src/Mailer/SMTP.php
protected function connect()
    {
        $this->logger && $this->logger->debug("Connecting to {$this->host} at {$this->port}");
        $host = ($this->secure == 'ssl') ? 'ssl://' . $this->host : $this->host;
        $this->smtp = @fsockopen($host, $this->port);
        //set block mode
        //    stream_set_blocking($this->smtp, 1);
        if (!$this->smtp){
            throw new SMTPException("Could not open SMTP Port.");
        }
        $code = $this->getCode();
        if ($code !== '220'){
            throw new CodeException('220', $code, array_pop($this->resultStack));
        }
        return $this;
    }
protected function connect()
    {
        $this->logger && $this->logger->debug("Connecting to {$this->host} at {$this->port}");
        $host = ($this->secure == 'ssl') ? 'ssl://' . $this->host : $this->host;
        $this->smtp = @fsockopen($host, $this->port);
        //set block mode
        //    stream_set_blocking($this->smtp, 1);
        if (!$this->smtp){
            throw new SMTPException("Could not open SMTP Port.");
        }
        $code = $this->getCode();
        if ($code !== '220'){
            throw new CodeException('220', $code, array_pop($this->resultStack));
        }
        return $this;
    }
connect the server
SUCCESS 220
@return $this
@throws CodeException
@throws SMTPException