Merge branch 'bump-phpmailer' of Ezwen/ttrss-mailer-smtp into master

author: fox <[email protected]> 2020-04-29 16:50:47 +0000
committer: Gogs <[email protected]> 2020-04-29 16:50:47 +0000
commit: 1f9daa1b78be226505949e32984e3b167c4963a5 (patch)
tree: 40e84845476cd300a824a9779df673defdff25af
parent: eebc18f00ef5fbaebd4f9a6e43685f87ba8b537f (diff)
parent: bfc890882441e5990a2cba005228d52ff70098b3 (diff)
7 files changed, 963 insertions, 594 deletions
diff --git a/vendor/PHPMailer/PHPMailer/Exception.php b/vendor/PHPMailer/PHPMailer/Exception.php
index 9a05dec..b1e552f 100644
--- a/vendor/PHPMailer/PHPMailer/Exception.php
+++ b/vendor/PHPMailer/PHPMailer/Exception.php
@@ -23,7 +23,7 @@ namespace PHPMailer\PHPMailer;
 /**
  * PHPMailer exception handler.
  *
- * @author  Marcus Bointon <[email protected]>
+ * @author Marcus Bointon <[email protected]>
  */
 class Exception extends \Exception
 {
diff --git a/vendor/PHPMailer/PHPMailer/OAuth.php b/vendor/PHPMailer/PHPMailer/OAuth.php
index 0bce7e3..0271963 100644
--- a/vendor/PHPMailer/PHPMailer/OAuth.php
+++ b/vendor/PHPMailer/PHPMailer/OAuth.php
@@ -123,7 +123,7 @@ class OAuth
     public function getOauth64()
     {
         // Get a new token if it's not available or has expired
-        if (null === $this->oauthToken or $this->oauthToken->hasExpired()) {
+        if (null === $this->oauthToken || $this->oauthToken->hasExpired()) {
             $this->oauthToken = $this->getToken();
         }
 
diff --git a/vendor/PHPMailer/PHPMailer/PHPMailer.php b/vendor/PHPMailer/PHPMailer/PHPMailer.php
index a3be338..51dff92 100644
--- a/vendor/PHPMailer/PHPMailer/PHPMailer.php
+++ b/vendor/PHPMailer/PHPMailer/PHPMailer.php
@@ -3,13 +3,13 @@
  * PHPMailer - PHP email creation and transport class.
  * PHP Version 5.5.
  *
- * @see       https://github.com/PHPMailer/PHPMailer/ The PHPMailer GitHub project
+ * @see https://github.com/PHPMailer/PHPMailer/ The PHPMailer GitHub project
  *
  * @author    Marcus Bointon (Synchro/coolbru) <[email protected]>
  * @author    Jim Jagielski (jimjag) <[email protected]>
  * @author    Andy Prevost (codeworxtech) <[email protected]>
  * @author    Brent R. Matzelle (original founder)
- * @copyright 2012 - 2017 Marcus Bointon
+ * @copyright 2012 - 2019 Marcus Bointon
  * @copyright 2010 - 2012 Jim Jagielski
  * @copyright 2004 - 2009 Andy Prevost
  * @license   http://www.gnu.org/copyleft/lesser.html GNU Lesser General Public License
@@ -23,13 +23,14 @@ namespace PHPMailer\PHPMailer;
 /**
  * PHPMailer - PHP email creation and transport class.
  *
- * @author  Marcus Bointon (Synchro/coolbru) <[email protected]>
- * @author  Jim Jagielski (jimjag) <[email protected]>
- * @author  Andy Prevost (codeworxtech) <[email protected]>
- * @author  Brent R. Matzelle (original founder)
+ * @author Marcus Bointon (Synchro/coolbru) <[email protected]>
+ * @author Jim Jagielski (jimjag) <[email protected]>
+ * @author Andy Prevost (codeworxtech) <[email protected]>
+ * @author Brent R. Matzelle (original founder)
  */
 class PHPMailer
 {
+    const CHARSET_ASCII = 'us-ascii';
     const CHARSET_ISO88591 = 'iso-8859-1';
     const CHARSET_UTF8 = 'utf-8';
 
@@ -46,12 +47,24 @@ class PHPMailer
     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';
+
     /**
      * Email priority.
      * Options: null (default), 1 = High, 3 = Normal, 5 = low.
      * When null, the header is not set at all.
      *
-     * @var int
+     * @var int|null
      */
     public $Priority;
 
@@ -146,6 +159,22 @@ class PHPMailer
     public $Ical = '';
 
     /**
+     * Value-array of "method" in Contenttype header "text/calendar"
+     *
+     * @var string[]
+     */
+    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,
+    ];
+
+    /**
      * The complete compiled MIME message body.
      *
      * @var string
@@ -212,6 +241,8 @@ class PHPMailer
      * $_SERVER['SERVER_NAME'], gethostname(), php_uname('n'), or the value
      * 'localhost.localdomain'.
      *
+     * @see PHPMailer::$Helo
+     *
      * @var string
      */
     public $Hostname = '';
@@ -258,7 +289,7 @@ class PHPMailer
     public $Port = 25;
 
     /**
-     * The SMTP HELO of the message.
+     * The SMTP HELO/EHLO name used for the SMTP connection.
      * Default is $Hostname. If $Hostname is empty, PHPMailer attempts to find
      * one with the same method described above for $Hostname.
      *
@@ -270,7 +301,7 @@ class PHPMailer
 
     /**
      * What kind of encryption to use on the SMTP connection.
-     * Options: '', 'ssl' or 'tls'.
+     * Options: '', static::ENCRYPTION_STARTTLS, or static::ENCRYPTION_SMTPS.
      *
      * @var string
      */
@@ -341,14 +372,27 @@ class PHPMailer
     public $Timeout = 300;
 
     /**
+     * Comma separated list of DSN notifications
+     * 'NEVER' under no circumstances a DSN must be returned to the sender.
+     *         If you use NEVER all other notifications will be ignored.
+     * 'SUCCESS' will notify you when your mail has arrived at its destination.
+     * 'FAILURE' will arrive if an error occurred during delivery.
+     * 'DELAY'   will notify you if there is an unusual delay in delivery, but the actual
+     *           delivery's outcome (success or failure) is not yet decided.
+     *
+     * @see https://tools.ietf.org/html/rfc3461 See section 4.1 for more information about NOTIFY
+     */
+    public $dsn = '';
+
+    /**
      * SMTP class debug output mode.
      * Debug output level.
      * Options:
-     * * `0` No output
-     * * `1` Commands
-     * * `2` Data and commands
-     * * `3` As 2 plus connection status
-     * * `4` Low-level data output.
+     * * SMTP::DEBUG_OFF: No output
+     * * SMTP::DEBUG_CLIENT: Client messages
+     * * SMTP::DEBUG_SERVER: Client and server messages
+     * * SMTP::DEBUG_CONNECTION: As SERVER plus connection status
+     * * SMTP::DEBUG_LOWLEVEL: Noisy, low-level data output, rarely needed
      *
      * @see SMTP::$do_debug
      *
@@ -514,9 +558,9 @@ class PHPMailer
 
     /**
      * What to put in the X-Mailer header.
-     * Options: An empty string for PHPMailer default, whitespace for none, or a string to use.
+     * Options: An empty string for PHPMailer default, whitespace/null for none, or a string to use.
      *
-     * @var string
+     * @var string|null
      */
     public $XMailer = '';
 
@@ -701,7 +745,7 @@ class PHPMailer
      *
      * @var string
      */
-    const VERSION = '6.0.6';
+    const VERSION = '6.1.5';
 
     /**
      * Error severity: message only, continue processing.
@@ -725,11 +769,32 @@ class PHPMailer
     const STOP_CRITICAL = 2;
 
     /**
-     * SMTP RFC standard line ending.
+     * The SMTP standard CRLF line break.
+     * If you want to change line break format, change static::$LE, not this.
+     */
+    const CRLF = "\r\n";
+
+    /**
+     * "Folding White Space" a white space string used for line folding.
+     */
+    const FWS = ' ';
+
+    /**
+     * SMTP RFC standard line ending; Carriage Return, Line Feed.
      *
      * @var string
      */
-    protected static $LE = "\r\n";
+    protected static $LE = self::CRLF;
+
+    /**
+     * The maximum line length supported by mail().
+     *
+     * Background: mail() will sometimes corrupt messages
+     * with headers headers longer than 65 chars, see #818.
+     *
+     * @var int
+     */
+    const MAIL_MAX_LINE_LENGTH = 63;
 
     /**
      * The maximum line length allowed by RFC 2822 section 2.1.1.
@@ -794,7 +859,7 @@ class PHPMailer
             $subject = $this->encodeHeader($this->secureHeader($subject));
         }
         //Calling mail() with null params breaks
-        if (!$this->UseSendmailOptions or null === $params) {
+        if (!$this->UseSendmailOptions || null === $params) {
             $result = @mail($to, $subject, $body, $header);
         } else {
             $result = @mail($to, $subject, $body, $header, $params);
@@ -824,7 +889,7 @@ class PHPMailer
             return;
         }
         //Avoid clash with built-in function names
-        if (!in_array($this->Debugoutput, ['error_log', 'html', 'echo']) and is_callable($this->Debugoutput)) {
+        if (is_callable($this->Debugoutput) && !in_array($this->Debugoutput, ['error_log', 'html', 'echo'])) {
             call_user_func($this->Debugoutput, $str, $this->SMTPDebug);
 
             return;
@@ -845,12 +910,12 @@ class PHPMailer
             case 'echo':
             default:
                 //Normalize line breaks
-                $str = preg_replace('/\r\n|\r/ms', "\n", $str);
+                $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
+                    //Indent for readability, except for trailing break
                     str_replace(
                         "\n",
                         "\n                   \t                  ",
@@ -927,6 +992,8 @@ class PHPMailer
      * @param string $address The email address to send to
      * @param string $name
      *
+     * @throws Exception
+     *
      * @return bool true on success, false if address already used or invalid in some way
      */
     public function addAddress($address, $name = '')
@@ -940,6 +1007,8 @@ class PHPMailer
      * @param string $address The email address to send to
      * @param string $name
      *
+     * @throws Exception
+     *
      * @return bool true on success, false if address already used or invalid in some way
      */
     public function addCC($address, $name = '')
@@ -953,6 +1022,8 @@ class PHPMailer
      * @param string $address The email address to send to
      * @param string $name
      *
+     * @throws Exception
+     *
      * @return bool true on success, false if address already used or invalid in some way
      */
     public function addBCC($address, $name = '')
@@ -966,6 +1037,8 @@ class PHPMailer
      * @param string $address The email address to reply to
      * @param string $name
      *
+     * @throws Exception
+     *
      * @return bool true on success, false if address already used or invalid in some way
      */
     public function addReplyTo($address, $name = '')
@@ -994,10 +1067,12 @@ class PHPMailer
         $pos = strrpos($address, '@');
         if (false === $pos) {
             // At-sign is missing.
-            $error_message = sprintf('%s (%s): %s',
+            $error_message = sprintf(
+                '%s (%s): %s',
                 $this->lang('invalid_address'),
                 $kind,
-                $address);
+                $address
+            );
             $this->setError($error_message);
             $this->edebug($error_message);
             if ($this->exceptions) {
@@ -1008,19 +1083,17 @@ class PHPMailer
         }
         $params = [$kind, $address, $name];
         // Enqueue addresses with IDN until we know the PHPMailer::$CharSet.
-        if ($this->has8bitChars(substr($address, ++$pos)) and static::idnSupported()) {
-            if ('Reply-To' != $kind) {
+        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;
                 }
-            } else {
-                if (!array_key_exists($address, $this->ReplyToQueue)) {
-                    $this->ReplyToQueue[$address] = $params;
+            } elseif (!array_key_exists($address, $this->ReplyToQueue)) {
+                $this->ReplyToQueue[$address] = $params;
 
-                    return true;
-                }
+                return true;
             }
 
             return false;
@@ -1045,9 +1118,11 @@ class PHPMailer
     protected function addAnAddress($kind, $address, $name = '')
     {
         if (!in_array($kind, ['to', 'cc', 'bcc', 'Reply-To'])) {
-            $error_message = sprintf('%s: %s',
+            $error_message = sprintf(
+                '%s: %s',
                 $this->lang('Invalid recipient kind'),
-                $kind);
+                $kind
+            );
             $this->setError($error_message);
             $this->edebug($error_message);
             if ($this->exceptions) {
@@ -1057,10 +1132,12 @@ class PHPMailer
             return false;
         }
         if (!static::validateAddress($address)) {
-            $error_message = sprintf('%s (%s): %s',
+            $error_message = sprintf(
+                '%s (%s): %s',
                 $this->lang('invalid_address'),
                 $kind,
-                $address);
+                $address
+            );
             $this->setError($error_message);
             $this->edebug($error_message);
             if ($this->exceptions) {
@@ -1069,19 +1146,17 @@ class PHPMailer
 
             return false;
         }
-        if ('Reply-To' != $kind) {
+        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;
             }
-        } else {
-            if (!array_key_exists(strtolower($address), $this->ReplyTo)) {
-                $this->ReplyTo[strtolower($address)] = [$address, $name];
+        } elseif (!array_key_exists(strtolower($address), $this->ReplyTo)) {
+            $this->ReplyTo[strtolower($address)] = [$address, $name];
 
-                return true;
-            }
+            return true;
         }
 
         return false;
@@ -1093,7 +1168,7 @@ class PHPMailer
      * Uses the imap_rfc822_parse_adrlist function if the IMAP extension is available.
      * Note that quotes in the name part are removed.
      *
-     * @see    http://www.andrew.cmu.edu/user/agreen1/testing/mrbs/web/Mail/RFC822.php A more careful implementation
+     * @see http://www.andrew.cmu.edu/user/agreen1/testing/mrbs/web/Mail/RFC822.php A more careful implementation
      *
      * @param string $addrstr The address list string
      * @param bool   $useimap Whether to use the IMAP extension to parse the list
@@ -1103,17 +1178,17 @@ class PHPMailer
     public static function parseAddresses($addrstr, $useimap = true)
     {
         $addresses = [];
-        if ($useimap and function_exists('imap_rfc822_parse_adrlist')) {
+        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.' != $address->host) {
-                    if (static::validateAddress($address->mailbox . '@' . $address->host)) {
-                        $addresses[] = [
-                            'name' => (property_exists($address, 'personal') ? $address->personal : ''),
-                            'address' => $address->mailbox . '@' . $address->host,
-                        ];
-                    }
+                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 {
@@ -1163,12 +1238,15 @@ class PHPMailer
         $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 === $pos or
-            (!$this->has8bitChars(substr($address, ++$pos)) or !static::idnSupported()) and
-            !static::validateAddress($address)) {
-            $error_message = sprintf('%s (From): %s',
+        if ((false === $pos)
+            || ((!$this->has8bitChars(substr($address, ++$pos)) || !static::idnSupported())
+            && !static::validateAddress($address))
+        ) {
+            $error_message = sprintf(
+                '%s (From): %s',
                 $this->lang('invalid_address'),
-                $address);
+                $address
+            );
             $this->setError($error_message);
             $this->edebug($error_message);
             if ($this->exceptions) {
@@ -1179,10 +1257,8 @@ class PHPMailer
         }
         $this->From = $address;
         $this->FromName = $name;
-        if ($auto) {
-            if (empty($this->Sender)) {
-                $this->Sender = $address;
-            }
+        if ($auto && empty($this->Sender)) {
+            $this->Sender = $address;
         }
 
         return true;
@@ -1231,10 +1307,10 @@ class PHPMailer
             $patternselect = static::$validator;
         }
         if (is_callable($patternselect)) {
-            return call_user_func($patternselect, $address);
+            return $patternselect($address);
         }
         //Reject line breaks in addresses; it's valid RFC5322, but not RFC5321
-        if (strpos($address, "\n") !== false or strpos($address, "\r") !== false) {
+        if (strpos($address, "\n") !== false || strpos($address, "\r") !== false) {
             return false;
         }
         switch ($patternselect) {
@@ -1281,7 +1357,7 @@ class PHPMailer
                 );
             case 'php':
             default:
-                return (bool) filter_var($address, FILTER_VALIDATE_EMAIL);
+                return filter_var($address, FILTER_VALIDATE_EMAIL) !== false;
         }
     }
 
@@ -1293,7 +1369,7 @@ class PHPMailer
      */
     public static function idnSupported()
     {
-        return function_exists('idn_to_ascii') and function_exists('mb_convert_encoding');
+        return function_exists('idn_to_ascii') && function_exists('mb_convert_encoding');
     }
 
     /**
@@ -1304,7 +1380,7 @@ class PHPMailer
      * - Conversion to punycode is impossible (e.g. required PHP functions are not available)
      *   or fails for any reason (e.g. domain contains characters not allowed in an IDN).
      *
-     * @see    PHPMailer::$CharSet
+     * @see PHPMailer::$CharSet
      *
      * @param string $address The email address to convert
      *
@@ -1314,17 +1390,23 @@ class PHPMailer
     {
         // Verify we have required functions, CharSet, and at-sign.
         $pos = strrpos($address, '@');
-        if (static::idnSupported() and
-            !empty($this->CharSet) and
-            false !== $pos
+        if (!empty($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($domain) and @mb_check_encoding($domain, $this->CharSet)) {
+            if ($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;
-                $punycode = idn_to_ascii($domain, $errorcode, INTL_IDNA_VARIANT_UTS46);
+                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;
                 }
@@ -1370,24 +1452,22 @@ class PHPMailer
      */
     public function preSend()
     {
-        if ('smtp' == $this->Mailer or
-            ('mail' == $this->Mailer and stripos(PHP_OS, 'WIN') === 0)
+        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("\r\n");
+            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 (ini_get('mail.add_x_header') == 1
-            and 'mail' == $this->Mailer
-            and stripos(PHP_OS, 'WIN') === 0
-            and ((version_compare(PHP_VERSION, '7.0.0', '>=')
-                    and version_compare(PHP_VERSION, '7.0.17', '<'))
-                or (version_compare(PHP_VERSION, '7.1.0', '>=')
-                    and version_compare(PHP_VERSION, '7.1.3', '<')))
+        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.' .
@@ -1418,10 +1498,12 @@ class PHPMailer
                 }
                 $this->$address_kind = $this->punyencodeAddress($this->$address_kind);
                 if (!static::validateAddress($this->$address_kind)) {
-                    $error_message = sprintf('%s (%s): %s',
+                    $error_message = sprintf(
+                        '%s (%s): %s',
                         $this->lang('invalid_address'),
                         $address_kind,
-                        $this->$address_kind);
+                        $this->$address_kind
+                    );
                     $this->setError($error_message);
                     $this->edebug($error_message);
                     if ($this->exceptions) {
@@ -1439,7 +1521,7 @@ class PHPMailer
 
             $this->setMessageType();
             // Refuse to send an empty message unless we are specifically allowing it
-            if (!$this->AllowEmpty and empty($this->Body)) {
+            if (!$this->AllowEmpty && empty($this->Body)) {
                 throw new Exception($this->lang('empty_message'), self::STOP_CRITICAL);
             }
 
@@ -1455,7 +1537,7 @@ class PHPMailer
 
             // To capture the complete message when using mail(), create
             // an extra header list which createHeader() doesn't fold in
-            if ('mail' == $this->Mailer) {
+            if ('mail' === $this->Mailer) {
                 if (count($this->to) > 0) {
                     $this->mailHeader .= $this->addrAppend('To', $this->to);
                 } else {
@@ -1469,11 +1551,11 @@ class PHPMailer
 
             // Sign with DKIM if enabled
             if (!empty($this->DKIM_domain)
-                and !empty($this->DKIM_selector)
-                and (!empty($this->DKIM_private_string)
-                    or (!empty($this->DKIM_private)
-                        and static::isPermittedPath($this->DKIM_private)
-                        and file_exists($this->DKIM_private)
+                && !empty($this->DKIM_selector)
+                && (!empty($this->DKIM_private_string)
+                    || (!empty($this->DKIM_private)
+                        && static::isPermittedPath($this->DKIM_private)
+                        && file_exists($this->DKIM_private)
                     )
                 )
             ) {
@@ -1482,7 +1564,7 @@ class PHPMailer
                     $this->encodeHeader($this->secureHeader($this->Subject)),
                     $this->MIMEBody
                 );
-                $this->MIMEHeader = rtrim($this->MIMEHeader, "\r\n ") . static::$LE .
+                $this->MIMEHeader = static::stripTrailingWSP($this->MIMEHeader) . static::$LE .
                     static::normalizeBreaks($header_dkim) . static::$LE;
             }
 
@@ -1538,7 +1620,7 @@ class PHPMailer
     /**
      * Send mail using the $Sendmail program.
      *
-     * @see    PHPMailer::$Sendmail
+     * @see PHPMailer::$Sendmail
      *
      * @param string $header The message headers
      * @param string $body   The message body
@@ -1549,19 +1631,19 @@ class PHPMailer
      */
     protected function sendmailSend($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($this->Sender) and self::isShellSafe($this->Sender)) {
-            if ('qmail' == $this->Mailer) {
+        if (!empty($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 {
-            if ('qmail' == $this->Mailer) {
-                $sendmailFmt = '%s';
-            } else {
-                $sendmailFmt = '%s -oi -t';
-            }
+            $sendmailFmt = '%s -oi -t';
         }
 
         $sendmail = sprintf($sendmailFmt, escapeshellcmd($this->Sendmail), $this->Sender);
@@ -1577,7 +1659,7 @@ class PHPMailer
                 fwrite($mail, $body);
                 $result = pclose($mail);
                 $this->doCallback(
-                    ($result == 0),
+                    ($result === 0),
                     [$toAddr],
                     $this->cc,
                     $this->bcc,
@@ -1599,7 +1681,7 @@ class PHPMailer
             fwrite($mail, $body);
             $result = pclose($mail);
             $this->doCallback(
-                ($result == 0),
+                ($result === 0),
                 $this->to,
                 $this->cc,
                 $this->bcc,
@@ -1630,7 +1712,7 @@ class PHPMailer
     {
         // Future-proof
         if (escapeshellcmd($string) !== $string
-            or !in_array(escapeshellarg($string), ["'$string'", "\"$string\""])
+            || !in_array(escapeshellarg($string), ["'$string'", "\"$string\""])
         ) {
             return false;
         }
@@ -1668,7 +1750,7 @@ class PHPMailer
     /**
      * Send mail using the PHP mail() function.
      *
-     * @see    http://www.php.net/manual/en/book.mail.php
+     * @see http://www.php.net/manual/en/book.mail.php
      *
      * @param string $header The message headers
      * @param string $body   The message body
@@ -1679,6 +1761,8 @@ class PHPMailer
      */
     protected function mailSend($header, $body)
     {
+        $header = static::stripTrailingWSP($header) . static::$LE . static::$LE;
+
         $toArr = [];
         foreach ($this->to as $toaddr) {
             $toArr[] = $this->addrFormat($toaddr);
@@ -1687,24 +1771,22 @@ class PHPMailer
 
         $params = null;
         //This sets the SMTP envelope sender which gets turned into a return-path header by the receiver
-        if (!empty($this->Sender) and static::validateAddress($this->Sender)) {
-            //A space after `-f` is optional, but there is a long history of its presence
-            //causing problems, so we don't use one
-            //Exim docs: http://www.exim.org/exim-html-current/doc/html/spec_html/ch-the_exim_command_line.html
-            //Sendmail docs: http://www.sendmail.org/~ca/email/man/sendmail.html
-            //Qmail docs: http://www.qmail.org/man/man8/qmail-inject.html
-            //Example problem: https://www.drupal.org/node/1057954
-            // CVE-2016-10033, CVE-2016-10045: Don't pass -f if characters will be escaped.
-            if (self::isShellSafe($this->Sender)) {
-                $params = sprintf('-f%s', $this->Sender);
-            }
+        //A space after `-f` is optional, but there is a long history of its presence
+        //causing problems, so we don't use one
+        //Exim docs: http://www.exim.org/exim-html-current/doc/html/spec_html/ch-the_exim_command_line.html
+        //Sendmail docs: http://www.sendmail.org/~ca/email/man/sendmail.html
+        //Qmail docs: http://www.qmail.org/man/man8/qmail-inject.html
+        //Example problem: https://www.drupal.org/node/1057954
+        // CVE-2016-10033, CVE-2016-10045: Don't pass -f if characters will be escaped.
+        if (!empty($this->Sender) && static::validateAddress($this->Sender) && self::isShellSafe($this->Sender)) {
+            $params = sprintf('-f%s', $this->Sender);
         }
-        if (!empty($this->Sender) and static::validateAddress($this->Sender)) {
+        if (!empty($this->Sender) && static::validateAddress($this->Sender)) {
             $old_from = ini_get('sendmail_from');
             ini_set('sendmail_from', $this->Sender);
         }
         $result = false;
-        if ($this->SingleTo and count($toArr) > 1) {
+        if ($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, []);
@@ -1742,8 +1824,6 @@ class PHPMailer
     /**
      * Provide an instance to use for SMTP operations.
      *
-     * @param SMTP $smtp
-     *
      * @return SMTP
      */
     public function setSMTPInstance(SMTP $smtp)
@@ -1770,12 +1850,13 @@ class PHPMailer
      */
     protected function smtpSend($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) {
+        if ('' === $this->Sender) {
             $smtp_from = $this->From;
         } else {
             $smtp_from = $this->Sender;
@@ -1789,7 +1870,7 @@ class PHPMailer
         // Attempt to send to all recipients
         foreach ([$this->to, $this->cc, $this->bcc] as $togroup) {
             foreach ($togroup as $to) {
-                if (!$this->smtp->recipient($to[0])) {
+                if (!$this->smtp->recipient($to[0], $this->dsn)) {
                     $error = $this->smtp->getError();
                     $bad_rcpt[] = ['to' => $to[0], 'error' => $error['detail']];
                     $isSent = false;
@@ -1802,7 +1883,7 @@ class PHPMailer
         }
 
         // Only send the DATA command if we have viable recipients
-        if ((count($this->all_recipients) > count($bad_rcpt)) and !$this->smtp->data($header . $body)) {
+        if ((count($this->all_recipients) > count($bad_rcpt)) && !$this->smtp->data($header . $body)) {
             throw new Exception($this->lang('data_not_accepted'), self::STOP_CRITICAL);
         }
 
@@ -1834,10 +1915,7 @@ class PHPMailer
             foreach ($bad_rcpt as $bad) {
                 $errstr .= $bad['to'] . ': ' . $bad['error'];
             }
-            throw new Exception(
-                $this->lang('recipients_failed') . $errstr,
-                self::STOP_CONTINUE
-            );
+            throw new Exception($this->lang('recipients_failed') . $errstr, self::STOP_CONTINUE);
         }
 
         return true;
@@ -1881,50 +1959,49 @@ class PHPMailer
         foreach ($hosts as $hostentry) {
             $hostinfo = [];
             if (!preg_match(
-                '/^((ssl|tls):\/\/)*([a-zA-Z0-9\.-]*|\[[a-fA-F0-9:]+\]):?([0-9]*)$/',
+                '/^(?:(ssl|tls):\/\/)?(.+?)(?::(\d+))?$/',
                 trim($hostentry),
                 $hostinfo
             )) {
-                static::edebug($this->lang('connect_host') . ' ' . $hostentry);
+                $this->edebug($this->lang('invalid_hostentry') . ' ' . trim($hostentry));
                 // Not a valid host entry
                 continue;
             }
-            // $hostinfo[2]: optional ssl or tls prefix
-            // $hostinfo[3]: the hostname
-            // $hostinfo[4]: optional port number
+            // $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($hostinfo[3])) {
-                static::edebug($this->lang('connect_host') . ' ' . $hostentry);
+            if (!static::isValidHost($hostinfo[2])) {
+                $this->edebug($this->lang('invalid_host') . ' ' . $hostinfo[2]);
                 continue;
             }
             $prefix = '';
             $secure = $this->SMTPSecure;
-            $tls = ('tls' == $this->SMTPSecure);
-            if ('ssl' == $hostinfo[2] or ('' == $hostinfo[2] and 'ssl' == $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 = 'ssl';
-            } elseif ('tls' == $hostinfo[2]) {
+                $secure = static::ENCRYPTION_SMTPS;
+            } elseif ('tls' === $hostinfo[1]) {
                 $tls = true;
                 // tls doesn't use a prefix
-                $secure = 'tls';
+                $secure = static::ENCRYPTION_STARTTLS;
             }
             //Do we need the OpenSSL extension?
             $sslext = defined('OPENSSL_ALGO_SHA256');
-            if ('tls' === $secure or 'ssl' === $secure) {
+            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[3];
+            $host = $hostinfo[2];
             $port = $this->Port;
-            $tport = (int) $hostinfo[4];
-            if ($tport > 0 and $tport < 65536) {
-                $port = $tport;
+            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, $options)) {
                 try {
@@ -1939,7 +2016,7 @@ class PHPMailer
                     // * we have openssl extension
                     // * we are not already using SSL
                     // * the server offers STARTTLS
-                    if ($this->SMTPAutoTLS and $sslext and 'ssl' != $secure and $this->smtp->getServerExt('STARTTLS')) {
+                    if ($this->SMTPAutoTLS && $sslext && 'ssl' !== $secure && $this->smtp->getServerExt('STARTTLS')) {
                         $tls = true;
                     }
                     if ($tls) {
@@ -1949,16 +2026,13 @@ class PHPMailer
                         // We must resend EHLO after TLS negotiation
                         $this->smtp->hello($hello);
                     }
-                    if ($this->SMTPAuth) {
-                        if (!$this->smtp->authenticate(
-                            $this->Username,
-                            $this->Password,
-                            $this->AuthType,
-                            $this->oauth
-                        )
-                        ) {
-                            throw new Exception($this->lang('authenticate'));
-                        }
+                    if ($this->SMTPAuth && !$this->smtp->authenticate(
+                        $this->Username,
+                        $this->Password,
+                        $this->AuthType,
+                        $this->oauth
+                    )) {
+                        throw new Exception($this->lang('authenticate'));
                     }
 
                     return true;
@@ -1973,7 +2047,7 @@ class PHPMailer
         // 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 and null !== $lastexception) {
+        if ($this->exceptions && null !== $lastexception) {
             throw $lastexception;
         }
 
@@ -1985,11 +2059,9 @@ class PHPMailer
      */
     public function smtpClose()
     {
-        if (null !== $this->smtp) {
-            if ($this->smtp->connected()) {
-                $this->smtp->quit();
-                $this->smtp->close();
-            }
+        if ((null !== $this->smtp) && $this->smtp->connected()) {
+            $this->smtp->quit();
+            $this->smtp->close();
         }
     }
 
@@ -2014,6 +2086,7 @@ class PHPMailer
             'se' => 'sv',
             'rs' => 'sr',
             'tg' => 'tl',
+            'am' => 'hy',
         ];
 
         if (isset($renamed_langcodes[$langcode])) {
@@ -2033,6 +2106,8 @@ class PHPMailer
             '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: ',
@@ -2053,7 +2128,7 @@ class PHPMailer
         $foundlang = true;
         $lang_file = $lang_path . 'phpmailer.lang-' . $langcode . '.php';
         // There is no English translation file
-        if ('en' != $langcode) {
+        if ('en' !== $langcode) {
             // Make sure language file path is readable
             if (!static::isPermittedPath($lang_file) || !file_exists($lang_file)) {
                 $foundlang = false;
@@ -2113,9 +2188,8 @@ class PHPMailer
             return $this->secureHeader($addr[0]);
         }
 
-        return $this->encodeHeader($this->secureHeader($addr[1]), 'phrase') . ' <' . $this->secureHeader(
-                $addr[0]
-            ) . '>';
+        return $this->encodeHeader($this->secureHeader($addr[1]), 'phrase') .
+            ' <' . $this->secureHeader($addr[0]) . '>';
     }
 
     /**
@@ -2145,7 +2219,7 @@ class PHPMailer
 
         $message = static::normalizeBreaks($message);
         //Remove a trailing line break
-        if (substr($message, -$lelen) == static::$LE) {
+        if (substr($message, -$lelen) === static::$LE) {
             $message = substr($message, 0, -$lelen);
         }
 
@@ -2158,16 +2232,16 @@ class PHPMailer
             $buf = '';
             $firstword = true;
             foreach ($words as $word) {
-                if ($qp_mode and (strlen($word) > $length)) {
+                if ($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, $len - 1, 1)) {
+                            } elseif ('=' === substr($word, $len - 1, 1)) {
                                 --$len;
-                            } elseif ('=' == substr($word, $len - 2, 1)) {
+                            } elseif ('=' === substr($word, $len - 2, 1)) {
                                 $len -= 2;
                             }
                             $part = substr($word, 0, $len);
@@ -2179,22 +2253,22 @@ class PHPMailer
                         }
                         $buf = '';
                     }
-                    while (strlen($word) > 0) {
+                    while ($word !== '') {
                         if ($length <= 0) {
                             break;
                         }
                         $len = $length;
                         if ($is_utf8) {
                             $len = $this->utf8CharBoundary($word, $len);
-                        } elseif ('=' == substr($word, $len - 1, 1)) {
+                        } elseif ('=' === substr($word, $len - 1, 1)) {
                             --$len;
-                        } elseif ('=' == substr($word, $len - 2, 1)) {
+                        } elseif ('=' === substr($word, $len - 2, 1)) {
                             $len -= 2;
                         }
                         $part = substr($word, 0, $len);
-                        $word = substr($word, $len);
+                        $word = (string) substr($word, $len);
 
-                        if (strlen($word) > 0) {
+                        if ($word !== '') {
                             $message .= $part . sprintf('=%s', static::$LE);
                         } else {
                             $buf = $part;
@@ -2207,7 +2281,7 @@ class PHPMailer
                     }
                     $buf .= $word;
 
-                    if (strlen($buf) > $length and '' != $buf_o) {
+                    if ('' !== $buf_o && strlen($buf) > $length) {
                         $message .= $buf_o . $soft_break;
                         $buf = $word;
                     }
@@ -2302,23 +2376,21 @@ class PHPMailer
     {
         $result = '';
 
-        $result .= $this->headerLine('Date', '' == $this->MessageDate ? self::rfcDate() : $this->MessageDate);
+        $result .= $this->headerLine('Date', '' === $this->MessageDate ? self::rfcDate() : $this->MessageDate);
 
         // To be created automatically by mail()
         if ($this->SingleTo) {
-            if ('mail' != $this->Mailer) {
+            if ('mail' !== $this->Mailer) {
                 foreach ($this->to as $toaddr) {
                     $this->SingleToArray[] = $this->addrFormat($toaddr);
                 }
             }
-        } else {
-            if (count($this->to) > 0) {
-                if ('mail' != $this->Mailer) {
-                    $result .= $this->addrAppend('To', $this->to);
-                }
-            } elseif (count($this->cc) == 0) {
-                $result .= $this->headerLine('To', 'undisclosed-recipients:;');
+        } elseif (count($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]]);
@@ -2330,9 +2402,9 @@ class PHPMailer
 
         // sendmail and mail() extract Bcc from the header before sending
         if ((
-                'sendmail' == $this->Mailer or 'qmail' == $this->Mailer or 'mail' == $this->Mailer
+                'sendmail' === $this->Mailer || 'qmail' === $this->Mailer || 'mail' === $this->Mailer
             )
-            and count($this->bcc) > 0
+            && count($this->bcc) > 0
         ) {
             $result .= $this->addrAppend('Bcc', $this->bcc);
         }
@@ -2342,13 +2414,13 @@ class PHPMailer
         }
 
         // mail() sets the subject itself
-        if ('mail' != $this->Mailer) {
+        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 ('' != $this->MessageID and preg_match('/^<.*@.*>$/', $this->MessageID)) {
+        if ('' !== $this->MessageID && preg_match('/^<.*@.*>$/', $this->MessageID)) {
             $this->lastMessageID = $this->MessageID;
         } else {
             $this->lastMessageID = sprintf('<%s@%s>', $this->uniqueid, $this->serverHostname());
@@ -2357,7 +2429,7 @@ class PHPMailer
         if (null !== $this->Priority) {
             $result .= $this->headerLine('X-Priority', $this->Priority);
         }
-        if ('' == $this->XMailer) {
+        if ('' === $this->XMailer) {
             $result .= $this->headerLine(
                 'X-Mailer',
                 'PHPMailer ' . self::VERSION . ' (https://github.com/PHPMailer/PHPMailer)'
@@ -2369,7 +2441,7 @@ class PHPMailer
             }
         }
 
-        if ('' != $this->ConfirmReadingTo) {
+        if ('' !== $this->ConfirmReadingTo) {
             $result .= $this->headerLine('Disposition-Notification-To', '<' . $this->ConfirmReadingTo . '>');
         }
 
@@ -2400,19 +2472,19 @@ class PHPMailer
         switch ($this->message_type) {
             case 'inline':
                 $result .= $this->headerLine('Content-Type', static::CONTENT_TYPE_MULTIPART_RELATED . ';');
-                $result .= $this->textLine("\tboundary=\"" . $this->boundary[1] . '"');
+                $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("\tboundary=\"" . $this->boundary[1] . '"');
+                $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("\tboundary=\"" . $this->boundary[1] . '"');
+                $result .= $this->textLine(' boundary="' . $this->boundary[1] . '"');
                 break;
             default:
                 // Catches case 'plain': and case '':
@@ -2421,10 +2493,10 @@ class PHPMailer
                 break;
         }
         // RFC1341 part 5 says 7bit is assumed if not specified
-        if (static::ENCODING_7BIT != $this->Encoding) {
+        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) {
+                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
@@ -2433,8 +2505,8 @@ class PHPMailer
             }
         }
 
-        if ('mail' != $this->Mailer) {
-            $result .= static::$LE;
+        if ('mail' !== $this->Mailer) {
+//            $result .= static::$LE;
         }
 
         return $result;
@@ -2451,7 +2523,8 @@ class PHPMailer
      */
     public function getSentMIMEMessage()
     {
-        return rtrim($this->MIMEHeader . $this->mailHeader, "\n\r") . static::$LE . static::$LE . $this->MIMEBody;
+        return static::stripTrailingWSP($this->MIMEHeader . $this->mailHeader) .
+            static::$LE . static::$LE . $this->MIMEBody;
     }
 
     /**
@@ -2462,11 +2535,19 @@ class PHPMailer
     protected function generateId()
     {
         $len = 32; //32 bytes = 256 bits
+        $bytes = '';
         if (function_exists('random_bytes')) {
-            $bytes = random_bytes($len);
+            try {
+                $bytes = random_bytes($len);
+            } catch (\Exception $e) {
+                //Do nothing
+            }
         } elseif (function_exists('openssl_random_pseudo_bytes')) {
+            /** @noinspection CryptographicallySecureRandomnessInspection */
             $bytes = openssl_random_pseudo_bytes($len);
-        } else {
+        }
+        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);
         }
@@ -2501,32 +2582,32 @@ class PHPMailer
         $bodyEncoding = $this->Encoding;
         $bodyCharSet = $this->CharSet;
         //Can we do a 7-bit downgrade?
-        if (static::ENCODING_8BIT == $bodyEncoding and !$this->has8bitChars($this->Body)) {
+        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 = 'us-ascii';
+            $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 != $this->Encoding and static::hasLineLongerThanMax($this->Body)) {
+        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 == $altBodyEncoding and !$this->has8bitChars($this->AltBody)) {
+        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 = 'us-ascii';
+            $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 != $altBodyEncoding and static::hasLineLongerThanMax($this->AltBody)) {
+        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;
+        $mimepre = 'This is a multi-part message in MIME format.' . static::$LE  . static::$LE;
         switch ($this->message_type) {
             case 'inline':
                 $body .= $mimepre;
@@ -2546,7 +2627,8 @@ class PHPMailer
                 $body .= $mimepre;
                 $body .= $this->textLine('--' . $this->boundary[1]);
                 $body .= $this->headerLine('Content-Type', static::CONTENT_TYPE_MULTIPART_RELATED . ';');
-                $body .= $this->textLine("\tboundary=\"" . $this->boundary[2] . '"');
+                $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);
@@ -2557,14 +2639,36 @@ class PHPMailer
                 break;
             case 'alt':
                 $body .= $mimepre;
-                $body .= $this->getBoundary($this->boundary[1], $altBodyCharSet, static::CONTENT_TYPE_PLAINTEXT, $altBodyEncoding);
+                $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->getBoundary(
+                    $this->boundary[1],
+                    $bodyCharSet,
+                    static::CONTENT_TYPE_TEXT_HTML,
+                    $bodyEncoding
+                );
                 $body .= $this->encodeString($this->Body, $bodyEncoding);
                 $body .= static::$LE;
                 if (!empty($this->Ical)) {
-                    $body .= $this->getBoundary($this->boundary[1], '', static::CONTENT_TYPE_TEXT_CALENDAR . '; method=REQUEST', '');
+                    $method = static::ICAL_METHOD_REQUEST;
+                    foreach (static::$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;
                 }
@@ -2572,14 +2676,25 @@ class PHPMailer
                 break;
             case 'alt_inline':
                 $body .= $mimepre;
-                $body .= $this->getBoundary($this->boundary[1], $altBodyCharSet, static::CONTENT_TYPE_PLAINTEXT, $altBodyEncoding);
+                $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("\tboundary=\"" . $this->boundary[2] . '"');
+                $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->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]);
@@ -2590,16 +2705,38 @@ class PHPMailer
                 $body .= $mimepre;
                 $body .= $this->textLine('--' . $this->boundary[1]);
                 $body .= $this->headerLine('Content-Type', static::CONTENT_TYPE_MULTIPART_ALTERNATIVE . ';');
-                $body .= $this->textLine("\tboundary=\"" . $this->boundary[2] . '"');
+                $body .= $this->textLine(' boundary="' . $this->boundary[2] . '"');
                 $body .= static::$LE;
-                $body .= $this->getBoundary($this->boundary[2], $altBodyCharSet, static::CONTENT_TYPE_PLAINTEXT, $altBodyEncoding);
+                $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->getBoundary(
+                    $this->boundary[2],
+                    $bodyCharSet,
+                    static::CONTENT_TYPE_TEXT_HTML,
+                    $bodyEncoding
+                );
                 $body .= $this->encodeString($this->Body, $bodyEncoding);
                 $body .= static::$LE;
                 if (!empty($this->Ical)) {
-                    $body .= $this->getBoundary($this->boundary[2], '', static::CONTENT_TYPE_TEXT_CALENDAR . '; method=REQUEST', '');
+                    $method = static::ICAL_METHOD_REQUEST;
+                    foreach (static::$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]);
@@ -2610,16 +2747,27 @@ class PHPMailer
                 $body .= $mimepre;
                 $body .= $this->textLine('--' . $this->boundary[1]);
                 $body .= $this->headerLine('Content-Type', static::CONTENT_TYPE_MULTIPART_ALTERNATIVE . ';');
-                $body .= $this->textLine("\tboundary=\"" . $this->boundary[2] . '"');
+                $body .= $this->textLine(' boundary="' . $this->boundary[2] . '"');
                 $body .= static::$LE;
-                $body .= $this->getBoundary($this->boundary[2], $altBodyCharSet, static::CONTENT_TYPE_PLAINTEXT, $altBodyEncoding);
+                $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("\tboundary=\"" . $this->boundary[3] . '"');
+                $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->getBoundary(
+                    $this->boundary[3],
+                    $bodyCharSet,
+                    static::CONTENT_TYPE_TEXT_HTML,
+                    $bodyEncoding
+                );
                 $body .= $this->encodeString($this->Body, $bodyEncoding);
                 $body .= static::$LE;
                 $body .= $this->attachAll('inline', $this->boundary[3]);
@@ -2646,12 +2794,11 @@ class PHPMailer
                 if (!defined('PKCS7_TEXT')) {
                     throw new Exception($this->lang('extension_missing') . 'openssl');
                 }
-                // @TODO would be nice to use php://temp streams here
-                $file = tempnam(sys_get_temp_dir(), 'mail');
-                if (false === file_put_contents($file, $body)) {
-                    throw new Exception($this->lang('signing') . ' Could not write temp file');
-                }
-                $signed = tempnam(sys_get_temp_dir(), 'signed');
+
+                $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(
@@ -2672,6 +2819,7 @@ class PHPMailer
                         $this->sign_extracerts_file
                     );
                 }
+
                 @unlink($file);
                 if ($sign) {
                     $body = file_get_contents($signed);
@@ -2708,20 +2856,20 @@ class PHPMailer
     protected function getBoundary($boundary, $charSet, $contentType, $encoding)
     {
         $result = '';
-        if ('' == $charSet) {
+        if ('' === $charSet) {
             $charSet = $this->CharSet;
         }
-        if ('' == $contentType) {
+        if ('' === $contentType) {
             $contentType = $this->ContentType;
         }
-        if ('' == $encoding) {
+        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) {
+        if (static::ENCODING_7BIT !== $encoding) {
             $result .= $this->headerLine('Content-Transfer-Encoding', $encoding);
         }
         $result .= static::$LE;
@@ -2758,7 +2906,7 @@ class PHPMailer
             $type[] = 'attach';
         }
         $this->message_type = implode('_', $type);
-        if ('' == $this->message_type) {
+        if ('' === $this->message_type) {
             //The 'plain' message_type refers to the message having a single body element, not that it is plain-text
             $this->message_type = 'plain';
         }
@@ -2806,23 +2954,32 @@ class PHPMailer
      *
      * @return bool
      */
-    public function addAttachment($path, $name = '', $encoding = self::ENCODING_BASE64, $type = '', $disposition = 'attachment')
-    {
+    public function addAttachment(
+        $path,
+        $name = '',
+        $encoding = self::ENCODING_BASE64,
+        $type = '',
+        $disposition = 'attachment'
+    ) {
         try {
-            if (!static::isPermittedPath($path) || !@is_file($path)) {
+            if (!static::isPermittedPath($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) {
+            if ('' === $type) {
                 $type = static::filenameToType($path);
             }
 
-            $filename = basename($path);
-            if ('' == $name) {
+            $filename = (string) static::mb_pathinfo($path, PATHINFO_BASENAME);
+            if ('' === $name) {
                 $name = $filename;
             }
 
+            if (!$this->validateEncoding($encoding)) {
+                throw new Exception($this->lang('encoding') . $encoding);
+            }
+
             $this->attachment[] = [
                 0 => $path,
                 1 => $filename,
@@ -2863,6 +3020,8 @@ class PHPMailer
      * @param string $disposition_type
      * @param string $boundary
      *
+     * @throws Exception
+     *
      * @return string
      */
     protected function attachAll($disposition_type, $boundary)
@@ -2875,7 +3034,7 @@ class PHPMailer
         // Add all attachments
         foreach ($this->attachment as $attachment) {
             // Check if it is a valid disposition_filter
-            if ($attachment[6] == $disposition_type) {
+            if ($attachment[6] === $disposition_type) {
                 // Check for string attachment
                 $string = '';
                 $path = '';
@@ -2887,7 +3046,7 @@ class PHPMailer
                 }
 
                 $inclhash = hash('sha256', serialize($attachment));
-                if (in_array($inclhash, $incl)) {
+                if (in_array($inclhash, $incl, true)) {
                     continue;
                 }
                 $incl[] = $inclhash;
@@ -2896,7 +3055,7 @@ class PHPMailer
                 $type = $attachment[4];
                 $disposition = $attachment[6];
                 $cid = $attachment[7];
-                if ('inline' == $disposition and array_key_exists($cid, $cidUniq)) {
+                if ('inline' === $disposition && array_key_exists($cid, $cidUniq)) {
                     continue;
                 }
                 $cidUniq[$cid] = true;
@@ -2918,42 +3077,41 @@ class PHPMailer
                     );
                 }
                 // RFC1341 part 5 says 7bit is assumed if not specified
-                if (static::ENCODING_7BIT != $encoding) {
+                if (static::ENCODING_7BIT !== $encoding) {
                     $mime[] = sprintf('Content-Transfer-Encoding: %s%s', $encoding, static::$LE);
                 }
 
-                if (!empty($cid)) {
-                    $mime[] = sprintf('Content-ID: <%s>%s', $cid, static::$LE);
+                //Only set Content-IDs on inline attachments
+                if ((string) $cid !== '' && $disposition === 'inline') {
+                    $mime[] = 'Content-ID: <' . $this->encodeHeader($this->secureHeader($cid)) . '>' . static::$LE;
                 }
 
                 // If a filename contains any of these chars, it should be quoted,
                 // but not otherwise: RFC2183 & RFC2045 5.1
                 // Fixes a warning in IETF's msglint MIME checker
                 // Allow for bypassing the Content-Disposition header totally
-                if (!(empty($disposition))) {
+                if (!empty($disposition)) {
                     $encoded_name = $this->encodeHeader($this->secureHeader($name));
-                    if (preg_match('/[ \(\)<>@,;:\\"\/\[\]\?=]/', $encoded_name)) {
+                    if (preg_match('/[ ()<>@,;:"\/\[\]?=]/', $encoded_name)) {
                         $mime[] = sprintf(
                             'Content-Disposition: %s; filename="%s"%s',
                             $disposition,
                             $encoded_name,
                             static::$LE . static::$LE
                         );
+                    } elseif (!empty($encoded_name)) {
+                        $mime[] = sprintf(
+                            'Content-Disposition: %s; filename=%s%s',
+                            $disposition,
+                            $encoded_name,
+                            static::$LE . static::$LE
+                        );
                     } else {
-                        if (!empty($encoded_name)) {
-                            $mime[] = sprintf(
-                                'Content-Disposition: %s; filename=%s%s',
-                                $disposition,
-                                $encoded_name,
-                                static::$LE . static::$LE
-                            );
-                        } else {
-                            $mime[] = sprintf(
-                                'Content-Disposition: %s%s',
-                                $disposition,
-                                static::$LE . static::$LE
-                            );
-                        }
+                        $mime[] = sprintf(
+                            'Content-Disposition: %s%s',
+                            $disposition,
+                            static::$LE . static::$LE
+                        );
                     }
                 } else {
                     $mime[] = static::$LE;
@@ -2984,14 +3142,12 @@ class PHPMailer
      * @param string $path     The full path to the file
      * @param string $encoding The encoding to use; one of 'base64', '7bit', '8bit', 'binary', 'quoted-printable'
      *
-     * @throws Exception
-     *
      * @return string
      */
     protected function encodeFile($path, $encoding = self::ENCODING_BASE64)
     {
         try {
-            if (!static::isPermittedPath($path) || !file_exists($path)) {
+            if (!static::isPermittedPath($path) || !file_exists($path) || !is_readable($path)) {
                 throw new Exception($this->lang('file_open') . $path, self::STOP_CONTINUE);
             }
             $file_buffer = file_get_contents($path);
@@ -3003,7 +3159,10 @@ class PHPMailer
             return $file_buffer;
         } catch (Exception $exc) {
             $this->setError($exc->getMessage());
-
+            $this->edebug($exc->getMessage());
+            if ($this->exceptions) {
+                throw $exc;
+            }
             return '';
         }
     }
@@ -3015,6 +3174,8 @@ class PHPMailer
      * @param string $str      The text to encode
      * @param string $encoding The encoding to use; one of 'base64', '7bit', '8bit', 'binary', 'quoted-printable'
      *
+     * @throws Exception
+     *
      * @return string
      */
     public function encodeString($str, $encoding = self::ENCODING_BASE64)
@@ -3032,7 +3193,7 @@ class PHPMailer
             case static::ENCODING_8BIT:
                 $encoded = static::normalizeBreaks($str);
                 // Make sure it ends with a line break
-                if (substr($encoded, -(strlen(static::$LE))) != static::$LE) {
+                if (substr($encoded, -(strlen(static::$LE))) !== static::$LE) {
                     $encoded .= static::$LE;
                 }
                 break;
@@ -3044,6 +3205,9 @@ class PHPMailer
                 break;
             default:
                 $this->setError($this->lang('encoding') . $encoding);
+                if ($this->exceptions) {
+                    throw new Exception($this->lang('encoding') . $encoding);
+                }
                 break;
         }
 
@@ -3068,7 +3232,7 @@ class PHPMailer
                 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 == $encoded) and !preg_match('/[^A-Za-z0-9!#$%&\'*+\/=?^_`{|}~ -]/', $str)) {
+                    if (($str === $encoded) && !preg_match('/[^A-Za-z0-9!#$%&\'*+\/=?^_`{|}~ -]/', $str)) {
                         return $encoded;
                     }
 
@@ -3086,51 +3250,57 @@ class PHPMailer
                 break;
         }
 
-        //RFCs specify a maximum line length of 78 chars, however mail() will sometimes
-        //corrupt messages with headers longer than 65 chars. See #818
-        $lengthsub = 'mail' == $this->Mailer ? 13 : 0;
-        $maxlen = static::STD_LINE_LENGTH - $lengthsub;
-        // Try to select the encoding which should produce the shortest output
+        if ($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 a third of the content will need encoding, so B encoding will be most efficient
+            // More than 1/3 of the content needs encoding, use B-encode.
             $encoding = 'B';
-            //This calculation is:
-            // max line length
-            // - shorten to avoid mail() corruption
-            // - Q/B encoding char overhead ("` =?<charset>?[QB]?<content>?=`")
-            // - charset name length
-            $maxlen = static::STD_LINE_LENGTH - $lengthsub - 8 - strlen($this->CharSet);
-            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', ' =?' . $this->CharSet . "?$encoding?\\1?=", $encoded);
         } elseif ($matchcount > 0) {
-            //1 or more chars need encoding, use Q-encode
+            // Less than 1/3 of the content needs encoding, use Q-encode.
             $encoding = 'Q';
-            //Recalc max line length for Q encoding - see comments on B encode
-            $maxlen = static::STD_LINE_LENGTH - $lengthsub - 8 - strlen($this->CharSet);
-            $encoded = $this->encodeQ($str, $position);
-            $encoded = $this->wrapText($encoded, $maxlen, true);
-            $encoded = str_replace('=' . static::$LE, "\n", trim($encoded));
-            $encoded = preg_replace('/^(.*)$/m', ' =?' . $this->CharSet . "?$encoding?\\1?=", $encoded);
         } elseif (strlen($str) > $maxlen) {
-            //No chars need encoding, but line is too long, so fold it
-            $encoded = trim($this->wrapText($str, $maxlen, false));
-            if ($str == $encoded) {
-                //Wrapping nicely didn't work, wrap hard instead
-                $encoded = trim(chunk_split($str, static::STD_LINE_LENGTH, static::$LE));
-            }
-            $encoded = str_replace(static::$LE, "\n", trim($encoded));
-            $encoded = preg_replace('/^(.*)$/m', ' \\1', $encoded);
+            // No encoding needed, but value exceeds max line length, use Q-encode to prevent corruption.
+            $encoding = 'Q';
         } else {
-            //No reformatting needed
-            return $str;
+            // 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));
@@ -3194,6 +3364,7 @@ class PHPMailer
         // Base64 has a 4:3 ratio
         $avgLength = floor($length * $ratio * .75);
 
+        $offset = 0;
         for ($i = 0; $i < $mb_length; $i += $offset) {
             $lookBack = 0;
             do {
@@ -3254,7 +3425,6 @@ class PHPMailer
             default:
                 // RFC 2047 section 5.1
                 // Replace every high ascii, control, =, ? and _ characters
-                /** @noinspection SuspiciousAssignmentsInspection */
                 $pattern = '\000-\011\013\014\016-\037\075\077\137\177-\377' . $pattern;
                 break;
         }
@@ -3262,7 +3432,7 @@ class PHPMailer
         if (preg_match_all("/[{$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]);
+            $eqkey = array_search('=', $matches[0], true);
             if (false !== $eqkey) {
                 unset($matches[0][$eqkey]);
                 array_unshift($matches[0], '=');
@@ -3286,6 +3456,10 @@ class PHPMailer
      * @param string $encoding    File encoding (see $Encoding)
      * @param string $type        File extension (MIME) type
      * @param string $disposition Disposition to use
+     *
+     * @throws Exception
+     *
+     * @return bool True on successfully adding an attachment
      */
     public function addStringAttachment(
         $string,
@@ -3294,21 +3468,38 @@ class PHPMailer
         $type = '',
         $disposition = 'attachment'
     ) {
-        // If a MIME type is not specified, try to work it out from the file name
-        if ('' == $type) {
-            $type = static::filenameToType($filename);
-        }
-        // Append to $attachment array
-        $this->attachment[] = [
-            0 => $string,
-            1 => $filename,
-            2 => basename($filename),
-            3 => $encoding,
-            4 => $type,
-            5 => true, // isStringAttachment
-            6 => $disposition,
-            7 => 0,
-        ];
+        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;
     }
 
     /**
@@ -3328,37 +3519,57 @@ class PHPMailer
      * @param string $type        File MIME type
      * @param string $disposition Disposition to use
      *
+     * @throws Exception
+     *
      * @return bool True on successfully adding an attachment
      */
-    public function addEmbeddedImage($path, $cid, $name = '', $encoding = self::ENCODING_BASE64, $type = '', $disposition = 'inline')
-    {
-        if (!static::isPermittedPath($path) || !@is_file($path)) {
-            $this->setError($this->lang('file_access') . $path);
+    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);
+            }
 
-            return false;
-        }
+            // If a MIME type is not specified, try to work it out from the file name
+            if ('' === $type) {
+                $type = static::filenameToType($path);
+            }
 
-        // 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);
+            }
 
-        $filename = basename($path);
-        if ('' == $name) {
-            $name = $filename;
-        }
+            $filename = (string) static::mb_pathinfo($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,
-        ];
+            // 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;
     }
@@ -3378,6 +3589,8 @@ class PHPMailer
      * @param string $type        MIME type - will be used in preference to any automatically derived type
      * @param string $disposition Disposition to use
      *
+     * @throws Exception
+     *
      * @return bool True on successfully adding an attachment
      */
     public function addStringEmbeddedImage(
@@ -3388,27 +3601,63 @@ class PHPMailer
         $type = '',
         $disposition = 'inline'
     ) {
-        // If a MIME type is not specified, try to work it out from the name
-        if ('' == $type and !empty($name)) {
-            $type = static::filenameToType($name);
-        }
-
-        // Append to $attachment array
-        $this->attachment[] = [
-            0 => $string,
-            1 => $name,
-            2 => $name,
-            3 => $encoding,
-            4 => $type,
-            5 => true, // isStringAttachment
-            6 => $disposition,
-            7 => $cid,
-        ];
+        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;
     }
 
     /**
+     * Validate encodings.
+     *
+     * @param string $encoding
+     *
+     * @return bool
+     */
+    protected function validateEncoding($encoding)
+    {
+        return in_array(
+            $encoding,
+            [
+                self::ENCODING_7BIT,
+                self::ENCODING_QUOTED_PRINTABLE,
+                self::ENCODING_BASE64,
+                self::ENCODING_8BIT,
+                self::ENCODING_BINARY,
+            ],
+            true
+        );
+    }
+
+    /**
      * Check if an embedded attachment is present with this cid.
      *
      * @param string $cid
@@ -3418,7 +3667,7 @@ class PHPMailer
     protected function cidExists($cid)
     {
         foreach ($this->attachment as $attachment) {
-            if ('inline' == $attachment[6] and $cid == $attachment[7]) {
+            if ('inline' === $attachment[6] && $cid === $attachment[7]) {
                 return true;
             }
         }
@@ -3434,7 +3683,7 @@ class PHPMailer
     public function inlineImageExists()
     {
         foreach ($this->attachment as $attachment) {
-            if ('inline' == $attachment[6]) {
+            if ('inline' === $attachment[6]) {
                 return true;
             }
         }
@@ -3450,7 +3699,7 @@ class PHPMailer
     public function attachmentExists()
     {
         foreach ($this->attachment as $attachment) {
-            if ('attachment' == $attachment[6]) {
+            if ('attachment' === $attachment[6]) {
                 return true;
             }
         }
@@ -3477,8 +3726,8 @@ class PHPMailer
     {
         $this->RecipientsQueue = array_filter(
             $this->RecipientsQueue,
-            function ($params) use ($kind) {
-                return $params[0] != $kind;
+            static function ($params) use ($kind) {
+                return $params[0] !== $kind;
             }
         );
     }
@@ -3564,7 +3813,7 @@ class PHPMailer
     protected function setError($msg)
     {
         ++$this->error_count;
-        if ('smtp' == $this->Mailer and null !== $this->smtp) {
+        if ('smtp' === $this->Mailer && null !== $this->smtp) {
             $lasterror = $this->smtp->getError();
             if (!empty($lasterror['error'])) {
                 $msg .= $this->lang('smtp_error') . $lasterror['error'];
@@ -3607,9 +3856,9 @@ class PHPMailer
         $result = '';
         if (!empty($this->Hostname)) {
             $result = $this->Hostname;
-        } elseif (isset($_SERVER) and array_key_exists('SERVER_NAME', $_SERVER)) {
+        } elseif (isset($_SERVER) && array_key_exists('SERVER_NAME', $_SERVER)) {
             $result = $_SERVER['SERVER_NAME'];
-        } elseif (function_exists('gethostname') and gethostname() !== false) {
+        } elseif (function_exists('gethostname') && gethostname() !== false) {
             $result = gethostname();
         } elseif (php_uname('n') !== false) {
             $result = php_uname('n');
@@ -3633,22 +3882,23 @@ class PHPMailer
     {
         //Simple syntax limits
         if (empty($host)
-            or !is_string($host)
-            or strlen($host) > 256
+            || !is_string($host)
+            || strlen($host) > 256
+            || !preg_match('/^([a-zA-Z\d.-]*|\[[a-fA-F\d:]+])$/', $host)
         ) {
             return false;
         }
         //Looks like a bracketed IPv6 address
-        if (trim($host, '[]') != $host) {
-            return (bool) filter_var(trim($host, '[]'), FILTER_VALIDATE_IP, FILTER_FLAG_IPV6);
+        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('.', '', $host))) {
             //Is it a valid IPv4 address?
-            return (bool) filter_var($host, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4);
+            return filter_var($host, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4) !== false;
         }
-        if (filter_var('http://' . $host, FILTER_VALIDATE_URL)) {
+        if (filter_var('http://' . $host, FILTER_VALIDATE_URL) !== false) {
             //Is it a syntactically valid hostname?
             return true;
         }
@@ -3666,11 +3916,11 @@ class PHPMailer
     protected function lang($key)
     {
         if (count($this->language) < 1) {
-            $this->setLanguage('en'); // set the default language
+            $this->setLanguage(); // set the default language
         }
 
         if (array_key_exists($key, $this->language)) {
-            if ('smtp_connect_failed' == $key) {
+            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.
@@ -3701,15 +3951,28 @@ class PHPMailer
      *
      * @param string      $name  Custom header name
      * @param string|null $value Header value
+     *
+     * @throws Exception
      */
     public function addCustomHeader($name, $value = null)
     {
-        if (null === $value) {
+        if (null === $value && strpos($name, ':') !== false) {
             // Value passed in as name:value
-            $this->CustomHeader[] = explode(':', $name, 2);
-        } else {
-            $this->CustomHeader[] = [$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;
     }
 
     /**
@@ -3736,36 +3999,45 @@ class PHPMailer
      * @param string        $message  HTML message string
      * @param string        $basedir  Absolute path to a base directory to prepend to relative paths to images
      * @param bool|callable $advanced Whether to use the internal HTML to text converter
-     *                                or your own custom converter @see PHPMailer::html2text()
+     *                                or your own custom converter @return string $message The transformed message Body
+     *
+     * @throws Exception
      *
-     * @return string $message The transformed message Body
+     * @see PHPMailer::html2text()
      */
     public function msgHTML($message, $basedir = '', $advanced = false)
     {
-        preg_match_all('/(src|background)=["\'](.*)["\']/Ui', $message, $images);
+        preg_match_all('/(?<!-)(src|background)=["\'](.*)["\']/Ui', $message, $images);
         if (array_key_exists(2, $images)) {
-            if (strlen($basedir) > 1 && '/' != substr($basedir, -1)) {
+            if (strlen($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 and static::ENCODING_BASE64 == $match[2]) {
+                    if (count($match) === 4 && static::ENCODING_BASE64 === $match[2]) {
                         $data = base64_decode($match[3]);
-                    } elseif ('' == $match[2]) {
+                    } 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
+                    //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 = hash('sha256', $data) . '@phpmailer.0'; // RFC2392 S 2
+                    $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]);
+                        $this->addStringEmbeddedImage(
+                            $data,
+                            $cid,
+                            'embed' . $imgindex,
+                            static::ENCODING_BASE64,
+                            $match[1]
+                        );
                     }
                     $message = str_replace(
                         $images[0][$imgindex],
@@ -3777,22 +4049,23 @@ class PHPMailer
                 if (// Only process relative URLs if a basedir is provided (i.e. no absolute local paths)
                     !empty($basedir)
                     // Ignore URLs containing parent dir traversal (..)
-                    and (strpos($url, '..') === false)
+                    && (strpos($url, '..') === false)
                     // Do not change urls that are already inline images
-                    and 0 !== strpos($url, 'cid:')
+                    && 0 !== strpos($url, 'cid:')
                     // Do not change absolute URLs, including anonymous protocol
-                    and !preg_match('#^[a-z][a-z0-9+.-]*:?//#i', $url)
+                    && !preg_match('#^[a-z][a-z0-9+.-]*:?//#i', $url)
                 ) {
-                    $filename = basename($url);
+                    $filename = static::mb_pathinfo($url, PATHINFO_BASENAME);
                     $directory = dirname($url);
-                    if ('.' == $directory) {
+                    if ('.' === $directory) {
                         $directory = '';
                     }
-                    $cid = hash('sha256', $url) . '@phpmailer.0'; // RFC2392 S 2
-                    if (strlen($basedir) > 1 and '/' != substr($basedir, -1)) {
+                    // RFC2392 S 2
+                    $cid = substr(hash('sha256', $url), 0, 32) . '@phpmailer.0';
+                    if (strlen($basedir) > 1 && '/' !== substr($basedir, -1)) {
                         $basedir .= '/';
                     }
-                    if (strlen($directory) > 1 and '/' != substr($directory, -1)) {
+                    if (strlen($directory) > 1 && '/' !== substr($directory, -1)) {
                         $directory .= '/';
                     }
                     if ($this->addEmbeddedImage(
@@ -3812,7 +4085,7 @@ class PHPMailer
                 }
             }
         }
-        $this->isHTML(true);
+        $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, $advanced));
@@ -3850,7 +4123,7 @@ class PHPMailer
     public function html2text($html, $advanced = false)
     {
         if (is_callable($advanced)) {
-            return call_user_func($advanced, $html);
+            return $advanced($html);
         }
 
         return html_entity_decode(
@@ -4014,7 +4287,7 @@ class PHPMailer
      * Multi-byte-safe pathinfo replacement.
      * Drop-in replacement for pathinfo(), but multibyte- and cross-platform-safe.
      *
-     * @see    http://www.php.net/manual/en/function.pathinfo.php#107461
+     * @see http://www.php.net/manual/en/function.pathinfo.php#107461
      *
      * @param string     $path    A filename or path, does not need to exist as a file
      * @param int|string $options Either a PATHINFO_* constant,
@@ -4026,7 +4299,7 @@ class PHPMailer
     {
         $ret = ['dirname' => '', 'basename' => '', 'extension' => '', 'filename' => ''];
         $pathinfo = [];
-        if (preg_match('#^(.*?)[\\\\/]*(([^/\\\\]*?)(\.([^\.\\\\/]+?)|))[\\\\/\.]*$#im', $path, $pathinfo)) {
+        if (preg_match('#^(.*?)[\\\\/]*(([^/\\\\]*?)(\.([^.\\\\/]+?)|))[\\\\/.]*$#m', $path, $pathinfo)) {
             if (array_key_exists(1, $pathinfo)) {
                 $ret['dirname'] = $pathinfo[1];
             }
@@ -4063,9 +4336,9 @@ class PHPMailer
      * You should avoid this function - it's more verbose, less efficient, more error-prone and
      * harder to debug than setting properties directly.
      * Usage Example:
-     * `$mail->set('SMTPSecure', 'tls');`
+     * `$mail->set('SMTPSecure', static::ENCRYPTION_STARTTLS);`
      *   is the same as:
-     * `$mail->SMTPSecure = 'tls';`.
+     * `$mail->SMTPSecure = static::ENCRYPTION_STARTTLS;`.
      *
      * @param string $name  The property name to set
      * @param mixed  $value The value to set the property to
@@ -4112,7 +4385,7 @@ class PHPMailer
             $breaktype = static::$LE;
         }
         // Normalise to \n
-        $text = str_replace(["\r\n", "\r"], "\n", $text);
+        $text = str_replace([self::CRLF, "\r"], "\n", $text);
         // Now convert LE as needed
         if ("\n" !== $breaktype) {
             $text = str_replace("\n", $breaktype, $text);
@@ -4122,6 +4395,18 @@ class PHPMailer
     }
 
     /**
+     * Remove trailing breaks from a string.
+     *
+     * @param string $text
+     *
+     * @return string The text to remove breaks from
+     */
+    public static function stripTrailingWSP($text)
+    {
+        return rtrim($text, " \r\n\t");
+    }
+
+    /**
      * Return the current line break format string.
      *
      * @return string
@@ -4170,7 +4455,7 @@ class PHPMailer
         $len = strlen($txt);
         for ($i = 0; $i < $len; ++$i) {
             $ord = ord($txt[$i]);
-            if (((0x21 <= $ord) and ($ord <= 0x3A)) or $ord == 0x3C or ((0x3E <= $ord) and ($ord <= 0x7E))) {
+            if (((0x21 <= $ord) && ($ord <= 0x3A)) || $ord === 0x3C || ((0x3E <= $ord) && ($ord <= 0x7E))) {
                 $line .= $txt[$i];
             } else {
                 $line .= '=' . sprintf('%02X', $ord);
@@ -4201,7 +4486,7 @@ class PHPMailer
         $privKeyStr = !empty($this->DKIM_private_string) ?
             $this->DKIM_private_string :
             file_get_contents($this->DKIM_private);
-        if ('' != $this->DKIM_passphrase) {
+        if ('' !== $this->DKIM_passphrase) {
             $privKey = openssl_pkey_get_private($privKeyStr, $this->DKIM_passphrase);
         } else {
             $privKey = openssl_pkey_get_private($privKeyStr);
@@ -4221,7 +4506,7 @@ class PHPMailer
      * Uses the 'relaxed' algorithm from RFC6376 section 3.4.2.
      * Canonicalized headers should *always* use CRLF, regardless of mailer setting.
      *
-     * @see    https://tools.ietf.org/html/rfc6376#section-3.4.2
+     * @see https://tools.ietf.org/html/rfc6376#section-3.4.2
      *
      * @param string $signHeader Header
      *
@@ -4229,13 +4514,15 @@ class PHPMailer
      */
     public function DKIM_HeaderC($signHeader)
     {
-        //Unfold all header continuation lines
-        //Also collapses folded whitespace.
+        //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);
-        $lines = explode("\r\n", $signHeader);
+        //Break headers out into an array
+        $lines = explode(self::CRLF, $signHeader);
         foreach ($lines as $key => $line) {
             //If the header is missing a :, skip it as it's invalid
             //This is likely to happen because the explode() above will also split
@@ -4246,16 +4533,16 @@ class PHPMailer
             list($heading, $value) = explode(':', $line, 2);
             //Lower-case header name
             $heading = strtolower($heading);
-            //Collapse white space within the value
-            $value = preg_replace('/[ \t]{2,}/', ' ', $value);
+            //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
+            //By elimination, the same applies to the field name
             $lines[$key] = trim($heading, " \t") . ':' . trim($value, " \t");
         }
 
-        return implode("\r\n", $lines);
+        return implode(self::CRLF, $lines);
     }
 
     /**
@@ -4263,7 +4550,7 @@ class PHPMailer
      * Uses the 'simple' algorithm from RFC6376 section 3.4.3.
      * Canonicalized bodies should *always* use CRLF, regardless of mailer setting.
      *
-     * @see    https://tools.ietf.org/html/rfc6376#section-3.4.3
+     * @see https://tools.ietf.org/html/rfc6376#section-3.4.3
      *
      * @param string $body Message Body
      *
@@ -4272,13 +4559,13 @@ class PHPMailer
     public function DKIM_BodyC($body)
     {
         if (empty($body)) {
-            return "\r\n";
+            return self::CRLF;
         }
         // Normalize line endings to CRLF
-        $body = static::normalizeBreaks($body, "\r\n");
+        $body = static::normalizeBreaks($body, self::CRLF);
 
         //Reduce multiple trailing line breaks to a single one
-        return rtrim($body, "\r\n") . "\r\n";
+        return static::stripTrailingWSP($body) . self::CRLF;
     }
 
     /**
@@ -4288,109 +4575,143 @@ class PHPMailer
      * @param string $subject      Subject
      * @param string $body         Body
      *
+     * @throws Exception
+     *
      * @return string
      */
     public function DKIM_Add($headers_line, $subject, $body)
     {
         $DKIMsignatureType = 'rsa-sha256'; // Signature & hash algorithms
-        $DKIMcanonicalization = 'relaxed/simple'; // Canonicalization of header/body
+        $DKIMcanonicalization = 'relaxed/simple'; // Canonicalization methods of header & body
         $DKIMquery = 'dns/txt'; // Query method
-        $DKIMtime = time(); // Signature Timestamp = seconds since 00:00:00 - Jan 1, 1970 (UTC time zone)
-        $subject_header = "Subject: $subject";
-        $headers = explode(static::$LE, $headers_line);
-        $from_header = '';
-        $to_header = '';
-        $date_header = '';
-        $current = '';
-        $copiedHeaderFields = '';
-        $foundExtraHeaders = [];
-        $extraHeaderKeys = '';
-        $extraHeaderValues = '';
-        $extraCopyHeaderFields = '';
-        foreach ($headers as $header) {
-            if (strpos($header, 'From:') === 0) {
-                $from_header = $header;
-                $current = 'from_header';
-            } elseif (strpos($header, 'To:') === 0) {
-                $to_header = $header;
-                $current = 'to_header';
-            } elseif (strpos($header, 'Date:') === 0) {
-                $date_header = $header;
-                $current = 'date_header';
-            } elseif (!empty($this->DKIM_extraHeaders)) {
-                foreach ($this->DKIM_extraHeaders as $extraHeader) {
-                    if (strpos($header, $extraHeader . ':') === 0) {
-                        $headerValue = $header;
-                        foreach ($this->CustomHeader as $customHeader) {
-                            if ($customHeader[0] === $extraHeader) {
-                                $headerValue = trim($customHeader[0]) .
-                                               ': ' .
-                                               $this->encodeHeader(trim($customHeader[1]));
-                                break;
-                            }
+        $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']));
                         }
-                        $foundExtraHeaders[$extraHeader] = $headerValue;
-                        $current = '';
-                        break;
+                        //Skip straight to the next header
+                        continue 2;
                     }
                 }
-            } else {
-                if (!empty($$current) and strpos($header, ' =?') === 0) {
-                    $$current .= $header;
-                } else {
-                    $current = '';
-                }
             }
         }
-        foreach ($foundExtraHeaders as $key => $value) {
-            $extraHeaderKeys .= ':' . $key;
-            $extraHeaderValues .= $value . "\r\n";
-            if ($this->DKIM_copyHeaderFields) {
-                $extraCopyHeaderFields .= "\t|" . str_replace('|', '=7C', $this->DKIM_QP($value)) . ";\r\n";
+        $copiedHeaderFields = '';
+        if ($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;
         }
-        if ($this->DKIM_copyHeaderFields) {
-            $from = str_replace('|', '=7C', $this->DKIM_QP($from_header));
-            $to = str_replace('|', '=7C', $this->DKIM_QP($to_header));
-            $date = str_replace('|', '=7C', $this->DKIM_QP($date_header));
-            $subject = str_replace('|', '=7C', $this->DKIM_QP($subject_header));
-            $copiedHeaderFields = "\tz=$from\r\n" .
-                                  "\t|$to\r\n" .
-                                  "\t|$date\r\n" .
-                                  "\t|$subject;\r\n" .
-                                  $extraCopyHeaderFields;
-        }
+        $headerKeys = ' h=' . implode(':', $headersToSignKeys) . ';' . static::$LE;
+        $headerValues = implode(static::$LE, $headersToSign);
         $body = $this->DKIM_BodyC($body);
-        $DKIMlen = strlen($body); // Length of body
         $DKIMb64 = base64_encode(pack('H*', hash('sha256', $body))); // Base64 of packed binary SHA-256 hash of body
-        if ('' == $this->DKIM_identity) {
-            $ident = '';
-        } else {
-            $ident = ' i=' . $this->DKIM_identity . ';';
-        }
-        $dkimhdrs = 'DKIM-Signature: v=1; a=' .
-            $DKIMsignatureType . '; q=' .
-            $DKIMquery . '; l=' .
-            $DKIMlen . '; s=' .
-            $this->DKIM_selector .
-            ";\r\n" .
-            "\tt=" . $DKIMtime . '; c=' . $DKIMcanonicalization . ";\r\n" .
-            "\th=From:To:Date:Subject" . $extraHeaderKeys . ";\r\n" .
-            "\td=" . $this->DKIM_domain . ';' . $ident . "\r\n" .
+        $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 .
-            "\tbh=" . $DKIMb64 . ";\r\n" .
-            "\tb=";
-        $toSign = $this->DKIM_HeaderC(
-            $from_header . "\r\n" .
-            $to_header . "\r\n" .
-            $date_header . "\r\n" .
-            $subject_header . "\r\n" .
-            $extraHeaderValues .
-            $dkimhdrs
+            ' bh=' . $DKIMb64 . ';' . static::$LE .
+            ' b=';
+        //Canonicalize the set of headers
+        $canonicalizedHeaders = $this->DKIM_HeaderC(
+            $headerValues . static::$LE . $dkimSignatureHeader
         );
-        $signed = $this->DKIM_Sign($toSign);
+        $signature = $this->DKIM_Sign($canonicalizedHeaders);
+        $signature = trim(chunk_split($signature, self::STD_LINE_LENGTH - 3, static::$LE . self::FWS));
 
-        return static::normalizeBreaks($dkimhdrs . $signed) . static::$LE;
+        return static::normalizeBreaks($dkimSignatureHeader . $signature);
     }
 
     /**
@@ -4475,7 +4796,7 @@ class PHPMailer
      */
     protected function doCallback($isSent, $to, $cc, $bcc, $subject, $body, $from, $extra)
     {
-        if (!empty($this->action_function) and is_callable($this->action_function)) {
+        if (!empty($this->action_function) && is_callable($this->action_function)) {
             call_user_func($this->action_function, $isSent, $to, $cc, $bcc, $subject, $body, $from, $extra);
         }
     }
@@ -4492,8 +4813,6 @@ class PHPMailer
 
     /**
      * Set an OAuth instance.
-     *
-     * @param OAuth $oauth
      */
     public function setOAuth(OAuth $oauth)
     {
diff --git a/vendor/PHPMailer/PHPMailer/POP3.php b/vendor/PHPMailer/PHPMailer/POP3.php
index 9dab992..cd6fc2f 100644
--- a/vendor/PHPMailer/PHPMailer/POP3.php
+++ b/vendor/PHPMailer/PHPMailer/POP3.php
@@ -3,13 +3,13 @@
  * PHPMailer POP-Before-SMTP Authentication Class.
  * PHP Version 5.5.
  *
- * @see       https://github.com/PHPMailer/PHPMailer/ The PHPMailer GitHub project
+ * @see https://github.com/PHPMailer/PHPMailer/ The PHPMailer GitHub project
  *
  * @author    Marcus Bointon (Synchro/coolbru) <[email protected]>
  * @author    Jim Jagielski (jimjag) <[email protected]>
  * @author    Andy Prevost (codeworxtech) <[email protected]>
  * @author    Brent R. Matzelle (original founder)
- * @copyright 2012 - 2017 Marcus Bointon
+ * @copyright 2012 - 2019 Marcus Bointon
  * @copyright 2010 - 2012 Jim Jagielski
  * @copyright 2004 - 2009 Andy Prevost
  * @license   http://www.gnu.org/copyleft/lesser.html GNU Lesser General Public License
@@ -29,14 +29,14 @@ namespace PHPMailer\PHPMailer;
  *   and then loop through your mail sending script. Providing this process doesn't
  *   take longer than the verification period lasts on your POP3 server, you should be fine.
  * 3) This is really ancient technology; you should only need to use it to talk to very old systems.
- * 4) This POP3 class is deliberately lightweight and incomplete, and implements just
+ * 4) This POP3 class is deliberately lightweight and incomplete, implementing just
  *   enough to do authentication.
  *   If you want a more complete class there are other POP3 classes for PHP available.
  *
- * @author  Richard Davey (original author) <[email protected]>
- * @author  Marcus Bointon (Synchro/coolbru) <[email protected]>
- * @author  Jim Jagielski (jimjag) <[email protected]>
- * @author  Andy Prevost (codeworxtech) <[email protected]>
+ * @author Richard Davey (original author) <[email protected]>
+ * @author Marcus Bointon (Synchro/coolbru) <[email protected]>
+ * @author Jim Jagielski (jimjag) <[email protected]>
+ * @author Andy Prevost (codeworxtech) <[email protected]>
  */
 class POP3
 {
@@ -45,7 +45,7 @@ class POP3
      *
      * @var string
      */
-    const VERSION = '6.0.6';
+    const VERSION = '6.1.5';
 
     /**
      * Default POP3 port number.
@@ -230,6 +230,8 @@ class POP3
         }
 
         //  connect to the POP3 server
+        $errno = 0;
+        $errstr = '';
         $this->pop_conn = fsockopen(
             $host, //  POP3 Host
             $port, //  Port #
@@ -364,7 +366,7 @@ class POP3
      */
     protected function checkResponse($string)
     {
-        if (substr($string, 0, 3) !== '+OK') {
+        if (strpos($string, '+OK') !== 0) {
             $this->setError("Server reported an error: $string");
 
             return false;
diff --git a/vendor/PHPMailer/PHPMailer/SMTP.php b/vendor/PHPMailer/PHPMailer/SMTP.php
index 9651e52..bc08b27 100644
--- a/vendor/PHPMailer/PHPMailer/SMTP.php
+++ b/vendor/PHPMailer/PHPMailer/SMTP.php
@@ -9,7 +9,7 @@
  * @author    Jim Jagielski (jimjag) <[email protected]>
  * @author    Andy Prevost (codeworxtech) <[email protected]>
  * @author    Brent R. Matzelle (original founder)
- * @copyright 2012 - 2017 Marcus Bointon
+ * @copyright 2012 - 2019 Marcus Bointon
  * @copyright 2010 - 2012 Jim Jagielski
  * @copyright 2004 - 2009 Andy Prevost
  * @license   http://www.gnu.org/copyleft/lesser.html GNU Lesser General Public License
@@ -24,8 +24,8 @@ namespace PHPMailer\PHPMailer;
  * PHPMailer RFC821 SMTP email transport class.
  * Implements RFC 821 SMTP commands and provides some utility methods for sending mail to an SMTP server.
  *
- * @author  Chris Ryan
- * @author  Marcus Bointon <[email protected]>
+ * @author Chris Ryan
+ * @author Marcus Bointon <[email protected]>
  */
 class SMTP
 {
@@ -34,7 +34,7 @@ class SMTP
      *
      * @var string
      */
-    const VERSION = '6.0.6';
+    const VERSION = '6.1.5';
 
     /**
      * SMTP line break constant.
@@ -51,34 +51,57 @@ class SMTP
     const DEFAULT_PORT = 25;
 
     /**
-     * The maximum line length allowed by RFC 2822 section 2.1.1.
+     * The maximum line length allowed by RFC 5321 section 4.5.3.1.6,
+     * *excluding* a trailing CRLF break.
+     *
+     * @see https://tools.ietf.org/html/rfc5321#section-4.5.3.1.6
      *
      * @var int
      */
     const MAX_LINE_LENGTH = 998;
 
     /**
+     * The maximum line length allowed for replies in RFC 5321 section 4.5.3.1.5,
+     * *including* a trailing CRLF line break.
+     *
+     * @see https://tools.ietf.org/html/rfc5321#section-4.5.3.1.5
+     *
+     * @var int
+     */
+    const MAX_REPLY_LENGTH = 512;
+
+    /**
      * Debug level for no output.
+     *
+     * @var int
      */
     const DEBUG_OFF = 0;
 
     /**
      * Debug level to show client -> server messages.
+     *
+     * @var int
      */
     const DEBUG_CLIENT = 1;
 
     /**
      * Debug level to show client -> server and server -> client messages.
+     *
+     * @var int
      */
     const DEBUG_SERVER = 2;
 
     /**
      * Debug level to show connection status, client -> server and server -> client messages.
+     *
+     * @var int
      */
     const DEBUG_CONNECTION = 3;
 
     /**
      * Debug level to show all messages.
+     *
+     * @var int
      */
     const DEBUG_LOWLEVEL = 4;
 
@@ -197,7 +220,7 @@ class SMTP
      *
      * @var string|null
      */
-    protected $helo_rply = null;
+    protected $helo_rply;
 
     /**
      * The set of SMTP extensions sent in reply to EHLO command.
@@ -209,7 +232,7 @@ class SMTP
      *
      * @var array|null
      */
-    protected $server_caps = null;
+    protected $server_caps;
 
     /**
      * The most recent reply received from the server.
@@ -239,7 +262,7 @@ class SMTP
             return;
         }
         //Avoid clash with built-in function names
-        if (!in_array($this->Debugoutput, ['error_log', 'html', 'echo']) and is_callable($this->Debugoutput)) {
+        if (is_callable($this->Debugoutput) && !in_array($this->Debugoutput, ['error_log', 'html', 'echo'])) {
             call_user_func($this->Debugoutput, $str, $level);
 
             return;
@@ -260,12 +283,12 @@ class SMTP
             case 'echo':
             default:
                 //Normalize line breaks
-                $str = preg_replace('/\r\n|\r/ms', "\n", $str);
+                $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
+                    //Indent for readability, except for trailing break
                     str_replace(
                         "\n",
                         "\n                   \t                  ",
@@ -348,7 +371,7 @@ class SMTP
                 'Failed to connect to server',
                 '',
                 (string) $errno,
-                (string) $errstr
+                $errstr
             );
             $this->edebug(
                 'SMTP ERROR: ' . $this->error['error']
@@ -361,10 +384,10 @@ class SMTP
         $this->edebug('Connection: opened', self::DEBUG_CONNECTION);
         // SMTP server can take longer to respond, give longer timeout for first read
         // Windows does not have support for this timeout function
-        if (substr(PHP_OS, 0, 3) != 'WIN') {
-            $max = ini_get('max_execution_time');
+        if (strpos(PHP_OS, 'WIN') !== 0) {
+            $max = (int) ini_get('max_execution_time');
             // Don't bother if unlimited
-            if (0 != $max and $timeout > $max) {
+            if (0 !== $max && $timeout > $max) {
                 @set_time_limit($timeout);
             }
             stream_set_timeout($this->smtp_conn, $timeout, 0);
@@ -444,14 +467,14 @@ class SMTP
                 return false;
             }
 
-            $this->edebug('Auth method requested: ' . ($authtype ? $authtype : 'UNSPECIFIED'), self::DEBUG_LOWLEVEL);
+            $this->edebug('Auth method requested: ' . ($authtype ?: 'UNSPECIFIED'), self::DEBUG_LOWLEVEL);
             $this->edebug(
                 'Auth methods available on the server: ' . implode(',', $this->server_caps['AUTH']),
                 self::DEBUG_LOWLEVEL
             );
 
             //If we have requested a specific auth type, check the server supports it before trying others
-            if (null !== $authtype and !in_array($authtype, $this->server_caps['AUTH'])) {
+            if (null !== $authtype && !in_array($authtype, $this->server_caps['AUTH'], true)) {
                 $this->edebug('Requested auth method not available: ' . $authtype, self::DEBUG_LOWLEVEL);
                 $authtype = null;
             }
@@ -460,7 +483,7 @@ class SMTP
                 //If no auth mechanism is specified, attempt to use these, in this order
                 //Try CRAM-MD5 first as it's more secure than the others
                 foreach (['CRAM-MD5', 'LOGIN', 'PLAIN', 'XOAUTH2'] as $method) {
-                    if (in_array($method, $this->server_caps['AUTH'])) {
+                    if (in_array($method, $this->server_caps['AUTH'], true)) {
                         $authtype = $method;
                         break;
                     }
@@ -470,10 +493,10 @@ class SMTP
 
                     return false;
                 }
-                self::edebug('Auth method selected: ' . $authtype, self::DEBUG_LOWLEVEL);
+                $this->edebug('Auth method selected: ' . $authtype, self::DEBUG_LOWLEVEL);
             }
 
-            if (!in_array($authtype, $this->server_caps['AUTH'])) {
+            if (!in_array($authtype, $this->server_caps['AUTH'], true)) {
                 $this->setError("The requested authentication method \"$authtype\" is not supported by the server");
 
                 return false;
@@ -663,13 +686,13 @@ class SMTP
 
         $field = substr($lines[0], 0, strpos($lines[0], ':'));
         $in_headers = false;
-        if (!empty($field) and strpos($field, ' ') === false) {
+        if (!empty($field) && strpos($field, ' ') === false) {
             $in_headers = true;
         }
 
         foreach ($lines as $line) {
             $lines_out = [];
-            if ($in_headers and $line == '') {
+            if ($in_headers && $line === '') {
                 $in_headers = false;
             }
             //Break this line up into several smaller lines if it's too long
@@ -700,7 +723,7 @@ class SMTP
             //Send the lines to the server
             foreach ($lines_out as $line_out) {
                 //RFC2821 section 4.5.2
-                if (!empty($line_out) and $line_out[0] == '.') {
+                if (!empty($line_out) && $line_out[0] === '.') {
                     $line_out = '.' . $line_out;
                 }
                 $this->client_send($line_out . static::LE, 'DATA');
@@ -710,7 +733,7 @@ class SMTP
         //Message data has been sent, complete the command
         //Increase timelimit for end of DATA command
         $savetimelimit = $this->Timelimit;
-        $this->Timelimit = $this->Timelimit * 2;
+        $this->Timelimit *= 2;
         $result = $this->sendCommand('DATA END', '.', 250);
         $this->recordLastTransactionID();
         //Restore timelimit
@@ -745,7 +768,7 @@ class SMTP
      *
      * @return bool
      *
-     * @see    hello()
+     * @see hello()
      */
     protected function sendHello($hello, $host)
     {
@@ -838,7 +861,7 @@ class SMTP
     {
         $noerror = $this->sendCommand('QUIT', 'QUIT', 221);
         $err = $this->error; //Save any error
-        if ($noerror or $close_on_error) {
+        if ($noerror || $close_on_error) {
             $this->close();
             $this->error = $err; //Restore any error from the quit command
         }
@@ -853,14 +876,35 @@ class SMTP
      * Implements from RFC 821: RCPT <SP> TO:<forward-path> <CRLF>.
      *
      * @param string $address The address the message is being sent to
+     * @param string $dsn     Comma separated list of DSN notifications. NEVER, SUCCESS, FAILURE
+     *                        or DELAY. If you specify NEVER all other notifications are ignored.
      *
      * @return bool
      */
-    public function recipient($address)
+    public function recipient($address, $dsn = '')
     {
+        if (empty($dsn)) {
+            $rcpt = 'RCPT TO:<' . $address . '>';
+        } else {
+            $dsn = strtoupper($dsn);
+            $notify = [];
+
+            if (strpos($dsn, 'NEVER') !== false) {
+                $notify[] = 'NEVER';
+            } else {
+                foreach (['SUCCESS', 'FAILURE', 'DELAY'] as $value) {
+                    if (strpos($dsn, $value) !== false) {
+                        $notify[] = $value;
+                    }
+                }
+            }
+
+            $rcpt = 'RCPT TO:<' . $address . '> NOTIFY=' . implode(',', $notify);
+        }
+
         return $this->sendCommand(
             'RCPT TO',
-            'RCPT TO:<' . $address . '>',
+            $rcpt,
             [250, 251]
         );
     }
@@ -894,7 +938,7 @@ class SMTP
             return false;
         }
         //Reject line breaks in all commands
-        if (strpos($commandstring, "\n") !== false or strpos($commandstring, "\r") !== false) {
+        if ((strpos($commandstring, "\n") !== false) || (strpos($commandstring, "\r") !== false)) {
             $this->setError("Command '$command' contained line breaks");
 
             return false;
@@ -904,8 +948,8 @@ class SMTP
         $this->last_reply = $this->get_lines();
         // Fetch SMTP code and possible error code explanation
         $matches = [];
-        if (preg_match('/^([0-9]{3})[ -](?:([0-9]\\.[0-9]\\.[0-9]) )?/', $this->last_reply, $matches)) {
-            $code = $matches[1];
+        if (preg_match('/^([\d]{3})[ -](?:([\d]\\.[\d]\\.[\d]{1,2}) )?/', $this->last_reply, $matches)) {
+            $code = (int) $matches[1];
             $code_ex = (count($matches) > 2 ? $matches[2] : null);
             // Cut off error code from each response line
             $detail = preg_replace(
@@ -916,14 +960,14 @@ class SMTP
             );
         } else {
             // Fall back to simple parsing if regex fails
-            $code = substr($this->last_reply, 0, 3);
+            $code = (int) substr($this->last_reply, 0, 3);
             $code_ex = null;
             $detail = substr($this->last_reply, 4);
         }
 
         $this->edebug('SERVER -> CLIENT: ' . $this->last_reply, self::DEBUG_SERVER);
 
-        if (!in_array($code, (array) $expect)) {
+        if (!in_array($code, (array) $expect, true)) {
             $this->setError(
                 "$command command failed",
                 $detail,
@@ -1014,9 +1058,9 @@ class SMTP
     {
         //If SMTP transcripts are left enabled, or debug output is posted online
         //it can leak credentials, so hide credentials in all but lowest level
-        if (self::DEBUG_LOWLEVEL > $this->do_debug and
+        if (self::DEBUG_LOWLEVEL > $this->do_debug &&
             in_array($command, ['User & Password', 'Username', 'Password'], true)) {
-            $this->edebug('CLIENT -> SERVER: <credentials hidden>', self::DEBUG_CLIENT);
+            $this->edebug('CLIENT -> SERVER: [credentials hidden]', self::DEBUG_CLIENT);
         } else {
             $this->edebug('CLIENT -> SERVER: ' . $data, self::DEBUG_CLIENT);
         }
@@ -1062,7 +1106,7 @@ class SMTP
      *
      * @param string $name Name of SMTP extension or 'HELO'|'EHLO'
      *
-     * @return mixed
+     * @return string|bool|null
      */
     public function getServerExt($name)
     {
@@ -1073,10 +1117,10 @@ class SMTP
         }
 
         if (!array_key_exists($name, $this->server_caps)) {
-            if ('HELO' == $name) {
+            if ('HELO' === $name) {
                 return $this->server_caps['EHLO'];
             }
-            if ('EHLO' == $name || array_key_exists('EHLO', $this->server_caps)) {
+            if ('EHLO' === $name || array_key_exists('EHLO', $this->server_caps)) {
                 return false;
             }
             $this->setError('HELO handshake was used; No information about server extensions available');
@@ -1120,36 +1164,36 @@ class SMTP
         }
         $selR = [$this->smtp_conn];
         $selW = null;
-        while (is_resource($this->smtp_conn) and !feof($this->smtp_conn)) {
+        while (is_resource($this->smtp_conn) && !feof($this->smtp_conn)) {
             //Must pass vars in here as params are by reference
             if (!stream_select($selR, $selW, $selW, $this->Timelimit)) {
                 $this->edebug(
-                    'SMTP -> get_lines(): timed-out (' . $this->Timeout . ' sec)',
+                    'SMTP -> get_lines(): select timed-out in (' . $this->Timelimit . ' sec)',
                     self::DEBUG_LOWLEVEL
                 );
                 break;
             }
             //Deliberate noise suppression - errors are handled afterwards
-            $str = @fgets($this->smtp_conn, 515);
+            $str = @fgets($this->smtp_conn, self::MAX_REPLY_LENGTH);
             $this->edebug('SMTP INBOUND: "' . trim($str) . '"', self::DEBUG_LOWLEVEL);
             $data .= $str;
             // If response is only 3 chars (not valid, but RFC5321 S4.2 says it must be handled),
-            // or 4th character is a space, we are done reading, break the loop,
-            // string array access is a micro-optimisation over strlen
-            if (!isset($str[3]) or (isset($str[3]) and $str[3] == ' ')) {
+            // or 4th character is a space or a line break char, we are done reading, break the loop.
+            // String array access is a significant micro-optimisation over strlen
+            if (!isset($str[3]) || $str[3] === ' ' || $str[3] === "\r" || $str[3] === "\n") {
                 break;
             }
             // Timed-out? Log and break
             $info = stream_get_meta_data($this->smtp_conn);
             if ($info['timed_out']) {
                 $this->edebug(
-                    'SMTP -> get_lines(): timed-out (' . $this->Timeout . ' sec)',
+                    'SMTP -> get_lines(): stream timed-out (' . $this->Timeout . ' sec)',
                     self::DEBUG_LOWLEVEL
                 );
                 break;
             }
             // Now check if reads took too long
-            if ($endtime and time() > $endtime) {
+            if ($endtime && time() > $endtime) {
                 $this->edebug(
                     'SMTP -> get_lines(): timelimit reached (' .
                     $this->Timelimit . ' sec)',
@@ -1289,7 +1333,7 @@ class SMTP
      * If no reply has been received yet, it will return null.
      * If no pattern was matched, it will return false.
      *
-     * @return bool|null|string
+     * @return bool|string|null
      */
     protected function recordLastTransactionID()
     {
@@ -1300,6 +1344,7 @@ class SMTP
         } else {
             $this->last_smtp_transaction_id = false;
             foreach ($this->smtp_transaction_id_patterns as $smtp_transaction_id_pattern) {
+                $matches = [];
                 if (preg_match($smtp_transaction_id_pattern, $reply, $matches)) {
                     $this->last_smtp_transaction_id = trim($matches[1]);
                     break;
@@ -1315,7 +1360,7 @@ class SMTP
      * If no reply has been received yet, it will return null.
      * If no pattern was matched, it will return false.
      *
-     * @return bool|null|string
+     * @return bool|string|null
      *
      * @see recordLastTransactionID()
      */
diff --git a/vendor/PHPMailer/README.md b/vendor/PHPMailer/README.md
index 85f758d..c287e30 100644
--- a/vendor/PHPMailer/README.md
+++ b/vendor/PHPMailer/README.md
@@ -6,7 +6,7 @@ Build status: [![Build Status](https://travis-ci.org/PHPMailer/PHPMailer.svg)](h
 [![Scrutinizer Quality Score](https://scrutinizer-ci.com/g/PHPMailer/PHPMailer/badges/quality-score.png?s=3758e21d279becdf847a557a56a3ed16dfec9d5d)](https://scrutinizer-ci.com/g/PHPMailer/PHPMailer/)
 [![Code Coverage](https://scrutinizer-ci.com/g/PHPMailer/PHPMailer/badges/coverage.png?s=3fe6ca5fe8cd2cdf96285756e42932f7ca256962)](https://scrutinizer-ci.com/g/PHPMailer/PHPMailer/)
 
-[![Latest Stable Version](https://poser.pugx.org/phpmailer/phpmailer/v/stable.svg)](https://packagist.org/packages/phpmailer/phpmailer) [![Total Downloads](https://poser.pugx.org/phpmailer/phpmailer/downloads)](https://packagist.org/packages/phpmailer/phpmailer) [![Latest Unstable Version](https://poser.pugx.org/phpmailer/phpmailer/v/unstable.svg)](https://packagist.org/packages/phpmailer/phpmailer) [![License](https://poser.pugx.org/phpmailer/phpmailer/license.svg)](https://packagist.org/packages/phpmailer/phpmailer)
+[![Latest Stable Version](https://poser.pugx.org/phpmailer/phpmailer/v/stable.svg)](https://packagist.org/packages/phpmailer/phpmailer) [![Total Downloads](https://poser.pugx.org/phpmailer/phpmailer/downloads)](https://packagist.org/packages/phpmailer/phpmailer) [![Latest Unstable Version](https://poser.pugx.org/phpmailer/phpmailer/v/unstable.svg)](https://packagist.org/packages/phpmailer/phpmailer) [![License](https://poser.pugx.org/phpmailer/phpmailer/license.svg)](https://packagist.org/packages/phpmailer/phpmailer) [![API Docs](https://github.com/phpmailer/phpmailer/workflows/Docs/badge.svg)](http://phpmailer.github.io/PHPMailer/)
 
 ## Class Features
 - Probably the world's most popular code for sending email from PHP!
@@ -16,7 +16,7 @@ Build status: [![Build Status](https://travis-ci.org/PHPMailer/PHPMailer.svg)](h
 - Multipart/alternative emails for mail clients that do not read HTML email
 - Add attachments, including inline
 - Support for UTF-8 content and 8bit, base64, binary, and quoted-printable encodings
-- SMTP authentication with LOGIN, PLAIN, CRAM-MD5 and XOAUTH2 mechanisms over SSL and SMTP+STARTTLS transports
+- SMTP authentication with LOGIN, PLAIN, CRAM-MD5, and XOAUTH2 mechanisms over SSL and SMTP+STARTTLS transports
 - Validates email addresses automatically
 - Protect against header injection attacks
 - Error messages in over 50 languages!
@@ -26,21 +26,21 @@ Build status: [![Build Status](https://travis-ci.org/PHPMailer/PHPMailer.svg)](h
 - Much more!
 
 ## Why you might need it
-Many PHP developers utilize email in their code. The only PHP function that supports this is the `mail()` function. However, it does not provide any assistance for making use of popular features such as HTML-based emails and attachments.
+Many PHP developers need to send email from their code. The only PHP function that supports this is [`mail()`](https://www.php.net/manual/en/function.mail.php). However, it does not provide any assistance for making use of popular features such as encryption, authentication, HTML messages, and attachments.
 
-Formatting email correctly is surprisingly difficult. There are myriad overlapping RFCs, requiring tight adherence to horribly complicated formatting and encoding rules - the vast majority of code that you'll find online that uses the `mail()` function directly is just plain wrong!
-*Please* don't be tempted to do it yourself - if you don't use PHPMailer, there are many other excellent libraries that you should look at before rolling your own - try [SwiftMailer](https://swiftmailer.symfony.com/), [Zend/Mail](https://zendframework.github.io/zend-mail/), [eZcomponents](https://github.com/zetacomponents/Mail) etc.
+Formatting email correctly is surprisingly difficult. There are myriad overlapping RFCs, requiring tight adherence to horribly complicated formatting and encoding rules – the vast majority of code that you'll find online that uses the `mail()` function directly is just plain wrong!
+*Please* don't be tempted to do it yourself – if you don't use PHPMailer, there are many other excellent libraries that you should look at before rolling your own. Try [SwiftMailer](https://swiftmailer.symfony.com/), [Zend/Mail](https://zendframework.github.io/zend-mail/), [ZetaComponents](https://github.com/zetacomponents/Mail) etc.
 
-The PHP `mail()` function usually sends via a local mail server, typically fronted by a `sendmail` binary on Linux, BSD and OS X platforms, however, Windows usually doesn't include a local mail server; PHPMailer's integrated SMTP implementation allows email sending on Windows platforms without a local mail server.
+The PHP `mail()` function usually sends via a local mail server, typically fronted by a `sendmail` binary on Linux, BSD, and macOS platforms, however, Windows usually doesn't include a local mail server; PHPMailer's integrated SMTP implementation allows email sending on Windows platforms without a local mail server.
 
 ## License
-This software is distributed under the [LGPL 2.1](http://www.gnu.org/licenses/lgpl-2.1.html) license. Please read LICENSE for information on the software availability and distribution.
+This software is distributed under the [LGPL 2.1](http://www.gnu.org/licenses/lgpl-2.1.html) license, along with the [GPL Cooperation Commitment](https://gplcc.github.io/gplcc/). Please read LICENSE for information on the software availability and distribution.
 
 ## Installation & loading
 PHPMailer is available on [Packagist](https://packagist.org/packages/phpmailer/phpmailer) (using semantic versioning), and installation via [Composer](https://getcomposer.org) is the recommended way to install PHPMailer. Just add this line to your `composer.json` file:
 
 ```json
-"phpmailer/phpmailer": "~6.0"
+"phpmailer/phpmailer": "~6.1"
 ```
 
 or run
@@ -70,15 +70,13 @@ If you're not using the `SMTP` class explicitly (you're probably not), you don't
 If you don't speak git or just want a tarball, click the 'zip' button on the right of the project page in GitHub, though note that docs and examples are not included in the tarball.
 
 ## Legacy versions
-PHPMailer 5.2 (which is compatible with PHP 5.0 - 7.0) is no longer being supported for feature updates, and will only be receiving security updates from now on. You will find the latest version of 5.2 in the [5.2-stable branch](https://github.com/PHPMailer/PHPMailer/tree/5.2-stable), and future versions of 5.2 will be tagged with 5.2.x version numbers, so existing Composer configs should remain working. If you're using PHP 5.5 or later, we recommend you make the necessary changes to switch to the 6.0 release.
+PHPMailer 5.2 (which is compatible with PHP 5.0 - 7.0) is no longer being supported, even for security updates. You will find the latest version of 5.2 in the [5.2-stable branch](https://github.com/PHPMailer/PHPMailer/tree/5.2-stable). If you're using PHP 5.5 or later (which you should be), switch to the 6.x releases.
 
-The 5.2 branch will not receive security updates after December 31st 2018.
-
-## Upgrading from 5.2
+### Upgrading from 5.2
 The biggest changes are that source files are now in the `src/` folder, and PHPMailer now declares the namespace `PHPMailer\PHPMailer`. This has several important effects – [read the upgrade guide](https://github.com/PHPMailer/PHPMailer/tree/master/UPGRADING.md) for more details.
 
 ### Minimal installation
-While installing the entire package manually or with Composer is simple, convenient and reliable, you may want to include only vital files in your project. At the very least you will need [src/PHPMailer.php](https://github.com/PHPMailer/PHPMailer/tree/master/src/PHPMailer.php). If you're using SMTP, you'll need [src/SMTP.php](https://github.com/PHPMailer/PHPMailer/tree/master/src/SMTP.php), and if you're using POP-before SMTP, you'll need [src/POP3.php](https://github.com/PHPMailer/PHPMailer/tree/master/src/POP3.php). You can skip the [language](https://github.com/PHPMailer/PHPMailer/tree/master/language/) folder if you're not showing errors to users and can make do with English-only errors. If you're using XOAUTH2 you will need [src/OAuth.php](https://github.com/PHPMailer/PHPMailer/tree/master/src/OAuth.php) as well as the Composer dependencies for the services you wish to authenticate with. Really, it's much easier to use Composer!
+While installing the entire package manually or with Composer is simple, convenient, and reliable, you may want to include only vital files in your project. At the very least you will need [src/PHPMailer.php](https://github.com/PHPMailer/PHPMailer/tree/master/src/PHPMailer.php). If you're using SMTP, you'll need [src/SMTP.php](https://github.com/PHPMailer/PHPMailer/tree/master/src/SMTP.php), and if you're using POP-before SMTP, you'll need [src/POP3.php](https://github.com/PHPMailer/PHPMailer/tree/master/src/POP3.php). You can skip the [language](https://github.com/PHPMailer/PHPMailer/tree/master/language/) folder if you're not showing errors to users and can make do with English-only errors. If you're using XOAUTH2 you will need [src/OAuth.php](https://github.com/PHPMailer/PHPMailer/tree/master/src/OAuth.php) as well as the Composer dependencies for the services you wish to authenticate with. Really, it's much easier to use Composer!
 
 ## A Simple Example
 
@@ -87,22 +85,25 @@ While installing the entire package manually or with Composer is simple, conveni
 // Import PHPMailer classes into the global namespace
 // These must be at the top of your script, not inside a function
 use PHPMailer\PHPMailer\PHPMailer;
+use PHPMailer\PHPMailer\SMTP;
 use PHPMailer\PHPMailer\Exception;
 
-//Load Composer's autoloader
+// Load Composer's autoloader
 require 'vendor/autoload.php';
 
-$mail = new PHPMailer(true);                              // Passing `true` enables exceptions
+// Instantiation and passing `true` enables exceptions
+$mail = new PHPMailer(true);
+
 try {
     //Server settings
-    $mail->SMTPDebug = 2;                                 // Enable verbose debug output
-    $mail->isSMTP();                                      // Set mailer to use SMTP
-    $mail->Host = 'smtp1.example.com;smtp2.example.com';  // Specify main and backup SMTP servers
-    $mail->SMTPAuth = true;                               // Enable SMTP authentication
-    $mail->Username = '[email protected]';                 // SMTP username
-    $mail->Password = 'secret';                           // SMTP password
-    $mail->SMTPSecure = 'tls';                            // Enable TLS encryption, `ssl` also accepted
-    $mail->Port = 587;                                    // TCP port to connect to
+    $mail->SMTPDebug = SMTP::DEBUG_SERVER;                      // Enable verbose debug output
+    $mail->isSMTP();                                            // Send using SMTP
+    $mail->Host       = 'smtp1.example.com';                    // Set the SMTP server to send through
+    $mail->SMTPAuth   = true;                                   // Enable SMTP authentication
+    $mail->Username   = '[email protected]';                     // SMTP username
+    $mail->Password   = 'secret';                               // SMTP password
+    $mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;         // Enable TLS encryption; `PHPMailer::ENCRYPTION_SMTPS` encouraged
+    $mail->Port       = 587;                                    // TCP port to connect to, use 465 for `PHPMailer::ENCRYPTION_SMTPS` above
 
     //Recipients
     $mail->setFrom('[email protected]', 'Mailer');
@@ -112,11 +113,11 @@ try {
     $mail->addCC('[email protected]');
     $mail->addBCC('[email protected]');
 
-    //Attachments
+    // Attachments
     $mail->addAttachment('/var/tmp/file.tar.gz');         // Add attachments
     $mail->addAttachment('/tmp/image.jpg', 'new.jpg');    // Optional name
 
-    //Content
+    // Content
     $mail->isHTML(true);                                  // Set email format to HTML
     $mail->Subject = 'Here is the subject';
     $mail->Body    = 'This is the HTML message body <b>in bold!</b>';
@@ -125,16 +126,18 @@ try {
     $mail->send();
     echo 'Message has been sent';
 } catch (Exception $e) {
-    echo 'Message could not be sent. Mailer Error: ', $mail->ErrorInfo;
+    echo "Message could not be sent. Mailer Error: {$mail->ErrorInfo}";
 }
 ```
 
 You'll find plenty more to play with in the [examples](https://github.com/PHPMailer/PHPMailer/tree/master/examples) folder.
 
+If you are re-using the instance (e.g. when sending to a mailing list), you may need to clear the recipient list to avoid sending duplicate messages. See [the mailing list example](https://github.com/PHPMailer/PHPMailer/blob/master/examples/mailing_list.phps) for further guidance.
+
 That's it. You should now be ready to use PHPMailer!
 
 ## Localization
-PHPMailer defaults to English, but in the [language](https://github.com/PHPMailer/PHPMailer/tree/master/language/) folder you'll find numerous (48 at the time of writing!) translations for PHPMailer error messages that you may encounter. Their filenames contain [ISO 639-1](http://en.wikipedia.org/wiki/ISO_639-1) language code for the translations, for example `fr` for French. To specify a language, you need to tell PHPMailer which one to use, like this:
+PHPMailer defaults to English, but in the [language](https://github.com/PHPMailer/PHPMailer/tree/master/language/) folder you'll find many translations for PHPMailer error messages that you may encounter. Their filenames contain [ISO 639-1](http://en.wikipedia.org/wiki/ISO_639-1) language code for the translations, for example `fr` for French. To specify a language, you need to tell PHPMailer which one to use, like this:
 
 ```php
 // To load the French version
@@ -152,7 +155,7 @@ Note that in order to reduce PHPMailer's deployed code footprint, the examples a
 
 Complete generated API documentation is [available online](http://phpmailer.github.io/PHPMailer/).
 
-You can generate complete API-level documentation by running `phpdoc` in the top-level folder, and documentation will appear in the `docs` folder, though you'll need to have [PHPDocumentor](http://www.phpdoc.org) installed. You may find [the unit tests](https://github.com/PHPMailer/PHPMailer/tree/master/test/phpmailerTest.php) a good source of how to do various operations such as encryption.
+You can generate complete API-level documentation by running `phpdoc` in the top-level folder, and documentation will appear in the `docs` folder, though you'll need to have [PHPDocumentor](http://www.phpdoc.org) installed. You may find [the unit tests](https://github.com/PHPMailer/PHPMailer/blob/master/test/PHPMailerTest.php) a good source of how to do various operations such as encryption.
 
 If the documentation doesn't cover what you need, search the [many questions on Stack Overflow](http://stackoverflow.com/questions/tagged/phpmailer), and before you ask a question about "SMTP Error: Could not connect to SMTP host.", [read the troubleshooting guide](https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting).
 
diff --git a/vendor/PHPMailer/VERSION b/vendor/PHPMailer/VERSION
index e873808..f8c5c2c 100644
--- a/vendor/PHPMailer/VERSION
+++ b/vendor/PHPMailer/VERSION
@@ -1 +1 @@
-6.0.6
-\ No newline at end of file
+6.1.5
+\ No newline at end of file
author	fox <[email protected]>	2020-04-29 16:50:47 +0000
committer	Gogs <[email protected]>	2020-04-29 16:50:47 +0000
commit	1f9daa1b78be226505949e32984e3b167c4963a5 (patch)
tree	40e84845476cd300a824a9779df673defdff25af
parent	eebc18f00ef5fbaebd4f9a6e43685f87ba8b537f (diff)
parent	bfc890882441e5990a2cba005228d52ff70098b3 (diff)