PHPMailer\PHPMailer\SMTP::parseHelloFields PHP Method

    protected function parseHelloFields($type)
    {
        $this->server_caps = [];
        $lines = explode("\n", $this->helo_rply);
        foreach ($lines as $n => $s) {
            //First 4 chars contain response code followed by - or space
            $s = trim(substr($s, 4));
            if (empty($s)) {
                continue;
            }
            $fields = explode(' ', $s);
            if (!empty($fields)) {
                if (!$n) {
                    $name = $type;
                    $fields = $fields[0];
                } else {
                    $name = array_shift($fields);
                    switch ($name) {
                        case 'SIZE':
                            $fields = $fields ? $fields[0] : 0;
                            break;
                        case 'AUTH':
                            if (!is_array($fields)) {
                                $fields = [];
                            }
                            break;
                        default:
                            $fields = true;
                    }
                }
                $this->server_caps[$name] = $fields;
            }
        }
    }