diff --git a/class.phpmailer.php b/class.phpmailer.php
index f5ca89709..b467c716f 100644
--- a/class.phpmailer.php
+++ b/class.phpmailer.php
@@ -479,6 +479,13 @@ class PHPMailer
      */
     protected $CustomHeader = array();
 
+    /**
+     * The most recent Message-ID (including angular brackets).
+     * @type string
+     * @access protected
+     */
+    protected $lastMessageID = '';
+
     /**
      * The message's MIME type.
      * @type string
@@ -806,6 +813,18 @@ public function setFrom($address, $name = '', $auto = true)
         return true;
     }
 
+    /**
+     * Return the Message-ID header of the last email.
+     * Technically this is the value from the last time the headers were created,
+     * but it also the message ID of the last sent message except in
+     * pathological cases.
+     * @return string
+     */
+    public function GetLastMessageID()
+    {
+        return $this->lastMessageID;
+    }
+
     /**
      * Check that a string looks like an email address.
      * @param string $address The email address to check
@@ -1606,10 +1625,11 @@ public function createHeader()
         }
 
         if ($this->MessageID != '') {
-            $result .= $this->headerLine('Message-ID', $this->MessageID);
+            $this->lastMessageID = $this->MessageID;
         } else {
-            $result .= sprintf("Message-ID: <%s@%s>%s", $uniq_id, $this->serverHostname(), $this->LE);
+            $this->lastMessageID = sprintf("<%s@%s>", $uniq_id, $this->ServerHostname());
         }
+        $result .= $this->HeaderLine('Message-ID', $this->lastMessageID);
         $result .= $this->headerLine('X-Priority', $this->Priority);
         if ($this->XMailer == '') {
             $result .= $this->headerLine(
@@ -2914,7 +2934,7 @@ public static function _mime_types($ext = '')
             'avi' => 'video/x-msvideo',
             'movie' => 'video/x-sgi-movie'
         );
-        return (!isset($mimes[strtolower($ext)])) ? 'application/octet-stream' : $mimes[strtolower($ext)];
+        return (array_key_exists(strtolower($ext), $mimes) ? $mimes[strtolower($ext)]: 'application/octet-stream');
     }
 
     /**