PHPMailer.php

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<?php
namespace PHPMailer\PHPMailer;
 
class PHPMailer
{
    const CHARSET_ASCII = 'us-ascii';
    const CHARSET_ISO88591 = 'iso-8859-1';
    const CHARSET_UTF8 = 'utf-8';
 
    const CONTENT_TYPE_PLAINTEXT = 'text/plain';
    const CONTENT_TYPE_TEXT_CALENDAR = 'text/calendar';
    const CONTENT_TYPE_TEXT_HTML = 'text/html';
    const CONTENT_TYPE_MULTIPART_ALTERNATIVE = 'multipart/alternative';
    const CONTENT_TYPE_MULTIPART_MIXED = 'multipart/mixed';
    const CONTENT_TYPE_MULTIPART_RELATED = 'multipart/related';
 
    const ENCODING_7BIT = '7bit';
    const ENCODING_8BIT = '8bit';
    const ENCODING_BASE64 = 'base64';
    const ENCODING_BINARY = 'binary';
    const ENCODING_QUOTED_PRINTABLE = 'quoted-printable';
 
    const ENCRYPTION_STARTTLS = 'tls';
    const ENCRYPTION_SMTPS = 'ssl';
 
    const ICAL_METHOD_REQUEST = 'REQUEST';
    const ICAL_METHOD_PUBLISH = 'PUBLISH';
    const ICAL_METHOD_REPLY = 'REPLY';
    const ICAL_METHOD_ADD = 'ADD';
    const ICAL_METHOD_CANCEL = 'CANCEL';
    const ICAL_METHOD_REFRESH = 'REFRESH';
    const ICAL_METHOD_COUNTER = 'COUNTER';
    const ICAL_METHOD_DECLINECOUNTER = 'DECLINECOUNTER';
 
    public $Priority;
 
    public $CharSet = self::CHARSET_ISO88591;
 
    public $ContentType = self::CONTENT_TYPE_PLAINTEXT;
 
    public $Encoding = self::ENCODING_8BIT;
 
    public $ErrorInfo = '';
 
    public $From = 'root@localhost';
 
    public $FromName = 'Root User';
 
    public $Sender = '';
 
    public $Subject = '';
 
    public $Body = '';
 
    public $AltBody = '';
 
    public $Ical = '';
 
    protected static $IcalMethods = [
        self::ICAL_METHOD_REQUEST,
        self::ICAL_METHOD_PUBLISH,
        self::ICAL_METHOD_REPLY,
        self::ICAL_METHOD_ADD,
        self::ICAL_METHOD_CANCEL,
        self::ICAL_METHOD_REFRESH,
        self::ICAL_METHOD_COUNTER,
        self::ICAL_METHOD_DECLINECOUNTER,
    ];
 
    protected $MIMEBody = '';
 
    protected $MIMEHeader = '';
 
    protected $mailHeader = '';
 
    public $WordWrap = 0;
 
    public $Mailer = 'mail';
 
    public $Sendmail = '/usr/sbin/sendmail';
 
    public $UseSendmailOptions = true;
 
    public $ConfirmReadingTo = '';
 
    public $Hostname = '';
 
    public $MessageID = '';
 
    public $MessageDate = '';
 
    public $Host = 'localhost';
 
    public $Port = 25;
 
    public $Helo = '';
 
    public $SMTPSecure = '';
 
    public $SMTPAutoTLS = true;
 
    public $SMTPAuth = false;
 
    public $SMTPOptions = [];
 
    public $Username = '';
 
    public $Password = '';
 
    public $AuthType = '';
 
    protected $oauth;
 
    public $Timeout = 300;
 
    public $dsn = '';
 
    public $SMTPDebug = 0;
 
    public $Debugoutput = 'echo';
 
    public $SMTPKeepAlive = false;
 
    public $SingleTo = false;
 
    protected $SingleToArray = [];
 
    public $do_verp = false;
 
    public $AllowEmpty = false;
 
    public $DKIM_selector = '';
 
    public $DKIM_identity = '';
 
    public $DKIM_passphrase = '';
 
    public $DKIM_domain = '';
 
    public $DKIM_copyHeaderFields = true;
 
    public $DKIM_extraHeaders = [];
 
    public $DKIM_private = '';
 
    public $DKIM_private_string = '';
 
    public $action_function = '';
 
    public $XMailer = '';
 
    public static $validator = 'php';
 
    protected $smtp;
 
    protected $to = [];
 
    protected $cc = [];
 
    protected $bcc = [];
 
    protected $ReplyTo = [];
 
    protected $all_recipients = [];
 
    protected $RecipientsQueue = [];
 
    protected $ReplyToQueue = [];
 
    protected $attachment = [];
 
    protected $CustomHeader = [];
 
    protected $lastMessageID = '';
 
    protected $message_type = '';
 
    protected $boundary = [];
 
    protected $language = [];
 
    protected $error_count = 0;
 
    protected $sign_cert_file = '';
 
    protected $sign_key_file = '';
 
    protected $sign_extracerts_file = '';
 
    protected $sign_key_pass = '';
 
    protected $exceptions = false;
 
    protected $uniqueid = '';
 
    const VERSION = '6.1.6';
 
    const STOP_MESSAGE = 0;
 
    const STOP_CONTINUE = 1;
 
    const STOP_CRITICAL = 2;
 
    const CRLF = "\r\n";
 
    const FWS = ' ';
 
    protected static $LE = self::CRLF;
 
    const MAIL_MAX_LINE_LENGTH = 63;
 
    const MAX_LINE_LENGTH = 998;
 
    const STD_LINE_LENGTH = 76;
 
    public function __construct($exceptions = null)
    {
        if (null !== $exceptions) {
            $this->exceptions = (bool) $exceptions;
        }
        //Pick an appropriate debug output format automatically
        $this->Debugoutput = (strpos(PHP_SAPI, 'cli') !== false ? 'echo' : 'html');
    }
 
    public function __destruct()
    {
        //Close any open SMTP connection nicely
        $this->smtpClose();
    }
 
    private function mailPassthru($to, $subject, $body, $header, $params)
    {
        //Check overloading of mail function to avoid double-encoding
        if (ini_get('mbstring.func_overload') & 1) {
            $subject = $this->secureHeader($subject);
        } else {
            $subject = $this->encodeHeader($this->secureHeader($subject));
        }
                // patch-mjansen: begin #20376
                if (0 == strlen($to) && strpos($header, 'To: undisclosed-recipients:;') !== false) {
                        $to     = 'undisclosed-recipients:;';
                        $header = preg_replace('/To: undisclosed-recipients:;(\s*)/', '', $header);
                }
                // patch-mjansen: end
        //Calling mail() with null params breaks
        if (!$this->UseSendmailOptions || null === $params) {
            $result = @mail($to, $subject, $body, $header);
        } else {
            $result = @mail($to, $subject, $body, $header, $params);
        }
 
        return $result;
    }
 
    protected function edebug($str)
    {
        if ($this->SMTPDebug <= 0) {
            return;
        }
        //Is this a PSR-3 logger?
        if ($this->Debugoutput instanceof \Psr\Log\LoggerInterface) {
            $this->Debugoutput->debug($str);
 
            return;
        }
        //Avoid clash with built-in function names
        if (is_callable($this->Debugoutput) && !in_array($this->Debugoutput, ['error_log', 'html', 'echo'])) {
            call_user_func($this->Debugoutput, $str, $this->SMTPDebug);
 
            return;
        }
        switch ($this->Debugoutput) {
            case 'error_log':
                //Don't output, just log
                error_log($str);
                break;
            case 'html':
                //Cleans up output a bit for a better looking, HTML-safe output
                echo htmlentities(
                    preg_replace('/[\r\n]+/', '', $str),
                    ENT_QUOTES,
                    'UTF-8'
                ), "<br>\n";
                break;
            case 'echo':
            default:
                //Normalize line breaks
                $str = preg_replace('/\r\n|\r/m', "\n", $str);
                echo gmdate('Y-m-d H:i:s'),
                "\t",
                    //Trim trailing space
                trim(
                    //Indent for readability, except for trailing break
                    str_replace(
                        "\n",
                        "\n                   \t                  ",
                        trim($str)
                    )
                ),
                "\n";
        }
    }
 
    public function isHTML($isHtml = true)
    {
        if ($isHtml) {
            $this->ContentType = static::CONTENT_TYPE_TEXT_HTML;
        } else {
            $this->ContentType = static::CONTENT_TYPE_PLAINTEXT;
        }
    }
 
    public function isSMTP()
    {
        $this->Mailer = 'smtp';
    }
 
    public function isMail()
    {
        $this->Mailer = 'mail';
    }
 
    public function isSendmail()
    {
        $ini_sendmail_path = ini_get('sendmail_path');
 
        if (false === stripos($ini_sendmail_path, 'sendmail')) {
            $this->Sendmail = '/usr/sbin/sendmail';
        } else {
            $this->Sendmail = $ini_sendmail_path;
        }
        $this->Mailer = 'sendmail';
    }
 
    public function isQmail()
    {
        $ini_sendmail_path = ini_get('sendmail_path');
 
        if (false === stripos($ini_sendmail_path, 'qmail')) {
            $this->Sendmail = '/var/qmail/bin/qmail-inject';
        } else {
            $this->Sendmail = $ini_sendmail_path;
        }
        $this->Mailer = 'qmail';
    }
 
    public function addAddress($address, $name = '')
    {
        return $this->addOrEnqueueAnAddress('to', $address, $name);
    }
 
    public function addCC($address, $name = '')
    {
        return $this->addOrEnqueueAnAddress('cc', $address, $name);
    }
 
    public function addBCC($address, $name = '')
    {
        return $this->addOrEnqueueAnAddress('bcc', $address, $name);
    }
 
    public function addReplyTo($address, $name = '')
    {
        return $this->addOrEnqueueAnAddress('Reply-To', $address, $name);
    }
 
    protected function addOrEnqueueAnAddress($kind, $address, $name)
    {
        $address = trim($address);
        $name = trim(preg_replace('/[\r\n]+/', '', $name)); //Strip breaks and trim
        $pos = strrpos($address, '@');
        if (false === $pos) {
            // At-sign is missing.
            $error_message = sprintf(
                '%s (%s): %s',
                $this->lang('invalid_address'),
                $kind,
                $address
            );
            $this->setError($error_message);
            $this->edebug($error_message);
            if ($this->exceptions) {
                throw new Exception($error_message);
            }
 
            return false;
        }
        $params = [$kind, $address, $name];
        // Enqueue addresses with IDN until we know the PHPMailer::$CharSet.
        if (static::idnSupported() && $this->has8bitChars(substr($address, ++$pos))) {
            if ('Reply-To' !== $kind) {
                if (!array_key_exists($address, $this->RecipientsQueue)) {
                    $this->RecipientsQueue[$address] = $params;
 
                    return true;
                }
            } elseif (!array_key_exists($address, $this->ReplyToQueue)) {
                $this->ReplyToQueue[$address] = $params;
 
                return true;
            }
 
            return false;
        }
 
        // Immediately add standard addresses without IDN.
        return call_user_func_array([$this, 'addAnAddress'], $params);
    }
 
    protected function addAnAddress($kind, $address, $name = '')
    {
        if (!in_array($kind, ['to', 'cc', 'bcc', 'Reply-To'])) {
            $error_message = sprintf(
                '%s: %s',
                $this->lang('Invalid recipient kind'),
                $kind
            );
            $this->setError($error_message);
            $this->edebug($error_message);
            if ($this->exceptions) {
                throw new Exception($error_message);
            }
 
            return false;
        }
        if (!static::validateAddress($address)) {
            $error_message = sprintf(
                '%s (%s): %s',
                $this->lang('invalid_address'),
                $kind,
                $address
            );
            $this->setError($error_message);
            $this->edebug($error_message);
            if ($this->exceptions) {
                throw new Exception($error_message);
            }
 
            return false;
        }
        if ('Reply-To' !== $kind) {
            if (!array_key_exists(strtolower($address), $this->all_recipients)) {
                $this->{$kind}[] = [$address, $name];
                $this->all_recipients[strtolower($address)] = true;
 
                return true;
            }
        } elseif (!array_key_exists(strtolower($address), $this->ReplyTo)) {
            $this->ReplyTo[strtolower($address)] = [$address, $name];
 
            return true;
        }
 
        return false;
    }
 
    public static function parseAddresses($addrstr, $useimap = true)
    {
        $addresses = [];
        if ($useimap && function_exists('imap_rfc822_parse_adrlist')) {
            //Use this built-in parser if it's available
            $list = imap_rfc822_parse_adrlist($addrstr, '');
            foreach ($list as $address) {
                if (('.SYNTAX-ERROR.' !== $address->host) && static::validateAddress(
                    $address->mailbox . '@' . $address->host
                )) {
                    $addresses[] = [
                        'name' => (property_exists($address, 'personal') ? $address->personal : ''),
                        'address' => $address->mailbox . '@' . $address->host,
                    ];
                }
            }
        } else {
            //Use this simpler parser
            $list = explode(',', $addrstr);
            foreach ($list as $address) {
                $address = trim($address);
                //Is there a separate name part?
                if (strpos($address, '<') === false) {
                    //No separate name, just use the whole thing
                    if (static::validateAddress($address)) {
                        $addresses[] = [
                            'name' => '',
                            'address' => $address,
                        ];
                    }
                } else {
                    list($name, $email) = explode('<', $address);
                    $email = trim(str_replace('>', '', $email));
                    if (static::validateAddress($email)) {
                        $addresses[] = [
                            'name' => trim(str_replace(['"', "'"], '', $name)),
                            'address' => $email,
                        ];
                    }
                }
            }
        }
 
        return $addresses;
    }
 
    public function setFrom($address, $name = '', $auto = true)
    {
        $address = trim($address);
        $name = trim(preg_replace('/[\r\n]+/', '', $name)); //Strip breaks and trim
        // Don't validate now addresses with IDN. Will be done in send().
        $pos = strrpos($address, '@');
        if ((false === $pos)
            || ((!$this->has8bitChars(substr($address, ++$pos)) || !static::idnSupported())
            && !static::validateAddress($address))
        ) {
            $error_message = sprintf(
                '%s (From): %s',
                $this->lang('invalid_address'),
                $address
            );
            $this->setError($error_message);
            $this->edebug($error_message);
            if ($this->exceptions) {
                throw new Exception($error_message);
            }
 
            return false;
        }
        $this->From = $address;
        $this->FromName = $name;
        if ($auto && empty($this->Sender)) {
            $this->Sender = $address;
        }
 
        return true;
    }
 
    public function getLastMessageID()
    {
        return $this->lastMessageID;
    }
 
    public static function validateAddress($address, $patternselect = null)
    {
        if (null === $patternselect) {
            $patternselect = static::$validator;
        }
        if (is_callable($patternselect)) {
            return $patternselect($address);
        }
        //Reject line breaks in addresses; it's valid RFC5322, but not RFC5321
        if (strpos($address, "\n") !== false || strpos($address, "\r") !== false) {
            return false;
        }
        switch ($patternselect) {
            case 'pcre': //Kept for BC
            case 'pcre8':
                /*
                 * A more complex and more permissive version of the RFC5322 regex on which FILTER_VALIDATE_EMAIL
                 * is based.
                 * In addition to the addresses allowed by filter_var, also permits:
                 *  * dotless domains: `a@b`
                 *  * comments: `1234 @ local(blah) .machine .example`
                 *  * quoted elements: `'"test blah"@example.org'`
                 *  * numeric TLDs: `a@b.123`
                 *  * unbracketed IPv4 literals: `a@192.168.0.1`
                 *  * IPv6 literals: 'first.last@[IPv6:a1::]'
                 * Not all of these will necessarily work for sending!
                 *
                 * @see       http://squiloople.com/2009/12/20/email-address-validation/
                 * @copyright 2009-2010 Michael Rushton
                 * Feel free to use and redistribute this code. But please keep this copyright notice.
                 */
                return (bool) preg_match(
                    '/^(?!(?>(?1)"?(?>\\\[ -~]|[^"])"?(?1)){255,})(?!(?>(?1)"?(?>\\\[ -~]|[^"])"?(?1)){65,}@)' .
                    '((?>(?>(?>((?>(?>(?>\x0D\x0A)?[\t ])+|(?>[\t ]*\x0D\x0A)?[\t ]+)?)(\‍((?>(?2)' .
                    '(?>[\x01-\x08\x0B\x0C\x0E-\'*-\[\]-\x7F]|\\\[\x00-\x7F]|(?3)))*(?2)\‍)))+(?2))|(?2))?)' .
                    '([!#-\'*+\/-9=?^-~-]+|"(?>(?2)(?>[\x01-\x08\x0B\x0C\x0E-!#-\[\]-\x7F]|\\\[\x00-\x7F]))*' .
                    '(?2)")(?>(?1)\.(?1)(?4))*(?1)@(?!(?1)[a-z0-9-]{64,})(?1)(?>([a-z0-9](?>[a-z0-9-]*[a-z0-9])?)' .
                    '(?>(?1)\.(?!(?1)[a-z0-9-]{64,})(?1)(?5)){0,126}|\[(?:(?>IPv6:(?>([a-f0-9]{1,4})(?>:(?6)){7}' .
                    '|(?!(?:.*[a-f0-9][:\]]){8,})((?6)(?>:(?6)){0,6})?::(?7)?))|(?>(?>IPv6:(?>(?6)(?>:(?6)){5}:' .
                    '|(?!(?:.*[a-f0-9]:){6,})(?8)?::(?>((?6)(?>:(?6)){0,4}):)?))?(25[0-5]|2[0-4][0-9]|1[0-9]{2}' .
                    '|[1-9]?[0-9])(?>\.(?9)){3}))\])(?1)$/isD',
                    $address
                );
            case 'html5':
                /*
                 * This is the pattern used in the HTML5 spec for validation of 'email' type form input elements.
                 *
                 * @see http://www.whatwg.org/specs/web-apps/current-work/#e-mail-state-(type=email)
                 */
                return (bool) preg_match(
                    '/^[a-zA-Z0-9.!#$%&\'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}' .
                    '[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/sD',
                    $address
                );
            case 'php':
            default:
                return filter_var($address, FILTER_VALIDATE_EMAIL) !== false;
        }
    }
 
    public static function idnSupported()
    {
        return function_exists('idn_to_ascii') && function_exists('mb_convert_encoding');
    }
 
    public function punyencodeAddress($address)
    {
        // Verify we have required functions, CharSet, and at-sign.
        $pos = strrpos($address, '@');
        if (!empty($this->CharSet) &&
            false !== $pos &&
            static::idnSupported()
        ) {
            $domain = substr($address, ++$pos);
            // Verify CharSet string is a valid one, and domain properly encoded in this CharSet.
            if ($this->has8bitChars($domain) && @mb_check_encoding($domain, $this->CharSet)) {
                $domain = mb_convert_encoding($domain, 'UTF-8', $this->CharSet);
                //Ignore IDE complaints about this line - method signature changed in PHP 5.4
                $errorcode = 0;
                if (defined('INTL_IDNA_VARIANT_UTS46')) {
                    $punycode = idn_to_ascii($domain, $errorcode, INTL_IDNA_VARIANT_UTS46);
                } elseif (defined('INTL_IDNA_VARIANT_2003')) {
                    $punycode = idn_to_ascii($domain, $errorcode, INTL_IDNA_VARIANT_2003);
                } else {
                    $punycode = idn_to_ascii($domain, $errorcode);
                }
                if (false !== $punycode) {
                    return substr($address, 0, $pos) . $punycode;
                }
            }
        }
 
        return $address;
    }
 
    public function send()
    {
        try {
            if (!$this->preSend()) {
                return false;
            }
 
            return $this->postSend();
        } catch (Exception $exc) {
            $this->mailHeader = '';
            $this->setError($exc->getMessage());
            if ($this->exceptions) {
                throw $exc;
            }
 
            return false;
        }
    }
 
    public function preSend()
    {
        if ('smtp' === $this->Mailer
            || ('mail' === $this->Mailer && stripos(PHP_OS, 'WIN') === 0)
        ) {
            //SMTP mandates RFC-compliant line endings
            //and it's also used with mail() on Windows
            static::setLE(self::CRLF);
        } else {
            //Maintain backward compatibility with legacy Linux command line mailers
            static::setLE(PHP_EOL);
        }
        //Check for buggy PHP versions that add a header with an incorrect line break
        if ('mail' === $this->Mailer
            && ((PHP_VERSION_ID >= 70000 && PHP_VERSION_ID < 70017)
                || (PHP_VERSION_ID >= 70100 && PHP_VERSION_ID < 70103))
            && ini_get('mail.add_x_header') === '1'
            && stripos(PHP_OS, 'WIN') === 0
        ) {
            trigger_error(
                'Your version of PHP is affected by a bug that may result in corrupted messages.' .
                ' To fix it, switch to sending using SMTP, disable the mail.add_x_header option in' .
                ' your php.ini, switch to MacOS or Linux, or upgrade your PHP to version 7.0.17+ or 7.1.3+.',
                E_USER_WARNING
            );
        }
 
        try {
            $this->error_count = 0; // Reset errors
            $this->mailHeader = '';
 
            // Dequeue recipient and Reply-To addresses with IDN
            foreach (array_merge($this->RecipientsQueue, $this->ReplyToQueue) as $params) {
                $params[1] = $this->punyencodeAddress($params[1]);
                call_user_func_array([$this, 'addAnAddress'], $params);
            }
            if (count($this->to) + count($this->cc) + count($this->bcc) < 1) {
                throw new Exception($this->lang('provide_address'), self::STOP_CRITICAL);
            }
 
            // Validate From, Sender, and ConfirmReadingTo addresses
            foreach (['From', 'Sender', 'ConfirmReadingTo'] as $address_kind) {
                $this->$address_kind = trim($this->$address_kind);
                if (empty($this->$address_kind)) {
                    continue;
                }
                $this->$address_kind = $this->punyencodeAddress($this->$address_kind);
                if (!static::validateAddress($this->$address_kind)) {
                    $error_message = sprintf(
                        '%s (%s): %s',
                        $this->lang('invalid_address'),
                        $address_kind,
                        $this->$address_kind
                    );
                    $this->setError($error_message);
                    $this->edebug($error_message);
                    if ($this->exceptions) {
                        throw new Exception($error_message);
                    }
 
                    return false;
                }
            }
 
            // Set whether the message is multipart/alternative
            if ($this->alternativeExists()) {
                $this->ContentType = static::CONTENT_TYPE_MULTIPART_ALTERNATIVE;
            }
 
            $this->setMessageType();
            // Refuse to send an empty message unless we are specifically allowing it
            if (!$this->AllowEmpty && empty($this->Body)) {
                throw new Exception($this->lang('empty_message'), self::STOP_CRITICAL);
            }
 
            //Trim subject consistently
            $this->Subject = trim($this->Subject);
            // Create body before headers in case body makes changes to headers (e.g. altering transfer encoding)
            $this->MIMEHeader = '';
            $this->MIMEBody = $this->createBody();
            // createBody may have added some headers, so retain them
            $tempheaders = $this->MIMEHeader;
            $this->MIMEHeader = $this->createHeader();
            $this->MIMEHeader .= $tempheaders;
 
            // To capture the complete message when using mail(), create
            // an extra header list which createHeader() doesn't fold in
            if ('mail' === $this->Mailer) {
                if (count($this->to) > 0) {
                    $this->mailHeader .= $this->addrAppend('To', $this->to);
                } else {
                    $this->mailHeader .= $this->headerLine('To', 'undisclosed-recipients:;');
                }
                $this->mailHeader .= $this->headerLine(
                    'Subject',
                    $this->encodeHeader($this->secureHeader($this->Subject))
                );
            }
 
            // Sign with DKIM if enabled
            if (!empty($this->DKIM_domain)
                && !empty($this->DKIM_selector)
                && (!empty($this->DKIM_private_string)
                    || (!empty($this->DKIM_private)
                        && static::isPermittedPath($this->DKIM_private)
                        && file_exists($this->DKIM_private)
                    )
                )
            ) {
                $header_dkim = $this->DKIM_Add(
                    $this->MIMEHeader . $this->mailHeader,
                    $this->encodeHeader($this->secureHeader($this->Subject)),
                    $this->MIMEBody
                );
                $this->MIMEHeader = static::stripTrailingWSP($this->MIMEHeader) . static::$LE .
                    static::normalizeBreaks($header_dkim) . static::$LE;
            }
 
            return true;
        } catch (Exception $exc) {
            $this->setError($exc->getMessage());
            if ($this->exceptions) {
                throw $exc;
            }
 
            return false;
        }
    }
 
    public function postSend()
    {
        try {
            // Choose the mailer and send through it
            switch ($this->Mailer) {
                case 'sendmail':
                case 'qmail':
                    return $this->sendmailSend($this->MIMEHeader, $this->MIMEBody);
                case 'smtp':
                    return $this->smtpSend($this->MIMEHeader, $this->MIMEBody);
                case 'mail':
                    return $this->mailSend($this->MIMEHeader, $this->MIMEBody);
                default:
                    $sendMethod = $this->Mailer . 'Send';
                    if (method_exists($this, $sendMethod)) {
                        return $this->$sendMethod($this->MIMEHeader, $this->MIMEBody);
                    }
 
                    return $this->mailSend($this->MIMEHeader, $this->MIMEBody);
            }
        } catch (Exception $exc) {
            $this->setError($exc->getMessage());
            $this->edebug($exc->getMessage());
            if ($this->exceptions) {
                throw $exc;
            }
        }
 
        return false;
    }
 
    protected function sendmailSend($header, $body)
    {
        $header = static::stripTrailingWSP($header) . static::$LE . static::$LE;
 
        // CVE-2016-10033, CVE-2016-10045: Don't pass -f if characters will be escaped.
        if (!empty($this->Sender) && self::isShellSafe($this->Sender)) {
            if ('qmail' === $this->Mailer) {
                $sendmailFmt = '%s -f%s';
            } else {
                $sendmailFmt = '%s -oi -f%s -t';
            }
        } elseif ('qmail' === $this->Mailer) {
            $sendmailFmt = '%s';
        } else {
            $sendmailFmt = '%s -oi -t';
        }
 
        $sendmail = sprintf($sendmailFmt, escapeshellcmd($this->Sendmail), $this->Sender);
 
        if ($this->SingleTo) {
            foreach ($this->SingleToArray as $toAddr) {
                $mail = @popen($sendmail, 'w');
                if (!$mail) {
                    throw new Exception($this->lang('execute') . $this->Sendmail, self::STOP_CRITICAL);
                }
                fwrite($mail, 'To: ' . $toAddr . "\n");
                fwrite($mail, $header);
                fwrite($mail, $body);
                $result = pclose($mail);
                $this->doCallback(
                    ($result === 0),
                    [$toAddr],
                    $this->cc,
                    $this->bcc,
                    $this->Subject,
                    $body,
                    $this->From,
                    []
                );
                if (0 !== $result) {
                    throw new Exception($this->lang('execute') . $this->Sendmail, self::STOP_CRITICAL);
                }
            }
        } else {
            $mail = @popen($sendmail, 'w');
            if (!$mail) {
                throw new Exception($this->lang('execute') . $this->Sendmail, self::STOP_CRITICAL);
            }
            fwrite($mail, $header);
            fwrite($mail, $body);
            $result = pclose($mail);
            $this->doCallback(
                ($result === 0),
                $this->to,
                $this->cc,
                $this->bcc,
                $this->Subject,
                $body,
                $this->From,
                []
            );
            if (0 !== $result) {
                throw new Exception($this->lang('execute') . $this->Sendmail, self::STOP_CRITICAL);
            }
        }
 
        return true;
    }
 
    protected static function isShellSafe($string)
    {
        // Future-proof
        if (escapeshellcmd($string) !== $string
            || !in_array(escapeshellarg($string), ["'$string'", "\"$string\""])
        ) {
            return false;
        }
 
        $length = strlen($string);
 
        for ($i = 0; $i < $length; ++$i) {
            $c = $string[$i];
 
            // All other characters have a special meaning in at least one common shell, including = and +.
            // Full stop (.) has a special meaning in cmd.exe, but its impact should be negligible here.
            // Note that this does permit non-Latin alphanumeric characters based on the current locale.
            if (!ctype_alnum($c) && strpos('@_-.', $c) === false) {
                return false;
            }
        }
 
        return true;
    }
 
    protected static function isPermittedPath($path)
    {
        return !preg_match('#^[a-z]+://#i', $path);
    }
 
    protected function mailSend($header, $body)
    {
        $header = static::stripTrailingWSP($header) . static::$LE . static::$LE;
 
        $toArr = [];
        foreach ($this->to as $toaddr) {
            $toArr[] = $this->addrFormat($toaddr);
        }
        $to = implode(', ', $toArr);
 
        $params = null;
        //This sets the SMTP envelope sender which gets turned into a return-path header by the receiver
        //A space after `-f` is optional, but there is a long history of its presence
        //causing problems, so we don't use one
        //Exim docs: http://www.exim.org/exim-html-current/doc/html/spec_html/ch-the_exim_command_line.html
        //Sendmail docs: http://www.sendmail.org/~ca/email/man/sendmail.html
        //Qmail docs: http://www.qmail.org/man/man8/qmail-inject.html
        //Example problem: https://www.drupal.org/node/1057954
        // CVE-2016-10033, CVE-2016-10045: Don't pass -f if characters will be escaped.
        if (!empty($this->Sender) && static::validateAddress($this->Sender) && self::isShellSafe($this->Sender)) {
            $params = sprintf('-f%s', $this->Sender);
        }
        if (!empty($this->Sender) && static::validateAddress($this->Sender)) {
            $old_from = ini_get('sendmail_from');
            ini_set('sendmail_from', $this->Sender);
        }
        $result = false;
        if ($this->SingleTo && count($toArr) > 1) {
            foreach ($toArr as $toAddr) {
                $result = $this->mailPassthru($toAddr, $this->Subject, $body, $header, $params);
                $this->doCallback($result, [$toAddr], $this->cc, $this->bcc, $this->Subject, $body, $this->From, []);
            }
        } else {
            $result = $this->mailPassthru($to, $this->Subject, $body, $header, $params);
            $this->doCallback($result, $this->to, $this->cc, $this->bcc, $this->Subject, $body, $this->From, []);
        }
        if (isset($old_from)) {
            ini_set('sendmail_from', $old_from);
        }
        if (!$result) {
            throw new Exception($this->lang('instantiate'), self::STOP_CRITICAL);
        }
 
        return true;
    }
 
    public function getSMTPInstance()
    {
        if (!is_object($this->smtp)) {
            $this->smtp = new SMTP();
        }
 
        return $this->smtp;
    }
 
    public function setSMTPInstance(SMTP $smtp)
    {
        $this->smtp = $smtp;
 
        return $this->smtp;
    }
 
    protected function smtpSend($header, $body)
    {
        $header = static::stripTrailingWSP($header) . static::$LE . static::$LE;
        $bad_rcpt = [];
        if (!$this->smtpConnect($this->SMTPOptions)) {
            throw new Exception($this->lang('smtp_connect_failed'), self::STOP_CRITICAL);
        }
        //Sender already validated in preSend()
        if ('' === $this->Sender) {
            $smtp_from = $this->From;
        } else {
            $smtp_from = $this->Sender;
        }
        if (!$this->smtp->mail($smtp_from)) {
            $this->setError($this->lang('from_failed') . $smtp_from . ' : ' . implode(',', $this->smtp->getError()));
            throw new Exception($this->ErrorInfo, self::STOP_CRITICAL);
        }
 
        $callbacks = [];
        // Attempt to send to all recipients
        foreach ([$this->to, $this->cc, $this->bcc] as $togroup) {
            foreach ($togroup as $to) {
                if (!$this->smtp->recipient($to[0], $this->dsn)) {
                    $error = $this->smtp->getError();
                    $bad_rcpt[] = ['to' => $to[0], 'error' => $error['detail']];
                    $isSent = false;
                } else {
                    $isSent = true;
                }
 
                $callbacks[] = ['issent'=>$isSent, 'to'=>$to[0]];
            }
        }
 
        // Only send the DATA command if we have viable recipients
        if ((count($this->all_recipients) > count($bad_rcpt)) && !$this->smtp->data($header . $body)) {
            throw new Exception($this->lang('data_not_accepted'), self::STOP_CRITICAL);
        }
 
        $smtp_transaction_id = $this->smtp->getLastTransactionID();
 
        if ($this->SMTPKeepAlive) {
            $this->smtp->reset();
        } else {
            $this->smtp->quit();
            $this->smtp->close();
        }
 
        foreach ($callbacks as $cb) {
            $this->doCallback(
                $cb['issent'],
                [$cb['to']],
                [],
                [],
                $this->Subject,
                $body,
                $this->From,
                ['smtp_transaction_id' => $smtp_transaction_id]
            );
        }
 
        //Create error message for any bad addresses
        if (count($bad_rcpt) > 0) {
            $errstr = '';
            foreach ($bad_rcpt as $bad) {
                $errstr .= $bad['to'] . ': ' . $bad['error'];
            }
            throw new Exception($this->lang('recipients_failed') . $errstr, self::STOP_CONTINUE);
        }
 
        return true;
    }
 
    public function smtpConnect($options = null)
    {
        if (null === $this->smtp) {
            $this->smtp = $this->getSMTPInstance();
        }
 
        //If no options are provided, use whatever is set in the instance
        if (null === $options) {
            $options = $this->SMTPOptions;
        }
 
        // Already connected?
        if ($this->smtp->connected()) {
            return true;
        }
 
        $this->smtp->setTimeout($this->Timeout);
        $this->smtp->setDebugLevel($this->SMTPDebug);
        $this->smtp->setDebugOutput($this->Debugoutput);
        $this->smtp->setVerp($this->do_verp);
        $hosts = explode(';', $this->Host);
        $lastexception = null;
 
        foreach ($hosts as $hostentry) {
            $hostinfo = [];
            if (!preg_match(
                '/^(?:(ssl|tls):\/\/)?(.+?)(?::(\d+))?$/',
                trim($hostentry),
                $hostinfo
            )) {
                $this->edebug($this->lang('invalid_hostentry') . ' ' . trim($hostentry));
                // Not a valid host entry
                continue;
            }
            // $hostinfo[1]: optional ssl or tls prefix
            // $hostinfo[2]: the hostname
            // $hostinfo[3]: optional port number
            // The host string prefix can temporarily override the current setting for SMTPSecure
            // If it's not specified, the default value is used
 
            //Check the host name is a valid name or IP address before trying to use it
            if (!static::isValidHost($hostinfo[2])) {
                $this->edebug($this->lang('invalid_host') . ' ' . $hostinfo[2]);
                continue;
            }
            $prefix = '';
            $secure = $this->SMTPSecure;
            $tls = (static::ENCRYPTION_STARTTLS === $this->SMTPSecure);
            if ('ssl' === $hostinfo[1] || ('' === $hostinfo[1] && static::ENCRYPTION_SMTPS === $this->SMTPSecure)) {
                $prefix = 'ssl://';
                $tls = false; // Can't have SSL and TLS at the same time
                $secure = static::ENCRYPTION_SMTPS;
            } elseif ('tls' === $hostinfo[1]) {
                $tls = true;
                // tls doesn't use a prefix
                $secure = static::ENCRYPTION_STARTTLS;
            }
            //Do we need the OpenSSL extension?
            $sslext = defined('OPENSSL_ALGO_SHA256');
            if (static::ENCRYPTION_STARTTLS === $secure || static::ENCRYPTION_SMTPS === $secure) {
                //Check for an OpenSSL constant rather than using extension_loaded, which is sometimes disabled
                if (!$sslext) {
                    throw new Exception($this->lang('extension_missing') . 'openssl', self::STOP_CRITICAL);
                }
            }
            $host = $hostinfo[2];
            $port = $this->Port;
            if (array_key_exists(3, $hostinfo) && is_numeric($hostinfo[3]) && $hostinfo[3] > 0 && $hostinfo[3] < 65536) {
                $port = (int) $hostinfo[3];
            }
            if ($this->smtp->connect($prefix . $host, $port, $this->Timeout, $options)) {
                try {
                    if ($this->Helo) {
                        $hello = $this->Helo;
                    } else {
                        $hello = $this->serverHostname();
                    }
                    $this->smtp->hello($hello);
                    //Automatically enable TLS encryption if:
                    // * it's not disabled
                    // * we have openssl extension
                    // * we are not already using SSL
                    // * the server offers STARTTLS
                    if ($this->SMTPAutoTLS && $sslext && 'ssl' !== $secure && $this->smtp->getServerExt('STARTTLS')) {
                        $tls = true;
                    }
                    if ($tls) {
                        if (!$this->smtp->startTLS()) {
                            throw new Exception($this->lang('connect_host'));
                        }
                        // We must resend EHLO after TLS negotiation
                        $this->smtp->hello($hello);
                    }
                    if ($this->SMTPAuth && !$this->smtp->authenticate(
                        $this->Username,
                        $this->Password,
                        $this->AuthType,
                        $this->oauth
                    )) {
                        throw new Exception($this->lang('authenticate'));
                    }
 
                    return true;
                } catch (Exception $exc) {
                    $lastexception = $exc;
                    $this->edebug($exc->getMessage());
                    // We must have connected, but then failed TLS or Auth, so close connection nicely
                    $this->smtp->quit();
                }
            }
        }
        // If we get here, all connection attempts have failed, so close connection hard
        $this->smtp->close();
        // As we've caught all exceptions, just report whatever the last one was
        if ($this->exceptions && null !== $lastexception) {
            throw $lastexception;
        }
 
        return false;
    }
 
    public function smtpClose()
    {
        if ((null !== $this->smtp) && $this->smtp->connected()) {
            $this->smtp->quit();
            $this->smtp->close();
        }
    }
 
    public function setLanguage($langcode = 'en', $lang_path = '')
    {
        // Backwards compatibility for renamed language codes
        $renamed_langcodes = [
            'br' => 'pt_br',
            'cz' => 'cs',
            'dk' => 'da',
            'no' => 'nb',
            'se' => 'sv',
            'rs' => 'sr',
            'tg' => 'tl',
            'am' => 'hy',
        ];
 
        if (isset($renamed_langcodes[$langcode])) {
            $langcode = $renamed_langcodes[$langcode];
        }
 
        // Define full set of translatable strings in English
        $PHPMAILER_LANG = [
            'authenticate' => 'SMTP Error: Could not authenticate.',
            'connect_host' => 'SMTP Error: Could not connect to SMTP host.',
            'data_not_accepted' => 'SMTP Error: data not accepted.',
            'empty_message' => 'Message body empty',
            'encoding' => 'Unknown encoding: ',
            'execute' => 'Could not execute: ',
            'file_access' => 'Could not access file: ',
            'file_open' => 'File Error: Could not open file: ',
            'from_failed' => 'The following From address failed: ',
            'instantiate' => 'Could not instantiate mail function.',
            'invalid_address' => 'Invalid address: ',
            'invalid_hostentry' => 'Invalid hostentry: ',
            'invalid_host' => 'Invalid host: ',
            'mailer_not_supported' => ' mailer is not supported.',
            'provide_address' => 'You must provide at least one recipient email address.',
            'recipients_failed' => 'SMTP Error: The following recipients failed: ',
            'signing' => 'Signing Error: ',
            'smtp_connect_failed' => 'SMTP connect() failed.',
            'smtp_error' => 'SMTP server error: ',
            'variable_set' => 'Cannot set or reset variable: ',
            'extension_missing' => 'Extension missing: ',
        ];
        if (empty($lang_path)) {
            // Calculate an absolute path so it can work if CWD is not here
            $lang_path = dirname(__DIR__) . DIRECTORY_SEPARATOR . 'language' . DIRECTORY_SEPARATOR;
        }
        //Validate $langcode
        if (!preg_match('/^[a-z]{2}(?:_[a-zA-Z]{2})?$/', $langcode)) {
            $langcode = 'en';
        }
        $foundlang = true;
        $lang_file = $lang_path . 'phpmailer.lang-' . $langcode . '.php';
        // There is no English translation file
        if ('en' !== $langcode) {
            // Make sure language file path is readable
            if (!static::isPermittedPath($lang_file) || !file_exists($lang_file)) {
                $foundlang = false;
            } else {
                // Overwrite language-specific strings.
                // This way we'll never have missing translation keys.
                $foundlang = include $lang_file;
            }
        }
        $this->language = $PHPMAILER_LANG;
 
        return (bool) $foundlang; // Returns false if language not found
    }
 
    public function getTranslations()
    {
        return $this->language;
    }
 
    public function addrAppend($type, $addr)
    {
        $addresses = [];
        foreach ($addr as $address) {
            $addresses[] = $this->addrFormat($address);
        }
 
        return $type . ': ' . implode(', ', $addresses) . static::$LE;
    }
 
    public function addrFormat($addr)
    {
        if (empty($addr[1])) { // No name provided
            return $this->secureHeader($addr[0]);
        }
 
        return $this->encodeHeader($this->secureHeader($addr[1]), 'phrase') .
            ' <' . $this->secureHeader($addr[0]) . '>';
    }
 
    public function wrapText($message, $length, $qp_mode = false)
    {
        if ($qp_mode) {
            $soft_break = sprintf(' =%s', static::$LE);
        } else {
            $soft_break = static::$LE;
        }
        // If utf-8 encoding is used, we will need to make sure we don't
        // split multibyte characters when we wrap
        $is_utf8 = static::CHARSET_UTF8 === strtolower($this->CharSet);
        $lelen = strlen(static::$LE);
        $crlflen = strlen(static::$LE);
 
        $message = static::normalizeBreaks($message);
        //Remove a trailing line break
        if (substr($message, -$lelen) === static::$LE) {
            $message = substr($message, 0, -$lelen);
        }
 
        //Split message into lines
        $lines = explode(static::$LE, $message);
        //Message will be rebuilt in here
        $message = '';
        foreach ($lines as $line) {
            $words = explode(' ', $line);
            $buf = '';
            $firstword = true;
            foreach ($words as $word) {
                if ($qp_mode && (strlen($word) > $length)) {
                    $space_left = $length - strlen($buf) - $crlflen;
                    if (!$firstword) {
                        if ($space_left > 20) {
                            $len = $space_left;
                            if ($is_utf8) {
                                $len = $this->utf8CharBoundary($word, $len);
                            } elseif ('=' === substr($word, $len - 1, 1)) {
                                --$len;
                            } elseif ('=' === substr($word, $len - 2, 1)) {
                                $len -= 2;
                            }
                            $part = substr($word, 0, $len);
                            $word = substr($word, $len);
                            $buf .= ' ' . $part;
                            $message .= $buf . sprintf('=%s', static::$LE);
                        } else {
                            $message .= $buf . $soft_break;
                        }
                        $buf = '';
                    }
                    while ($word !== '') {
                        if ($length <= 0) {
                            break;
                        }
                        $len = $length;
                        if ($is_utf8) {
                            $len = $this->utf8CharBoundary($word, $len);
                        } elseif ('=' === substr($word, $len - 1, 1)) {
                            --$len;
                        } elseif ('=' === substr($word, $len - 2, 1)) {
                            $len -= 2;
                        }
                        $part = substr($word, 0, $len);
                        $word = (string) substr($word, $len);
 
                        if ($word !== '') {
                            $message .= $part . sprintf('=%s', static::$LE);
                        } else {
                            $buf = $part;
                        }
                    }
                } else {
                    $buf_o = $buf;
                    if (!$firstword) {
                        $buf .= ' ';
                    }
                    $buf .= $word;
 
                    if ('' !== $buf_o && strlen($buf) > $length) {
                        $message .= $buf_o . $soft_break;
                        $buf = $word;
                    }
                }
                $firstword = false;
            }
            $message .= $buf . static::$LE;
        }
 
        return $message;
    }
 
    public function utf8CharBoundary($encodedText, $maxLength)
    {
        $foundSplitPos = false;
        $lookBack = 3;
        while (!$foundSplitPos) {
            $lastChunk = substr($encodedText, $maxLength - $lookBack, $lookBack);
            $encodedCharPos = strpos($lastChunk, '=');
            if (false !== $encodedCharPos) {
                // Found start of encoded character byte within $lookBack block.
                // Check the encoded byte value (the 2 chars after the '=')
                $hex = substr($encodedText, $maxLength - $lookBack + $encodedCharPos + 1, 2);
                $dec = hexdec($hex);
                if ($dec < 128) {
                    // Single byte character.
                    // If the encoded char was found at pos 0, it will fit
                    // otherwise reduce maxLength to start of the encoded char
                    if ($encodedCharPos > 0) {
                        $maxLength -= $lookBack - $encodedCharPos;
                    }
                    $foundSplitPos = true;
                } elseif ($dec >= 192) {
                    // First byte of a multi byte character
                    // Reduce maxLength to split at start of character
                    $maxLength -= $lookBack - $encodedCharPos;
                    $foundSplitPos = true;
                } elseif ($dec < 192) {
                    // Middle byte of a multi byte character, look further back
                    $lookBack += 3;
                }
            } else {
                // No encoded character found
                $foundSplitPos = true;
            }
        }
 
        return $maxLength;
    }
 
    public function setWordWrap()
    {
        if ($this->WordWrap < 1) {
            return;
        }
 
        switch ($this->message_type) {
            case 'alt':
            case 'alt_inline':
            case 'alt_attach':
            case 'alt_inline_attach':
                $this->AltBody = $this->wrapText($this->AltBody, $this->WordWrap);
                break;
            default:
                $this->Body = $this->wrapText($this->Body, $this->WordWrap);
                break;
        }
    }
 
    public function createHeader()
    {
        $result = '';
 
        $result .= $this->headerLine('Date', '' === $this->MessageDate ? self::rfcDate() : $this->MessageDate);
 
        // To be created automatically by mail()
        if ($this->SingleTo) {
            if ('mail' !== $this->Mailer) {
                foreach ($this->to as $toaddr) {
                    $this->SingleToArray[] = $this->addrFormat($toaddr);
                }
            }
        } elseif (count($this->to) > 0) {
            if ('mail' !== $this->Mailer) {
                $result .= $this->addrAppend('To', $this->to);
            }
        } elseif (count($this->cc) === 0) {
            $result .= $this->headerLine('To', 'undisclosed-recipients:;');
        }
 
        $result .= $this->addrAppend('From', [[trim($this->From), $this->FromName]]);
 
        // sendmail and mail() extract Cc from the header before sending
        if (count($this->cc) > 0) {
            $result .= $this->addrAppend('Cc', $this->cc);
        }
 
        // sendmail and mail() extract Bcc from the header before sending
        if ((
                'sendmail' === $this->Mailer || 'qmail' === $this->Mailer || 'mail' === $this->Mailer
            )
            && count($this->bcc) > 0
        ) {
            $result .= $this->addrAppend('Bcc', $this->bcc);
        }
 
        if (count($this->ReplyTo) > 0) {
            $result .= $this->addrAppend('Reply-To', $this->ReplyTo);
        }
 
        // mail() sets the subject itself
        if ('mail' !== $this->Mailer) {
            $result .= $this->headerLine('Subject', $this->encodeHeader($this->secureHeader($this->Subject)));
        }
 
        // Only allow a custom message ID if it conforms to RFC 5322 section 3.6.4
        // https://tools.ietf.org/html/rfc5322#section-3.6.4
        if ('' !== $this->MessageID && preg_match('/^<.*@.*>$/', $this->MessageID)) {
            $this->lastMessageID = $this->MessageID;
        } else {
            $this->lastMessageID = sprintf('<%s@%s>', $this->uniqueid, $this->serverHostname());
        }
        $result .= $this->headerLine('Message-ID', $this->lastMessageID);
        if (null !== $this->Priority) {
            $result .= $this->headerLine('X-Priority', $this->Priority);
        }
        if ('' === $this->XMailer) {
            $result .= $this->headerLine(
                'X-Mailer',
                'PHPMailer ' . self::VERSION . ' (https://github.com/PHPMailer/PHPMailer)'
            );
        } else {
            $myXmailer = trim($this->XMailer);
            if ($myXmailer) {
                $result .= $this->headerLine('X-Mailer', $myXmailer);
            }
        }
 
        if ('' !== $this->ConfirmReadingTo) {
            $result .= $this->headerLine('Disposition-Notification-To', '<' . $this->ConfirmReadingTo . '>');
        }
 
        // Add custom headers
        foreach ($this->CustomHeader as $header) {
            $result .= $this->headerLine(
                trim($header[0]),
                $this->encodeHeader(trim($header[1]))
            );
        }
        if (!$this->sign_key_file) {
            $result .= $this->headerLine('MIME-Version', '1.0');
            $result .= $this->getMailMIME();
        }
 
        return $result;
    }
 
    public function getMailMIME()
    {
        $result = '';
        $ismultipart = true;
        switch ($this->message_type) {
            case 'inline':
                $result .= $this->headerLine('Content-Type', static::CONTENT_TYPE_MULTIPART_RELATED . ';');
                $result .= $this->textLine(' boundary="' . $this->boundary[1] . '"');
                break;
            case 'attach':
            case 'inline_attach':
            case 'alt_attach':
            case 'alt_inline_attach':
                $result .= $this->headerLine('Content-Type', static::CONTENT_TYPE_MULTIPART_MIXED . ';');
                $result .= $this->textLine(' boundary="' . $this->boundary[1] . '"');
                break;
            case 'alt':
            case 'alt_inline':
                $result .= $this->headerLine('Content-Type', static::CONTENT_TYPE_MULTIPART_ALTERNATIVE . ';');
                $result .= $this->textLine(' boundary="' . $this->boundary[1] . '"');
                break;
            default:
                // Catches case 'plain': and case '':
                $result .= $this->textLine('Content-Type: ' . $this->ContentType . '; charset=' . $this->CharSet);
                $ismultipart = false;
                break;
        }
        // RFC1341 part 5 says 7bit is assumed if not specified
        if (static::ENCODING_7BIT !== $this->Encoding) {
            // RFC 2045 section 6.4 says multipart MIME parts may only use 7bit, 8bit or binary CTE
            if ($ismultipart) {
                if (static::ENCODING_8BIT === $this->Encoding) {
                    $result .= $this->headerLine('Content-Transfer-Encoding', static::ENCODING_8BIT);
                }
                // The only remaining alternatives are quoted-printable and base64, which are both 7bit compatible
            } else {
                $result .= $this->headerLine('Content-Transfer-Encoding', $this->Encoding);
            }
        }
 
        if ('mail' !== $this->Mailer) {
//            $result .= static::$LE;
        }
 
        return $result;
    }
 
    public function getSentMIMEMessage()
    {
        return static::stripTrailingWSP($this->MIMEHeader . $this->mailHeader) .
            static::$LE . static::$LE . $this->MIMEBody;
    }
 
    protected function generateId()
    {
        $len = 32; //32 bytes = 256 bits
        $bytes = '';
        if (function_exists('random_bytes')) {
            try {
                $bytes = random_bytes($len);
            } catch (\Exception $e) {
                //Do nothing
            }
        } elseif (function_exists('openssl_random_pseudo_bytes')) {
            $bytes = openssl_random_pseudo_bytes($len);
        }
        if ($bytes === '') {
            //We failed to produce a proper random string, so make do.
            //Use a hash to force the length to the same as the other methods
            $bytes = hash('sha256', uniqid((string) mt_rand(), true), true);
        }
 
        //We don't care about messing up base64 format here, just want a random string
        return str_replace(['=', '+', '/'], '', base64_encode(hash('sha256', $bytes, true)));
    }
 
    public function createBody()
    {
        $body = '';
        //Create unique IDs and preset boundaries
        $this->uniqueid = $this->generateId();
        $this->boundary[1] = 'b1_' . $this->uniqueid;
        $this->boundary[2] = 'b2_' . $this->uniqueid;
        $this->boundary[3] = 'b3_' . $this->uniqueid;
 
        if ($this->sign_key_file) {
            $body .= $this->getMailMIME() . static::$LE;
        }
 
        $this->setWordWrap();
 
        $bodyEncoding = $this->Encoding;
        $bodyCharSet = $this->CharSet;
        //Can we do a 7-bit downgrade?
        if (static::ENCODING_8BIT === $bodyEncoding && !$this->has8bitChars($this->Body)) {
            $bodyEncoding = static::ENCODING_7BIT;
            //All ISO 8859, Windows codepage and UTF-8 charsets are ascii compatible up to 7-bit
            $bodyCharSet = static::CHARSET_ASCII;
        }
        //If lines are too long, and we're not already using an encoding that will shorten them,
        //change to quoted-printable transfer encoding for the body part only
        if (static::ENCODING_BASE64 !== $this->Encoding && static::hasLineLongerThanMax($this->Body)) {
            $bodyEncoding = static::ENCODING_QUOTED_PRINTABLE;
        }
 
        $altBodyEncoding = $this->Encoding;
        $altBodyCharSet = $this->CharSet;
        //Can we do a 7-bit downgrade?
        if (static::ENCODING_8BIT === $altBodyEncoding && !$this->has8bitChars($this->AltBody)) {
            $altBodyEncoding = static::ENCODING_7BIT;
            //All ISO 8859, Windows codepage and UTF-8 charsets are ascii compatible up to 7-bit
            $altBodyCharSet = static::CHARSET_ASCII;
        }
        //If lines are too long, and we're not already using an encoding that will shorten them,
        //change to quoted-printable transfer encoding for the alt body part only
        if (static::ENCODING_BASE64 !== $altBodyEncoding && static::hasLineLongerThanMax($this->AltBody)) {
            $altBodyEncoding = static::ENCODING_QUOTED_PRINTABLE;
        }
        //Use this as a preamble in all multipart message types
        $mimepre = 'This is a multi-part message in MIME format.' . static::$LE . static::$LE;
        switch ($this->message_type) {
            case 'inline':
                $body .= $mimepre;
                $body .= $this->getBoundary($this->boundary[1], $bodyCharSet, '', $bodyEncoding);
                $body .= $this->encodeString($this->Body, $bodyEncoding);
                $body .= static::$LE;
                $body .= $this->attachAll('inline', $this->boundary[1]);
                break;
            case 'attach':
                $body .= $mimepre;
                $body .= $this->getBoundary($this->boundary[1], $bodyCharSet, '', $bodyEncoding);
                $body .= $this->encodeString($this->Body, $bodyEncoding);
                $body .= static::$LE;
                $body .= $this->attachAll('attachment', $this->boundary[1]);
                break;
            case 'inline_attach':
                $body .= $mimepre;
                $body .= $this->textLine('--' . $this->boundary[1]);
                $body .= $this->headerLine('Content-Type', static::CONTENT_TYPE_MULTIPART_RELATED . ';');
                $body .= $this->textLine(' boundary="' . $this->boundary[2] . '";');
                $body .= $this->textLine(' type="' . static::CONTENT_TYPE_TEXT_HTML . '"');
                $body .= static::$LE;
                $body .= $this->getBoundary($this->boundary[2], $bodyCharSet, '', $bodyEncoding);
                $body .= $this->encodeString($this->Body, $bodyEncoding);
                $body .= static::$LE;
                $body .= $this->attachAll('inline', $this->boundary[2]);
                $body .= static::$LE;
                $body .= $this->attachAll('attachment', $this->boundary[1]);
                break;
            case 'alt':
                $body .= $mimepre;
                $body .= $this->getBoundary(
                    $this->boundary[1],
                    $altBodyCharSet,
                    static::CONTENT_TYPE_PLAINTEXT,
                    $altBodyEncoding
                );
                $body .= $this->encodeString($this->AltBody, $altBodyEncoding);
                $body .= static::$LE;
                $body .= $this->getBoundary(
                    $this->boundary[1],
                    $bodyCharSet,
                    static::CONTENT_TYPE_TEXT_HTML,
                    $bodyEncoding
                );
                $body .= $this->encodeString($this->Body, $bodyEncoding);
                $body .= static::$LE;
                if (!empty($this->Ical)) {
                    $method = static::ICAL_METHOD_REQUEST;
                    foreach (static::$IcalMethods as $imethod) {
                        if (stripos($this->Ical, 'METHOD:' . $imethod) !== false) {
                            $method = $imethod;
                            break;
                        }
                    }
                    $body .= $this->getBoundary(
                        $this->boundary[1],
                        '',
                        static::CONTENT_TYPE_TEXT_CALENDAR . '; method=' . $method,
                        ''
                    );
                    $body .= $this->encodeString($this->Ical, $this->Encoding);
                    $body .= static::$LE;
                }
                $body .= $this->endBoundary($this->boundary[1]);
                break;
            case 'alt_inline':
                $body .= $mimepre;
                $body .= $this->getBoundary(
                    $this->boundary[1],
                    $altBodyCharSet,
                    static::CONTENT_TYPE_PLAINTEXT,
                    $altBodyEncoding
                );
                $body .= $this->encodeString($this->AltBody, $altBodyEncoding);
                $body .= static::$LE;
                $body .= $this->textLine('--' . $this->boundary[1]);
                $body .= $this->headerLine('Content-Type', static::CONTENT_TYPE_MULTIPART_RELATED . ';');
                $body .= $this->textLine(' boundary="' . $this->boundary[2] . '";');
                $body .= $this->textLine(' type="' . static::CONTENT_TYPE_TEXT_HTML . '"');
                $body .= static::$LE;
                $body .= $this->getBoundary(
                    $this->boundary[2],
                    $bodyCharSet,
                    static::CONTENT_TYPE_TEXT_HTML,
                    $bodyEncoding
                );
                $body .= $this->encodeString($this->Body, $bodyEncoding);
                $body .= static::$LE;
                $body .= $this->attachAll('inline', $this->boundary[2]);
                $body .= static::$LE;
                $body .= $this->endBoundary($this->boundary[1]);
                break;
            case 'alt_attach':
                $body .= $mimepre;
                $body .= $this->textLine('--' . $this->boundary[1]);
                $body .= $this->headerLine('Content-Type', static::CONTENT_TYPE_MULTIPART_ALTERNATIVE . ';');
                $body .= $this->textLine(' boundary="' . $this->boundary[2] . '"');
                $body .= static::$LE;
                $body .= $this->getBoundary(
                    $this->boundary[2],
                    $altBodyCharSet,
                    static::CONTENT_TYPE_PLAINTEXT,
                    $altBodyEncoding
                );
                $body .= $this->encodeString($this->AltBody, $altBodyEncoding);
                $body .= static::$LE;
                $body .= $this->getBoundary(
                    $this->boundary[2],
                    $bodyCharSet,
                    static::CONTENT_TYPE_TEXT_HTML,
                    $bodyEncoding
                );
                $body .= $this->encodeString($this->Body, $bodyEncoding);
                $body .= static::$LE;
                if (!empty($this->Ical)) {
                    $method = static::ICAL_METHOD_REQUEST;
                    foreach (static::$IcalMethods as $imethod) {
                        if (stripos($this->Ical, 'METHOD:' . $imethod) !== false) {
                            $method = $imethod;
                            break;
                        }
                    }
                    $body .= $this->getBoundary(
                        $this->boundary[2],
                        '',
                        static::CONTENT_TYPE_TEXT_CALENDAR . '; method=' . $method,
                        ''
                    );
                    $body .= $this->encodeString($this->Ical, $this->Encoding);
                }
                $body .= $this->endBoundary($this->boundary[2]);
                $body .= static::$LE;
                $body .= $this->attachAll('attachment', $this->boundary[1]);
                break;
            case 'alt_inline_attach':
                $body .= $mimepre;
                $body .= $this->textLine('--' . $this->boundary[1]);
                $body .= $this->headerLine('Content-Type', static::CONTENT_TYPE_MULTIPART_ALTERNATIVE . ';');
                $body .= $this->textLine(' boundary="' . $this->boundary[2] . '"');
                $body .= static::$LE;
                $body .= $this->getBoundary(
                    $this->boundary[2],
                    $altBodyCharSet,
                    static::CONTENT_TYPE_PLAINTEXT,
                    $altBodyEncoding
                );
                $body .= $this->encodeString($this->AltBody, $altBodyEncoding);
                $body .= static::$LE;
                $body .= $this->textLine('--' . $this->boundary[2]);
                $body .= $this->headerLine('Content-Type', static::CONTENT_TYPE_MULTIPART_RELATED . ';');
                $body .= $this->textLine(' boundary="' . $this->boundary[3] . '";');
                $body .= $this->textLine(' type="' . static::CONTENT_TYPE_TEXT_HTML . '"');
                $body .= static::$LE;
                $body .= $this->getBoundary(
                    $this->boundary[3],
                    $bodyCharSet,
                    static::CONTENT_TYPE_TEXT_HTML,
                    $bodyEncoding
                );
                $body .= $this->encodeString($this->Body, $bodyEncoding);
                $body .= static::$LE;
                $body .= $this->attachAll('inline', $this->boundary[3]);
                $body .= static::$LE;
                $body .= $this->endBoundary($this->boundary[2]);
                $body .= static::$LE;
                $body .= $this->attachAll('attachment', $this->boundary[1]);
                break;
            default:
                // Catch case 'plain' and case '', applies to simple `text/plain` and `text/html` body content types
                //Reset the `Encoding` property in case we changed it for line length reasons
                $this->Encoding = $bodyEncoding;
                $body .= $this->encodeString($this->Body, $this->Encoding);
                break;
        }
 
        if ($this->isError()) {
            $body = '';
            if ($this->exceptions) {
                throw new Exception($this->lang('empty_message'), self::STOP_CRITICAL);
            }
        } elseif ($this->sign_key_file) {
            try {
                if (!defined('PKCS7_TEXT')) {
                    throw new Exception($this->lang('extension_missing') . 'openssl');
                }
 
                $file = tempnam(sys_get_temp_dir(), 'srcsign');
                $signed = tempnam(sys_get_temp_dir(), 'mailsign');
                file_put_contents($file, $body);
 
                //Workaround for PHP bug https://bugs.php.net/bug.php?id=69197
                if (empty($this->sign_extracerts_file)) {
                    $sign = @openssl_pkcs7_sign(
                        $file,
                        $signed,
                        'file://' . realpath($this->sign_cert_file),
                        ['file://' . realpath($this->sign_key_file), $this->sign_key_pass],
                        []
                    );
                } else {
                    $sign = @openssl_pkcs7_sign(
                        $file,
                        $signed,
                        'file://' . realpath($this->sign_cert_file),
                        ['file://' . realpath($this->sign_key_file), $this->sign_key_pass],
                        [],
                        PKCS7_DETACHED,
                        $this->sign_extracerts_file
                    );
                }
 
                @unlink($file);
                if ($sign) {
                    $body = file_get_contents($signed);
                    @unlink($signed);
                    //The message returned by openssl contains both headers and body, so need to split them up
                    $parts = explode("\n\n", $body, 2);
                    $this->MIMEHeader .= $parts[0] . static::$LE . static::$LE;
                    $body = $parts[1];
                } else {
                    @unlink($signed);
                    throw new Exception($this->lang('signing') . openssl_error_string());
                }
            } catch (Exception $exc) {
                $body = '';
                if ($this->exceptions) {
                    throw $exc;
                }
            }
        }
 
        return $body;
    }
 
    protected function getBoundary($boundary, $charSet, $contentType, $encoding)
    {
        $result = '';
        if ('' === $charSet) {
            $charSet = $this->CharSet;
        }
        if ('' === $contentType) {
            $contentType = $this->ContentType;
        }
        if ('' === $encoding) {
            $encoding = $this->Encoding;
        }
        $result .= $this->textLine('--' . $boundary);
        $result .= sprintf('Content-Type: %s; charset=%s', $contentType, $charSet);
        $result .= static::$LE;
        // RFC1341 part 5 says 7bit is assumed if not specified
        if (static::ENCODING_7BIT !== $encoding) {
            $result .= $this->headerLine('Content-Transfer-Encoding', $encoding);
        }
        $result .= static::$LE;
 
        return $result;
    }
 
    protected function endBoundary($boundary)
    {
        return static::$LE . '--' . $boundary . '--' . static::$LE;
    }
 
    protected function setMessageType()
    {
        $type = [];
        if ($this->alternativeExists()) {
            $type[] = 'alt';
        }
        if ($this->inlineImageExists()) {
            $type[] = 'inline';
        }
        if ($this->attachmentExists()) {
            $type[] = 'attach';
        }
        $this->message_type = implode('_', $type);
        if ('' === $this->message_type) {
            //The 'plain' message_type refers to the message having a single body element, not that it is plain-text
            $this->message_type = 'plain';
        }
    }
 
    public function headerLine($name, $value)
    {
        return $name . ': ' . $value . static::$LE;
    }
 
    public function textLine($value)
    {
        return $value . static::$LE;
    }
 
    public function addAttachment(
        $path,
        $name = '',
        $encoding = self::ENCODING_BASE64,
        $type = '',
        $disposition = 'attachment'
    ) {
        try {
            if (!static::isPermittedPath($path) || !@is_file($path) || !is_readable($path)) {
                throw new Exception($this->lang('file_access') . $path, self::STOP_CONTINUE);
            }
 
            // If a MIME type is not specified, try to work it out from the file name
            if ('' === $type) {
                $type = static::filenameToType($path);
            }
 
            $filename = (string) static::mb_pathinfo($path, PATHINFO_BASENAME);
            if ('' === $name) {
                $name = $filename;
            }
 
            if (!$this->validateEncoding($encoding)) {
                throw new Exception($this->lang('encoding') . $encoding);
            }
 
            $this->attachment[] = [
                0 => $path,
                1 => $filename,
                2 => $name,
                3 => $encoding,
                4 => $type,
                5 => false, // isStringAttachment
                6 => $disposition,
                7 => $name,
            ];
        } catch (Exception $exc) {
            $this->setError($exc->getMessage());
            $this->edebug($exc->getMessage());
            if ($this->exceptions) {
                throw $exc;
            }
 
            return false;
        }
 
        return true;
    }
 
    public function getAttachments()
    {
        return $this->attachment;
    }
 
    protected function attachAll($disposition_type, $boundary)
    {
        // Return text of body
        $mime = [];
        $cidUniq = [];
        $incl = [];
 
        // Add all attachments
        foreach ($this->attachment as $attachment) {
            // Check if it is a valid disposition_filter
            if ($attachment[6] === $disposition_type) {
                // Check for string attachment
                $string = '';
                $path = '';
                $bString = $attachment[5];
                if ($bString) {
                    $string = $attachment[0];
                } else {
                    $path = $attachment[0];
                }
 
                $inclhash = hash('sha256', serialize($attachment));
                if (in_array($inclhash, $incl, true)) {
                    continue;
                }
                $incl[] = $inclhash;
                $name = $attachment[2];
                $encoding = $attachment[3];
                $type = $attachment[4];
                $disposition = $attachment[6];
                $cid = $attachment[7];
                if ('inline' === $disposition && array_key_exists($cid, $cidUniq)) {
                    continue;
                }
                $cidUniq[$cid] = true;
 
                $mime[] = sprintf('--%s%s', $boundary, static::$LE);
                //Only include a filename property if we have one
                if (!empty($name)) {
                    $mime[] = sprintf(
                        'Content-Type: %s; name=%s%s',
                        $type,
                        static::quotedString($this->encodeHeader($this->secureHeader($name))),
                        static::$LE
                    );
                } else {
                    $mime[] = sprintf(
                        'Content-Type: %s%s',
                        $type,
                        static::$LE
                    );
                }
                // RFC1341 part 5 says 7bit is assumed if not specified
                if (static::ENCODING_7BIT !== $encoding) {
                    $mime[] = sprintf('Content-Transfer-Encoding: %s%s', $encoding, static::$LE);
                }
 
                //Only set Content-IDs on inline attachments
                if ((string) $cid !== '' && $disposition === 'inline') {
                    $mime[] = 'Content-ID: <' . $this->encodeHeader($this->secureHeader($cid)) . '>' . static::$LE;
                }
 
                // Allow for bypassing the Content-Disposition header
                if (!empty($disposition)) {
                    $encoded_name = $this->encodeHeader($this->secureHeader($name));
                    if (!empty($encoded_name)) {
                        $mime[] = sprintf(
                            'Content-Disposition: %s; filename=%s%s',
                            $disposition,
                            static::quotedString($encoded_name),
                            static::$LE . static::$LE
                        );
                    } else {
                        $mime[] = sprintf(
                            'Content-Disposition: %s%s',
                            $disposition,
                            static::$LE . static::$LE
                        );
                    }
                } else {
                    $mime[] = static::$LE;
                }
 
                // Encode as string attachment
                if ($bString) {
                    $mime[] = $this->encodeString($string, $encoding);
                } else {
                    $mime[] = $this->encodeFile($path, $encoding);
                }
                if ($this->isError()) {
                    return '';
                }
                $mime[] = static::$LE;
            }
        }
 
        $mime[] = sprintf('--%s--%s', $boundary, static::$LE);
 
        return implode('', $mime);
    }
 
    protected function encodeFile($path, $encoding = self::ENCODING_BASE64)
    {
        try {
            if (!static::isPermittedPath($path) || !file_exists($path) || !is_readable($path)) {
                throw new Exception($this->lang('file_open') . $path, self::STOP_CONTINUE);
            }
            $file_buffer = file_get_contents($path);
            if (false === $file_buffer) {
                throw new Exception($this->lang('file_open') . $path, self::STOP_CONTINUE);
            }
            $file_buffer = $this->encodeString($file_buffer, $encoding);
 
            return $file_buffer;
        } catch (Exception $exc) {
            $this->setError($exc->getMessage());
            $this->edebug($exc->getMessage());
            if ($this->exceptions) {
                throw $exc;
            }
 
            return '';
        }
    }
 
    public function encodeString($str, $encoding = self::ENCODING_BASE64)
    {
        $encoded = '';
        switch (strtolower($encoding)) {
            case static::ENCODING_BASE64:
                $encoded = chunk_split(
                    base64_encode($str),
                    static::STD_LINE_LENGTH,
                    static::$LE
                );
                break;
            case static::ENCODING_7BIT:
            case static::ENCODING_8BIT:
                $encoded = static::normalizeBreaks($str);
                // Make sure it ends with a line break
                if (substr($encoded, -(strlen(static::$LE))) !== static::$LE) {
                    $encoded .= static::$LE;
                }
                break;
            case static::ENCODING_BINARY:
                $encoded = $str;
                break;
            case static::ENCODING_QUOTED_PRINTABLE:
                $encoded = $this->encodeQP($str);
                break;
            default:
                $this->setError($this->lang('encoding') . $encoding);
                if ($this->exceptions) {
                    throw new Exception($this->lang('encoding') . $encoding);
                }
                break;
        }
 
        return $encoded;
    }
 
    public function encodeHeader($str, $position = 'text')
    {
        $matchcount = 0;
        switch (strtolower($position)) {
            case 'phrase':
                if (!preg_match('/[\200-\377]/', $str)) {
                    // Can't use addslashes as we don't know the value of magic_quotes_sybase
                    $encoded = addcslashes($str, "\0..\37\177\\\"");
                    if (($str === $encoded) && !preg_match('/[^A-Za-z0-9!#$%&\'*+\/=?^_`{|}~ -]/', $str)) {
                        return $encoded;
                    }
 
                    return "\"$encoded\"";
                }
                $matchcount = preg_match_all('/[^\040\041\043-\133\135-\176]/', $str, $matches);
                break;
            /* @noinspection PhpMissingBreakStatementInspection */
            case 'comment':
                $matchcount = preg_match_all('/[()"]/', $str, $matches);
            //fallthrough
            case 'text':
            default:
                $matchcount += preg_match_all('/[\000-\010\013\014\016-\037\177-\377]/', $str, $matches);
                break;
        }
 
        if ($this->has8bitChars($str)) {
            $charset = $this->CharSet;
        } else {
            $charset = static::CHARSET_ASCII;
        }
 
        // Q/B encoding adds 8 chars and the charset ("` =?<charset>?[QB]?<content>?=`").
        $overhead = 8 + strlen($charset);
 
        if ('mail' === $this->Mailer) {
            $maxlen = static::MAIL_MAX_LINE_LENGTH - $overhead;
        } else {
            $maxlen = static::MAX_LINE_LENGTH - $overhead;
        }
 
        // Select the encoding that produces the shortest output and/or prevents corruption.
        if ($matchcount > strlen($str) / 3) {
            // More than 1/3 of the content needs encoding, use B-encode.
            $encoding = 'B';
        } elseif ($matchcount > 0) {
            // Less than 1/3 of the content needs encoding, use Q-encode.
            $encoding = 'Q';
        } elseif (strlen($str) > $maxlen) {
            // No encoding needed, but value exceeds max line length, use Q-encode to prevent corruption.
            $encoding = 'Q';
        } else {
            // No reformatting needed
            $encoding = false;
        }
 
        switch ($encoding) {
            case 'B':
                if ($this->hasMultiBytes($str)) {
                    // Use a custom function which correctly encodes and wraps long
                    // multibyte strings without breaking lines within a character
                    $encoded = $this->base64EncodeWrapMB($str, "\n");
                } else {
                    $encoded = base64_encode($str);
                    $maxlen -= $maxlen % 4;
                    $encoded = trim(chunk_split($encoded, $maxlen, "\n"));
                }
                $encoded = preg_replace('/^(.*)$/m', ' =?' . $charset . "?$encoding?\\1?=", $encoded);
                break;
            case 'Q':
                $encoded = $this->encodeQ($str, $position);
                $encoded = $this->wrapText($encoded, $maxlen, true);
                $encoded = str_replace('=' . static::$LE, "\n", trim($encoded));
                $encoded = preg_replace('/^(.*)$/m', ' =?' . $charset . "?$encoding?\\1?=", $encoded);
                break;
            default:
                return $str;
        }
 
        return trim(static::normalizeBreaks($encoded));
    }
 
    public function hasMultiBytes($str)
    {
        if (function_exists('mb_strlen')) {
            return strlen($str) > mb_strlen($str, $this->CharSet);
        }
 
        // Assume no multibytes (we can't handle without mbstring functions anyway)
        return false;
    }
 
    public function has8bitChars($text)
    {
        return (bool) preg_match('/[\x80-\xFF]/', $text);
    }
 
    public function base64EncodeWrapMB($str, $linebreak = null)
    {
        $start = '=?' . $this->CharSet . '?B?';
        $end = '?=';
        $encoded = '';
        if (null === $linebreak) {
            $linebreak = static::$LE;
        }
 
        $mb_length = mb_strlen($str, $this->CharSet);
        // Each line must have length <= 75, including $start and $end
        $length = 75 - strlen($start) - strlen($end);
        // Average multi-byte ratio
        $ratio = $mb_length / strlen($str);
        // Base64 has a 4:3 ratio
        $avgLength = floor($length * $ratio * .75);
 
        $offset = 0;
        for ($i = 0; $i < $mb_length; $i += $offset) {
            $lookBack = 0;
            do {
                $offset = $avgLength - $lookBack;
                $chunk = mb_substr($str, $i, $offset, $this->CharSet);
                $chunk = base64_encode($chunk);
                ++$lookBack;
            } while (strlen($chunk) > $length);
            $encoded .= $chunk . $linebreak;
        }
 
        // Chomp the last linefeed
        return substr($encoded, 0, -strlen($linebreak));
    }
 
    public function encodeQP($string)
    {
        return static::normalizeBreaks(quoted_printable_encode($string));
    }
 
    public function encodeQ($str, $position = 'text')
    {
        // There should not be any EOL in the string
        $pattern = '';
        $encoded = str_replace(["\r", "\n"], '', $str);
        switch (strtolower($position)) {
            case 'phrase':
                // RFC 2047 section 5.3
                $pattern = '^A-Za-z0-9!*+\/ -';
                break;
            /*
             * RFC 2047 section 5.2.
             * Build $pattern without including delimiters and []
             */
            /* @noinspection PhpMissingBreakStatementInspection */
            case 'comment':
                $pattern = '\‍(\‍)"';
            /* Intentional fall through */
            case 'text':
            default:
                // RFC 2047 section 5.1
                // Replace every high ascii, control, =, ? and _ characters
                $pattern = '\000-\011\013\014\016-\037\075\077\137\177-\377' . $pattern;
                break;
        }
        $matches = [];
        if (preg_match_all("/[{$pattern}]/", $encoded, $matches)) {
            // If the string contains an '=', make sure it's the first thing we replace
            // so as to avoid double-encoding
            $eqkey = array_search('=', $matches[0], true);
            if (false !== $eqkey) {
                unset($matches[0][$eqkey]);
                array_unshift($matches[0], '=');
            }
            foreach (array_unique($matches[0]) as $char) {
                $encoded = str_replace($char, '=' . sprintf('%02X', ord($char)), $encoded);
            }
        }
        // Replace spaces with _ (more readable than =20)
        // RFC 2047 section 4.2(2)
        return str_replace(' ', '_', $encoded);
    }
 
    public function addStringAttachment(
        $string,
        $filename,
        $encoding = self::ENCODING_BASE64,
        $type = '',
        $disposition = 'attachment'
    ) {
        try {
            // If a MIME type is not specified, try to work it out from the file name
            if ('' === $type) {
                $type = static::filenameToType($filename);
            }
 
            if (!$this->validateEncoding($encoding)) {
                throw new Exception($this->lang('encoding') . $encoding);
            }
 
            // Append to $attachment array
            $this->attachment[] = [
                0 => $string,
                1 => $filename,
                2 => static::mb_pathinfo($filename, PATHINFO_BASENAME),
                3 => $encoding,
                4 => $type,
                5 => true, // isStringAttachment
                6 => $disposition,
                7 => 0,
            ];
        } catch (Exception $exc) {
            $this->setError($exc->getMessage());
            $this->edebug($exc->getMessage());
            if ($this->exceptions) {
                throw $exc;
            }
 
            return false;
        }
 
        return true;
    }
 
    public function addEmbeddedImage(
        $path,
        $cid,
        $name = '',
        $encoding = self::ENCODING_BASE64,
        $type = '',
        $disposition = 'inline'
    ) {
        try {
            if (!static::isPermittedPath($path) || !@is_file($path) || !is_readable($path)) {
                throw new Exception($this->lang('file_access') . $path, self::STOP_CONTINUE);
            }
 
            // If a MIME type is not specified, try to work it out from the file name
            if ('' === $type) {
                $type = static::filenameToType($path);
            }
 
            if (!$this->validateEncoding($encoding)) {
                throw new Exception($this->lang('encoding') . $encoding);
            }
 
            $filename = (string) static::mb_pathinfo($path, PATHINFO_BASENAME);
            if ('' === $name) {
                $name = $filename;
            }
 
            // Append to $attachment array
            $this->attachment[] = [
                0 => $path,
                1 => $filename,
                2 => $name,
                3 => $encoding,
                4 => $type,
                5 => false, // isStringAttachment
                6 => $disposition,
                7 => $cid,
            ];
        } catch (Exception $exc) {
            $this->setError($exc->getMessage());
            $this->edebug($exc->getMessage());
            if ($this->exceptions) {
                throw $exc;
            }
 
            return false;
        }
 
        return true;
    }
 
    public function addStringEmbeddedImage(
        $string,
        $cid,
        $name = '',
        $encoding = self::ENCODING_BASE64,
        $type = '',
        $disposition = 'inline'
    ) {
        try {
            // If a MIME type is not specified, try to work it out from the name
            if ('' === $type && !empty($name)) {
                $type = static::filenameToType($name);
            }
 
            if (!$this->validateEncoding($encoding)) {
                throw new Exception($this->lang('encoding') . $encoding);
            }
 
            // Append to $attachment array
            $this->attachment[] = [
                0 => $string,
                1 => $name,
                2 => $name,
                3 => $encoding,
                4 => $type,
                5 => true, // isStringAttachment
                6 => $disposition,
                7 => $cid,
            ];
        } catch (Exception $exc) {
            $this->setError($exc->getMessage());
            $this->edebug($exc->getMessage());
            if ($this->exceptions) {
                throw $exc;
            }
 
            return false;
        }
 
        return true;
    }
 
    protected function validateEncoding($encoding)
    {
        return in_array(
            $encoding,
            [
                self::ENCODING_7BIT,
                self::ENCODING_QUOTED_PRINTABLE,
                self::ENCODING_BASE64,
                self::ENCODING_8BIT,
                self::ENCODING_BINARY,
            ],
            true
        );
    }
 
    protected function cidExists($cid)
    {
        foreach ($this->attachment as $attachment) {
            if ('inline' === $attachment[6] && $cid === $attachment[7]) {
                return true;
            }
        }
 
        return false;
    }
 
    public function inlineImageExists()
    {
        foreach ($this->attachment as $attachment) {
            if ('inline' === $attachment[6]) {
                return true;
            }
        }
 
        return false;
    }
 
    public function attachmentExists()
    {
        foreach ($this->attachment as $attachment) {
            if ('attachment' === $attachment[6]) {
                return true;
            }
        }
 
        return false;
    }
 
    public function alternativeExists()
    {
        return !empty($this->AltBody);
    }
 
    public function clearQueuedAddresses($kind)
    {
        $this->RecipientsQueue = array_filter(
            $this->RecipientsQueue,
            static function ($params) use ($kind) {
                return $params[0] !== $kind;
            }
        );
    }
 
    public function clearAddresses()
    {
        foreach ($this->to as $to) {
            unset($this->all_recipients[strtolower($to[0])]);
        }
        $this->to = [];
        $this->clearQueuedAddresses('to');
    }
 
    public function clearCCs()
    {
        foreach ($this->cc as $cc) {
            unset($this->all_recipients[strtolower($cc[0])]);
        }
        $this->cc = [];
        $this->clearQueuedAddresses('cc');
    }
 
    public function clearBCCs()
    {
        foreach ($this->bcc as $bcc) {
            unset($this->all_recipients[strtolower($bcc[0])]);
        }
        $this->bcc = [];
        $this->clearQueuedAddresses('bcc');
    }
 
    public function clearReplyTos()
    {
        $this->ReplyTo = [];
        $this->ReplyToQueue = [];
    }
 
    public function clearAllRecipients()
    {
        $this->to = [];
        $this->cc = [];
        $this->bcc = [];
        $this->all_recipients = [];
        $this->RecipientsQueue = [];
    }
 
    public function clearAttachments()
    {
        $this->attachment = [];
    }
 
    public function clearCustomHeaders()
    {
        $this->CustomHeader = [];
    }
 
    protected function setError($msg)
    {
        ++$this->error_count;
        if ('smtp' === $this->Mailer && null !== $this->smtp) {
            $lasterror = $this->smtp->getError();
            if (!empty($lasterror['error'])) {
                $msg .= $this->lang('smtp_error') . $lasterror['error'];
                if (!empty($lasterror['detail'])) {
                    $msg .= ' Detail: ' . $lasterror['detail'];
                }
                if (!empty($lasterror['smtp_code'])) {
                    $msg .= ' SMTP code: ' . $lasterror['smtp_code'];
                }
                if (!empty($lasterror['smtp_code_ex'])) {
                    $msg .= ' Additional SMTP info: ' . $lasterror['smtp_code_ex'];
                }
            }
        }
        $this->ErrorInfo = $msg;
    }
 
    public static function rfcDate()
    {
        // Set the time zone to whatever the default is to avoid 500 errors
        // Will default to UTC if it's not set properly in php.ini
        date_default_timezone_set(@date_default_timezone_get());
 
        return date('D, j M Y H:i:s O');
    }
 
    protected function serverHostname()
    {
        $result = '';
        if (!empty($this->Hostname)) {
            $result = $this->Hostname;
        } elseif (isset($_SERVER) && array_key_exists('SERVER_NAME', $_SERVER)) {
            $result = $_SERVER['SERVER_NAME'];
        } elseif (function_exists('gethostname') && gethostname() !== false) {
            $result = gethostname();
        } elseif (php_uname('n') !== false) {
            $result = php_uname('n');
        }
        if (!static::isValidHost($result)) {
            return 'localhost.localdomain';
        }
 
        return $result;
    }
 
    public static function isValidHost($host)
    {
        //Simple syntax limits
        if (empty($host)
            || !is_string($host)
            || strlen($host) > 256
            || !preg_match('/^([a-zA-Z\d.-]*|\[[a-fA-F\d:]+])$/', $host)
        ) {
            return false;
        }
        //Looks like a bracketed IPv6 address
        if (strlen($host) > 2 && substr($host, 0, 1) === '[' && substr($host, -1, 1) === ']') {
            return filter_var(substr($host, 1, -1), FILTER_VALIDATE_IP, FILTER_FLAG_IPV6) !== false;
        }
        //If removing all the dots results in a numeric string, it must be an IPv4 address.
        //Need to check this first because otherwise things like `999.0.0.0` are considered valid host names
        if (is_numeric(str_replace('.', '', $host))) {
            //Is it a valid IPv4 address?
            return filter_var($host, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4) !== false;
        }
        if (filter_var('http://' . $host, FILTER_VALIDATE_URL) !== false) {
            //Is it a syntactically valid hostname?
            return true;
        }
 
        return false;
    }
 
    protected function lang($key)
    {
        if (count($this->language) < 1) {
            $this->setLanguage(); // set the default language
        }
 
        if (array_key_exists($key, $this->language)) {
            if ('smtp_connect_failed' === $key) {
                //Include a link to troubleshooting docs on SMTP connection failure
                //this is by far the biggest cause of support questions
                //but it's usually not PHPMailer's fault.
                return $this->language[$key] . ' https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting';
            }
 
            return $this->language[$key];
        }
 
        //Return the key as a fallback
        return $key;
    }
 
    public function isError()
    {
        return $this->error_count > 0;
    }
 
    public function addCustomHeader($name, $value = null)
    {
        if (null === $value && strpos($name, ':') !== false) {
            // Value passed in as name:value
            list($name, $value) = explode(':', $name, 2);
        }
        $name = trim($name);
        $value = trim($value);
        //Ensure name is not empty, and that neither name nor value contain line breaks
        if (empty($name) || strpbrk($name . $value, "\r\n") !== false) {
            if ($this->exceptions) {
                throw new Exception('Invalid header name or value');
            }
 
            return false;
        }
        $this->CustomHeader[] = [$name, $value];
 
        return true;
    }
 
    public function getCustomHeaders()
    {
        return $this->CustomHeader;
    }
 
    public function msgHTML($message, $basedir = '', $advanced = false)
    {
        preg_match_all('/(?<!-)(src|background)=["\'](.*)["\']/Ui', $message, $images);
        if (array_key_exists(2, $images)) {
            if (strlen($basedir) > 1 && '/' !== substr($basedir, -1)) {
                // Ensure $basedir has a trailing /
                $basedir .= '/';
            }
            foreach ($images[2] as $imgindex => $url) {
                // Convert data URIs into embedded images
                //e.g. "data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw=="
                $match = [];
                if (preg_match('#^data:(image/(?:jpe?g|gif|png));?(base64)?,(.+)#', $url, $match)) {
                    if (count($match) === 4 && static::ENCODING_BASE64 === $match[2]) {
                        $data = base64_decode($match[3]);
                    } elseif ('' === $match[2]) {
                        $data = rawurldecode($match[3]);
                    } else {
                        //Not recognised so leave it alone
                        continue;
                    }
                    //Hash the decoded data, not the URL, so that the same data-URI image used in multiple places
                    //will only be embedded once, even if it used a different encoding
                    $cid = substr(hash('sha256', $data), 0, 32) . '@phpmailer.0'; // RFC2392 S 2
 
                    if (!$this->cidExists($cid)) {
                        $this->addStringEmbeddedImage(
                            $data,
                            $cid,
                            'embed' . $imgindex,
                            static::ENCODING_BASE64,
                            $match[1]
                        );
                    }
                    $message = str_replace(
                        $images[0][$imgindex],
                        $images[1][$imgindex] . '="cid:' . $cid . '"',
                        $message
                    );
                    continue;
                }
                if (// Only process relative URLs if a basedir is provided (i.e. no absolute local paths)
                    !empty($basedir)
                    // Ignore URLs containing parent dir traversal (..)
                    && (strpos($url, '..') === false)
                    // Do not change urls that are already inline images
                    && 0 !== strpos($url, 'cid:')
                    // Do not change absolute URLs, including anonymous protocol
                    && !preg_match('#^[a-z][a-z0-9+.-]*:?//#i', $url)
                ) {
                    $filename = static::mb_pathinfo($url, PATHINFO_BASENAME);
                    $directory = dirname($url);
                    if ('.' === $directory) {
                        $directory = '';
                    }
                    // RFC2392 S 2
                    $cid = substr(hash('sha256', $url), 0, 32) . '@phpmailer.0';
                    if (strlen($basedir) > 1 && '/' !== substr($basedir, -1)) {
                        $basedir .= '/';
                    }
                    if (strlen($directory) > 1 && '/' !== substr($directory, -1)) {
                        $directory .= '/';
                    }
                    if ($this->addEmbeddedImage(
                        $basedir . $directory . $filename,
                        $cid,
                        $filename,
                        static::ENCODING_BASE64,
                        static::_mime_types((string) static::mb_pathinfo($filename, PATHINFO_EXTENSION))
                    )
                    ) {
                        $message = preg_replace(
                            '/' . $images[1][$imgindex] . '=["\']' . preg_quote($url, '/') . '["\']/Ui',
                            $images[1][$imgindex] . '="cid:' . $cid . '"',
                            $message
                        );
                    }
                }
            }
        }
        $this->isHTML();
        // Convert all message body line breaks to LE, makes quoted-printable encoding work much better
        $this->Body = static::normalizeBreaks($message);
        $this->AltBody = static::normalizeBreaks($this->html2text($message, $advanced));
        if (!$this->alternativeExists()) {
            $this->AltBody = 'This is an HTML-only message. To view it, activate HTML in your email application.'
                . static::$LE;
        }
 
        return $this->Body;
    }
 
    public function html2text($html, $advanced = false)
    {
        if (is_callable($advanced)) {
            return $advanced($html);
        }
 
        return html_entity_decode(
            trim(strip_tags(preg_replace('/<(head|title|style|script)[^>]*>.*?<\/\\1>/si', '', $html))),
            ENT_QUOTES,
            $this->CharSet
        );
    }
 
    public static function _mime_types($ext = '')
    {
        $mimes = [
            'xl' => 'application/excel',
            'js' => 'application/javascript',
            'hqx' => 'application/mac-binhex40',
            'cpt' => 'application/mac-compactpro',
            'bin' => 'application/macbinary',
            'doc' => 'application/msword',
            'word' => 'application/msword',
            'xlsx' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
            'xltx' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.template',
            'potx' => 'application/vnd.openxmlformats-officedocument.presentationml.template',
            'ppsx' => 'application/vnd.openxmlformats-officedocument.presentationml.slideshow',
            'pptx' => 'application/vnd.openxmlformats-officedocument.presentationml.presentation',
            'sldx' => 'application/vnd.openxmlformats-officedocument.presentationml.slide',
            'docx' => 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
            'dotx' => 'application/vnd.openxmlformats-officedocument.wordprocessingml.template',
            'xlam' => 'application/vnd.ms-excel.addin.macroEnabled.12',
            'xlsb' => 'application/vnd.ms-excel.sheet.binary.macroEnabled.12',
            'class' => 'application/octet-stream',
            'dll' => 'application/octet-stream',
            'dms' => 'application/octet-stream',
            'exe' => 'application/octet-stream',
            'lha' => 'application/octet-stream',
            'lzh' => 'application/octet-stream',
            'psd' => 'application/octet-stream',
            'sea' => 'application/octet-stream',
            'so' => 'application/octet-stream',
            'oda' => 'application/oda',
            'pdf' => 'application/pdf',
            'ai' => 'application/postscript',
            'eps' => 'application/postscript',
            'ps' => 'application/postscript',
            'smi' => 'application/smil',
            'smil' => 'application/smil',
            'mif' => 'application/vnd.mif',
            'xls' => 'application/vnd.ms-excel',
            'ppt' => 'application/vnd.ms-powerpoint',
            'wbxml' => 'application/vnd.wap.wbxml',
            'wmlc' => 'application/vnd.wap.wmlc',
            'dcr' => 'application/x-director',
            'dir' => 'application/x-director',
            'dxr' => 'application/x-director',
            'dvi' => 'application/x-dvi',
            'gtar' => 'application/x-gtar',
            'php3' => 'application/x-httpd-php',
            'php4' => 'application/x-httpd-php',
            'php' => 'application/x-httpd-php',
            'phtml' => 'application/x-httpd-php',
            'phps' => 'application/x-httpd-php-source',
            'swf' => 'application/x-shockwave-flash',
            'sit' => 'application/x-stuffit',
            'tar' => 'application/x-tar',
            'tgz' => 'application/x-tar',
            'xht' => 'application/xhtml+xml',
            'xhtml' => 'application/xhtml+xml',
            'zip' => 'application/zip',
            'mid' => 'audio/midi',
            'midi' => 'audio/midi',
            'mp2' => 'audio/mpeg',
            'mp3' => 'audio/mpeg',
            'm4a' => 'audio/mp4',
            'mpga' => 'audio/mpeg',
            'aif' => 'audio/x-aiff',
            'aifc' => 'audio/x-aiff',
            'aiff' => 'audio/x-aiff',
            'ram' => 'audio/x-pn-realaudio',
            'rm' => 'audio/x-pn-realaudio',
            'rpm' => 'audio/x-pn-realaudio-plugin',
            'ra' => 'audio/x-realaudio',
            'wav' => 'audio/x-wav',
            'mka' => 'audio/x-matroska',
            'bmp' => 'image/bmp',
            'gif' => 'image/gif',
            'jpeg' => 'image/jpeg',
            'jpe' => 'image/jpeg',
            'jpg' => 'image/jpeg',
            'png' => 'image/png',
            'tiff' => 'image/tiff',
            'tif' => 'image/tiff',
            'webp' => 'image/webp',
            'heif' => 'image/heif',
            'heifs' => 'image/heif-sequence',
            'heic' => 'image/heic',
            'heics' => 'image/heic-sequence',
            'eml' => 'message/rfc822',
            'css' => 'text/css',
            'html' => 'text/html',
            'htm' => 'text/html',
            'shtml' => 'text/html',
            'log' => 'text/plain',
            'text' => 'text/plain',
            'txt' => 'text/plain',
            'rtx' => 'text/richtext',
            'rtf' => 'text/rtf',
            'vcf' => 'text/vcard',
            'vcard' => 'text/vcard',
            'ics' => 'text/calendar',
            'xml' => 'text/xml',
            'xsl' => 'text/xml',
            'wmv' => 'video/x-ms-wmv',
            'mpeg' => 'video/mpeg',
            'mpe' => 'video/mpeg',
            'mpg' => 'video/mpeg',
            'mp4' => 'video/mp4',
            'm4v' => 'video/mp4',
            'mov' => 'video/quicktime',
            'qt' => 'video/quicktime',
            'rv' => 'video/vnd.rn-realvideo',
            'avi' => 'video/x-msvideo',
            'movie' => 'video/x-sgi-movie',
            'webm' => 'video/webm',
            'mkv' => 'video/x-matroska',
        ];
        $ext = strtolower($ext);
        if (array_key_exists($ext, $mimes)) {
            return $mimes[$ext];
        }
 
        return 'application/octet-stream';
    }
 
    public static function filenameToType($filename)
    {
        // In case the path is a URL, strip any query string before getting extension
        $qpos = strpos($filename, '?');
        if (false !== $qpos) {
            $filename = substr($filename, 0, $qpos);
        }
        $ext = static::mb_pathinfo($filename, PATHINFO_EXTENSION);
 
        return static::_mime_types($ext);
    }
 
    public static function mb_pathinfo($path, $options = null)
    {
        $ret = ['dirname' => '', 'basename' => '', 'extension' => '', 'filename' => ''];
        $pathinfo = [];
        if (preg_match('#^(.*?)[\\\\/]*(([^/\\\\]*?)(\.([^.\\\\/]+?)|))[\\\\/.]*$#m', $path, $pathinfo)) {
            if (array_key_exists(1, $pathinfo)) {
                $ret['dirname'] = $pathinfo[1];
            }
            if (array_key_exists(2, $pathinfo)) {
                $ret['basename'] = $pathinfo[2];
            }
            if (array_key_exists(5, $pathinfo)) {
                $ret['extension'] = $pathinfo[5];
            }
            if (array_key_exists(3, $pathinfo)) {
                $ret['filename'] = $pathinfo[3];
            }
        }
        switch ($options) {
            case PATHINFO_DIRNAME:
            case 'dirname':
                return $ret['dirname'];
            case PATHINFO_BASENAME:
            case 'basename':
                return $ret['basename'];
            case PATHINFO_EXTENSION:
            case 'extension':
                return $ret['extension'];
            case PATHINFO_FILENAME:
            case 'filename':
                return $ret['filename'];
            default:
                return $ret;
        }
    }
 
    public function set($name, $value = '')
    {
        if (property_exists($this, $name)) {
            $this->$name = $value;
 
            return true;
        }
        $this->setError($this->lang('variable_set') . $name);
 
        return false;
    }
 
    public function secureHeader($str)
    {
        return trim(str_replace(["\r", "\n"], '', $str));
    }
 
    public static function normalizeBreaks($text, $breaktype = null)
    {
        if (null === $breaktype) {
            $breaktype = static::$LE;
        }
        // Normalise to \n
        $text = str_replace([self::CRLF, "\r"], "\n", $text);
        // Now convert LE as needed
        if ("\n" !== $breaktype) {
            $text = str_replace("\n", $breaktype, $text);
        }
 
        return $text;
    }
 
    public static function stripTrailingWSP($text)
    {
        return rtrim($text, " \r\n\t");
    }
 
    public static function getLE()
    {
        return static::$LE;
    }
 
    protected static function setLE($le)
    {
        static::$LE = $le;
    }
 
    public function sign($cert_filename, $key_filename, $key_pass, $extracerts_filename = '')
    {
        $this->sign_cert_file = $cert_filename;
        $this->sign_key_file = $key_filename;
        $this->sign_key_pass = $key_pass;
        $this->sign_extracerts_file = $extracerts_filename;
    }
 
    public function DKIM_QP($txt)
    {
        $line = '';
        $len = strlen($txt);
        for ($i = 0; $i < $len; ++$i) {
            $ord = ord($txt[$i]);
            if (((0x21 <= $ord) && ($ord <= 0x3A)) || $ord === 0x3C || ((0x3E <= $ord) && ($ord <= 0x7E))) {
                $line .= $txt[$i];
            } else {
                $line .= '=' . sprintf('%02X', $ord);
            }
        }
 
        return $line;
    }
 
    public function DKIM_Sign($signHeader)
    {
        if (!defined('PKCS7_TEXT')) {
            if ($this->exceptions) {
                throw new Exception($this->lang('extension_missing') . 'openssl');
            }
 
            return '';
        }
        $privKeyStr = !empty($this->DKIM_private_string) ?
            $this->DKIM_private_string :
            file_get_contents($this->DKIM_private);
        if ('' !== $this->DKIM_passphrase) {
            $privKey = openssl_pkey_get_private($privKeyStr, $this->DKIM_passphrase);
        } else {
            $privKey = openssl_pkey_get_private($privKeyStr);
        }
        if (openssl_sign($signHeader, $signature, $privKey, 'sha256WithRSAEncryption')) {
            openssl_pkey_free($privKey);
 
            return base64_encode($signature);
        }
        openssl_pkey_free($privKey);
 
        return '';
    }
 
    public function DKIM_HeaderC($signHeader)
    {
        //Normalize breaks to CRLF (regardless of the mailer)
        $signHeader = static::normalizeBreaks($signHeader, self::CRLF);
        //Unfold header lines
        //Note PCRE \s is too broad a definition of whitespace; RFC5322 defines it as `[ \t]`
        //@see https://tools.ietf.org/html/rfc5322#section-2.2
        //That means this may break if you do something daft like put vertical tabs in your headers.
        $signHeader = preg_replace('/\r\n[ \t]+/', ' ', $signHeader);
        //Break headers out into an array
        $lines = explode(self::CRLF, $signHeader);
        foreach ($lines as $key => $line) {
            //If the header is missing a :, skip it as it's invalid
            //This is likely to happen because the explode() above will also split
            //on the trailing LE, leaving an empty line
            if (strpos($line, ':') === false) {
                continue;
            }
            list($heading, $value) = explode(':', $line, 2);
            //Lower-case header name
            $heading = strtolower($heading);
            //Collapse white space within the value, also convert WSP to space
            $value = preg_replace('/[ \t]+/', ' ', $value);
            //RFC6376 is slightly unclear here - it says to delete space at the *end* of each value
            //But then says to delete space before and after the colon.
            //Net result is the same as trimming both ends of the value.
            //By elimination, the same applies to the field name
            $lines[$key] = trim($heading, " \t") . ':' . trim($value, " \t");
        }
 
        return implode(self::CRLF, $lines);
    }
 
    public function DKIM_BodyC($body)
    {
        if (empty($body)) {
            return self::CRLF;
        }
        // Normalize line endings to CRLF
        $body = static::normalizeBreaks($body, self::CRLF);
 
        //Reduce multiple trailing line breaks to a single one
        return static::stripTrailingWSP($body) . self::CRLF;
    }
 
    public function DKIM_Add($headers_line, $subject, $body)
    {
        $DKIMsignatureType = 'rsa-sha256'; // Signature & hash algorithms
        $DKIMcanonicalization = 'relaxed/simple'; // Canonicalization methods of header & body
        $DKIMquery = 'dns/txt'; // Query method
        $DKIMtime = time();
        //Always sign these headers without being asked
        //Recommended list from https://tools.ietf.org/html/rfc6376#section-5.4.1
        $autoSignHeaders = [
            'from',
            'to',
            'cc',
            'date',
            'subject',
            'reply-to',
            'message-id',
            'content-type',
            'mime-version',
            'x-mailer',
        ];
        if (stripos($headers_line, 'Subject') === false) {
            $headers_line .= 'Subject: ' . $subject . static::$LE;
        }
        $headerLines = explode(static::$LE, $headers_line);
        $currentHeaderLabel = '';
        $currentHeaderValue = '';
        $parsedHeaders = [];
        $headerLineIndex = 0;
        $headerLineCount = count($headerLines);
        foreach ($headerLines as $headerLine) {
            $matches = [];
            if (preg_match('/^([^ \t]*?)(?::[ \t]*)(.*)$/', $headerLine, $matches)) {
                if ($currentHeaderLabel !== '') {
                    //We were previously in another header; This is the start of a new header, so save the previous one
                    $parsedHeaders[] = ['label' => $currentHeaderLabel, 'value' => $currentHeaderValue];
                }
                $currentHeaderLabel = $matches[1];
                $currentHeaderValue = $matches[2];
            } elseif (preg_match('/^[ \t]+(.*)$/', $headerLine, $matches)) {
                //This is a folded continuation of the current header, so unfold it
                $currentHeaderValue .= ' ' . $matches[1];
            }
            ++$headerLineIndex;
            if ($headerLineIndex >= $headerLineCount) {
                //This was the last line, so finish off this header
                $parsedHeaders[] = ['label' => $currentHeaderLabel, 'value' => $currentHeaderValue];
            }
        }
        $copiedHeaders = [];
        $headersToSignKeys = [];
        $headersToSign = [];
        foreach ($parsedHeaders as $header) {
            //Is this header one that must be included in the DKIM signature?
            if (in_array(strtolower($header['label']), $autoSignHeaders, true)) {
                $headersToSignKeys[] = $header['label'];
                $headersToSign[] = $header['label'] . ': ' . $header['value'];
                if ($this->DKIM_copyHeaderFields) {
                    $copiedHeaders[] = $header['label'] . ':' . //Note no space after this, as per RFC
                        str_replace('|', '=7C', $this->DKIM_QP($header['value']));
                }
                continue;
            }
            //Is this an extra custom header we've been asked to sign?
            if (in_array($header['label'], $this->DKIM_extraHeaders, true)) {
                //Find its value in custom headers
                foreach ($this->CustomHeader as $customHeader) {
                    if ($customHeader[0] === $header['label']) {
                        $headersToSignKeys[] = $header['label'];
                        $headersToSign[] = $header['label'] . ': ' . $header['value'];
                        if ($this->DKIM_copyHeaderFields) {
                            $copiedHeaders[] = $header['label'] . ':' . //Note no space after this, as per RFC
                                str_replace('|', '=7C', $this->DKIM_QP($header['value']));
                        }
                        //Skip straight to the next header
                        continue 2;
                    }
                }
            }
        }
        $copiedHeaderFields = '';
        if ($this->DKIM_copyHeaderFields && count($copiedHeaders) > 0) {
            //Assemble a DKIM 'z' tag
            $copiedHeaderFields = ' z=';
            $first = true;
            foreach ($copiedHeaders as $copiedHeader) {
                if (!$first) {
                    $copiedHeaderFields .= static::$LE . ' |';
                }
                //Fold long values
                if (strlen($copiedHeader) > self::STD_LINE_LENGTH - 3) {
                    $copiedHeaderFields .= substr(
                        chunk_split($copiedHeader, self::STD_LINE_LENGTH - 3, static::$LE . self::FWS),
                        0,
                        -strlen(static::$LE . self::FWS)
                    );
                } else {
                    $copiedHeaderFields .= $copiedHeader;
                }
                $first = false;
            }
            $copiedHeaderFields .= ';' . static::$LE;
        }
        $headerKeys = ' h=' . implode(':', $headersToSignKeys) . ';' . static::$LE;
        $headerValues = implode(static::$LE, $headersToSign);
        $body = $this->DKIM_BodyC($body);
        $DKIMb64 = base64_encode(pack('H*', hash('sha256', $body))); // Base64 of packed binary SHA-256 hash of body
        $ident = '';
        if ('' !== $this->DKIM_identity) {
            $ident = ' i=' . $this->DKIM_identity . ';' . static::$LE;
        }
        //The DKIM-Signature header is included in the signature *except for* the value of the `b` tag
        //which is appended after calculating the signature
        //https://tools.ietf.org/html/rfc6376#section-3.5
        $dkimSignatureHeader = 'DKIM-Signature: v=1;' .
            ' d=' . $this->DKIM_domain . ';' .
            ' s=' . $this->DKIM_selector . ';' . static::$LE .
            ' a=' . $DKIMsignatureType . ';' .
            ' q=' . $DKIMquery . ';' .
            ' t=' . $DKIMtime . ';' .
            ' c=' . $DKIMcanonicalization . ';' . static::$LE .
            $headerKeys .
            $ident .
            $copiedHeaderFields .
            ' bh=' . $DKIMb64 . ';' . static::$LE .
            ' b=';
        //Canonicalize the set of headers
        $canonicalizedHeaders = $this->DKIM_HeaderC(
            $headerValues . static::$LE . $dkimSignatureHeader
        );
        $signature = $this->DKIM_Sign($canonicalizedHeaders);
        $signature = trim(chunk_split($signature, self::STD_LINE_LENGTH - 3, static::$LE . self::FWS));
 
        return static::normalizeBreaks($dkimSignatureHeader . $signature);
    }
 
    public static function hasLineLongerThanMax($str)
    {
        return (bool) preg_match('/^(.{' . (self::MAX_LINE_LENGTH + strlen(static::$LE)) . ',})/m', $str);
    }
 
    public static function quotedString($str)
    {
        if (preg_match('/[ ()<>@,;:"\/\[\]?=]/', $str)) {
            //If the string contains any of these chars, it must be double-quoted
            //and any double quotes must be escaped with a backslash
            return '"' . str_replace('"', '\\"', $str) . '"';
        }
 
        //Return the string untouched, it doesn't need quoting
        return $str;
    }
 
    public function getToAddresses()
    {
        return $this->to;
    }
 
    public function getCcAddresses()
    {
        return $this->cc;
    }
 
    public function getBccAddresses()
    {
        return $this->bcc;
    }
 
    public function getReplyToAddresses()
    {
        return $this->ReplyTo;
    }
 
    public function getAllRecipientAddresses()
    {
        return $this->all_recipients;
    }
 
    protected function doCallback($isSent, $to, $cc, $bcc, $subject, $body, $from, $extra)
    {
        if (!empty($this->action_function) && is_callable($this->action_function)) {
            call_user_func($this->action_function, $isSent, $to, $cc, $bcc, $subject, $body, $from, $extra);
        }
    }
 
    public function getOAuth()
    {
        return $this->oauth;
    }
 
    public function setOAuth(OAuth $oauth)
    {
        $this->oauth = $oauth;
    }
}