cake\Network\Exception\SocketException
*/
protected function _smtpSend($data, $checkCode = '250')
{
$this->_lastResponse = [];
if ($data !== null) {
$this->_socket->write($data . "\r\n");
}
$timeout = $this->_config['timeout'];
while ($checkCode !== false) {
$response = '';
$startTime = time();
while (substr($response, -2) !== "\r\n" && time() - $startTime < $timeout) {
$response .= $this->_socket->read();
}
if (substr($response, -2) !== "\r\n") {
throw new SocketException('SMTP timeout.');
}
$responseLines = explode("\r\n", rtrim($response, "\r\n"));
$response = end($responseLines);
$this->_bufferResponseLines($responseLines);
if (preg_match('/^(' . $checkCode . ')(.)/', $response, $code)) {
if ($code[2] === '-') {
continue;
}
return $code[1];
}
throw new SocketException(sprintf('SMTP Error: %s', $response));
}
}
