PHPMailer::smtpConnect( array $options = null ): bool

2144    public function smtpConnect($options = null)2145    {2146        if (null === $this->smtp) {2147            $this->smtp = $this->getSMTPInstance();2148        }2149 2150        //If no options are provided, use whatever is set in the instance2151        if (null === $options) {2152            $options = $this->SMTPOptions;2153        }2154 2155        //Already connected?2156        if ($this->smtp->connected()) {2157            return true;2158        }2159 2160        $this->smtp->setTimeout($this->Timeout);2161        $this->smtp->setDebugLevel($this->SMTPDebug);2162        $this->smtp->setDebugOutput($this->Debugoutput);2163        $this->smtp->setVerp($this->do_verp);2164        if ($this->Host === null) {2165            $this->Host = 'localhost';2166        }2167        $hosts = explode(';', $this->Host);2168        $lastexception = null;2169 2170        foreach ($hosts as $hostentry) {2171            $hostinfo = [];2172            if (2173                !preg_match(2174                    '/^(?:(ssl|tls):\/\/)?(.+?)(?::(\d+))?$/',2175                    trim($hostentry),2176                    $hostinfo2177                )2178            ) {2179                $this->edebug($this->lang('invalid_hostentry') . ' ' . trim($hostentry));2180                //Not a valid host entry2181                continue;2182            }2183            //$hostinfo[1]: optional ssl or tls prefix2184            //$hostinfo[2]: the hostname2185            //$hostinfo[3]: optional port number2186            //The host string prefix can temporarily override the current setting for SMTPSecure2187            //If it's not specified, the default value is used2188 2189            //Check the host name is a valid name or IP address before trying to use it2190            if (!static::isValidHost($hostinfo[2])) {2191                $this->edebug($this->lang('invalid_host') . ' ' . $hostinfo[2]);2192                continue;2193            }2194            $prefix = '';2195            $secure = $this->SMTPSecure;2196            $tls = (static::ENCRYPTION_STARTTLS === $this->SMTPSecure);2197            if ('ssl' === $hostinfo[1] || ('' === $hostinfo[1] && static::ENCRYPTION_SMTPS === $this->SMTPSecure)) {2198                $prefix = 'ssl://';2199                $tls = false; //Can't have SSL and TLS at the same time2200                $secure = static::ENCRYPTION_SMTPS;2201            } elseif ('tls' === $hostinfo[1]) {2202                $tls = true;2203                //TLS doesn't use a prefix2204                $secure = static::ENCRYPTION_STARTTLS;2205            }2206            //Do we need the OpenSSL extension?2207            $sslext = defined('OPENSSL_ALGO_SHA256');2208            if (static::ENCRYPTION_STARTTLS === $secure || static::ENCRYPTION_SMTPS === $secure) {2209                //Check for an OpenSSL constant rather than using extension_loaded, which is sometimes disabled2210                if (!$sslext) {2211                    throw new Exception($this->lang('extension_missing') . 'openssl', self::STOP_CRITICAL);2212                }2213            }2214            $host = $hostinfo[2];2215            $port = $this->Port;2216            if (2217                array_key_exists(3, $hostinfo) &&2218                is_numeric($hostinfo[3]) &&2219                $hostinfo[3] > 0 &&2220                $hostinfo[3] < 655362221            ) {2222                $port = (int) $hostinfo[3];2223            }