diff --git a/include/class.mailparse.php b/include/class.mailparse.php
index 48a402dfb013e724f1b8eb9c1d683007fa5d896e..42389ebc08432b29f4959a8a644e8d9c1ff39f9e 100644
--- a/include/class.mailparse.php
+++ b/include/class.mailparse.php
@@ -456,22 +456,36 @@ class Mail_Parse {
         return Mail_Parse::parsePriority($this->getHeader());
     }
 
-    function parsePriority($header=null){
-
-        $priority=0;
-        if($header && ($begin=strpos($header,'X-Priority:'))!==false){
-            $begin+=strlen('X-Priority:');
-            $xpriority=preg_replace("/[^0-9]/", "",substr($header, $begin, strpos($header,"\n",$begin) - $begin));
-            if(!is_numeric($xpriority))
-                $priority=0;
-            elseif($xpriority>4)
-                $priority=1;
-            elseif($xpriority>=3)
-                $priority=2;
-            elseif($xpriority>0)
-                $priority=3;
-        }
-        return $priority;
+    static function parsePriority($header=null){
+    	
+    	if (! $header)
+    		return 0;
+    	// Test for normal "X-Priority: INT" style header & stringy version.
+    	// Allows for Importance possibility.
+    	$matching_char = '';
+    	if (preg_match ( '/priority: (\d|\w)/i', $header, $matching_char )
+    			|| preg_match ( '/importance: (\d|\w)/i', $header, $matching_char )) {
+    		switch ($matching_char[1]) {
+    			case 'h' :
+    			case 'H' :// high
+    			case 'u':
+    			case 'U': //Urgent
+    			case 6 :
+    			case 5 :
+    				return 1;
+    			case 'n' : // normal
+    			case 'N' :
+    			case 4 :
+    			case 3 :
+    				return 2;
+    			case 'l' : // low
+    			case 'L' :
+    			case 2 :
+    			case 1 :
+    				return 3;
+    		}
+    	}
+    	return 0;
     }
 
     function parseAddressList($address){
diff --git a/setup/test/run-tests.php b/setup/test/run-tests.php
index ecd7bb3c73a4f092b8684c3a84f04a010e296d16..326f8be18f9ba349b2d908eab241be1f60d817d4 100644
--- a/setup/test/run-tests.php
+++ b/setup/test/run-tests.php
@@ -2,6 +2,9 @@
 <?php
 if (php_sapi_name() != 'cli') exit();
 
+//Allow user to select suite
+$selected_test = (isset($argv[1])) ? $argv[1] : false;
+
 require_once "tests/class.test.php";
 
 if (!function_exists('get_osticket_root_path')) {
@@ -63,6 +66,8 @@ foreach (glob_recursive(dirname(__file__)."/tests/test.*.php") as $t) {
     $class = (include $t);
     if (!is_string($class))
         continue;
+    if($selected_test && ($class != $selected_test))
+    	continue;
     $test = new $class();
     echo "Running: " . $test->name . "\n";
     $test->run();
diff --git a/setup/test/tests/test.header_functions.php b/setup/test/tests/test.header_functions.php
new file mode 100644
index 0000000000000000000000000000000000000000..b64a1c400946e590e01a8742d47d9a09ffefbd46
--- /dev/null
+++ b/setup/test/tests/test.header_functions.php
@@ -0,0 +1,112 @@
+<?php
+require_once "class.test.php";
+define('INCLUDE_DIR', realpath(dirname(__file__).'/../../../include').'/');
+define('PEAR_DIR', INCLUDE_DIR.'/pear/');
+require_once INCLUDE_DIR."class.mailparse.php";
+
+abstract class Priorities {
+	const HIGH_PRIORITY = 1;
+	const NORMAL_PRIORITY = 2;
+	const LOW_PRIORITY = 3;
+	const NO_PRIORITY = 0;
+}
+
+class TestHeaderFunctions extends Test {
+    var $name = "Email Header Function Algorithm Regression Tests.";
+    
+    function testMailParsePriority() {
+    	$func_class_method = array('Mail_Parse','parsePriority');
+    	$strlen_base = strlen($this->h());
+
+    	foreach ( array (
+    			'X-Priority: isNAN' => Priorities::NO_PRIORITY, // input => output
+    			'X-Priority: 1' => Priorities::LOW_PRIORITY,
+    			'X-Priority: 2' => Priorities::LOW_PRIORITY,
+    			'X-Priority: 3' => Priorities::NORMAL_PRIORITY,
+    			'X-Priority: 4' => Priorities::NORMAL_PRIORITY,
+    			'X-Priority: 5' => Priorities::HIGH_PRIORITY,
+    			'X-Priority: 6' => Priorities::HIGH_PRIORITY,
+    			'No priority set' => Priorities::NO_PRIORITY,
+    			'Priority: normal' => Priorities::NORMAL_PRIORITY,
+    			'xyz-priority: high' => Priorities::HIGH_PRIORITY,
+    			'Priority: high' => Priorities::HIGH_PRIORITY,
+    			'priority: low' => Priorities::LOW_PRIORITY,
+    			'x-priority: 1000' => Priorities::LOW_PRIORITY, // only matches first 1, not the full 1000
+    			'priority: 3' => Priorities::NORMAL_PRIORITY,
+    			'IPM-Importance: low' => Priorities::LOW_PRIORITY,
+    			'My-Importance: URGENT' => Priorities::HIGH_PRIORITY,
+    			'Urgency: High' => Priorities::NO_PRIORITY, //urgency doesn't match.. maybe it should?
+    			'X-Importance: 5' => Priorities::HIGH_PRIORITY,
+    			'' => Priorities::NO_PRIORITY
+    	) as $priority => $response ) {
+    		$this->assert(is_int($response), "Setup fail, function should only return Integer values");
+    		//get header
+    		$header = $this->h($priority);
+    		
+    		if(strlen($priority)){
+    			$this->assert((strlen($header) > $strlen_base), "Setup fail, function h not returning correct string length");
+    		}
+    		if (! (call_user_func_array ($func_class_method , array($header) ) == $response)){
+    			//TODO: make line number dynamic
+    			$this->fail ( "class.mailparse.php", 351, "Algorithm mistake: $priority should return $response!" );
+    		}else{
+    			$this->pass();
+    		}
+    	}
+  
+    }
+    
+    /**
+     * Generate some header text to test with. Allows insertion of a known header variable
+     * 
+     * @param string $setPriority
+     * @return string
+     */
+    function h($setPriority = "") {
+    	return <<<HEADER
+Delivered-To: clonemeagain@gmail.com
+Received: by 10.69.18.42 with SMTP id gj10csp88238pbd;
+Fri, 20 Dec 2013 10:08:25 -0800 (PST)
+X-Received: by 10.224.13.80 with SMTP id b16mr16256982qaa.73.1387562904239;
+Fri, 20 Dec 2013 10:08:24 -0800 (PST)
+Return-Path: <noreply@github.com>
+Received: from github-smtp2a-ext-cp1-prd.iad.github.net (github-smtp2-ext5.iad.github.net. [192.30.252.196])
+by mx.google.com with ESMTPS id k3si6568083qao.74.2013.12.20.10.08.23
+for <clonemeagain@gmail.com>
+(version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128);
+Fri, 20 Dec 2013 10:08:23 -0800 (PST)
+Received-SPF: pass (google.com: domain of noreply@github.com designates 192.30.252.196 as permitted sender) client-ip=192.30.252.196;
+Authentication-Results: mx.google.com;
+spf=pass (google.com: domain of noreply@github.com designates 192.30.252.196 as permitted sender) smtp.mail=noreply@github.com
+Date: Fri, 20 Dec 2013 10:08:23 -0800
+From: Jared Hancock <notifications@github.com>
+Reply-To: "osTicket/osTicket-1.8" <reply+i-BUNCHORANDOMGIBBERIBBERISH-BUNCHORANDOMGIBBERIBBERISH@reply.github.com>
+To: "osTicket/osTicket-1.8" <osTicket-1.8@noreply.github.com>
+Cc: clonemeagain <clonemeagain@gmail.com>
+Message-ID: <osTicket/osTicket-1.8/pull/336/issue_event/82864993@github.com>
+In-Reply-To: <osTicket/osTicket-1.8/pull/336@github.com>
+References: <osTicket/osTicket-1.8/pull/336@github.com>
+Subject: Re: [osTicket-1.8] Landing page inline image correction (#336)
+Mime-Version: 1.0
+Content-Type: multipart/alternative;
+boundary="--==_mimepart_52b4879729712_d621217cfc567e3";
+charset=UTF-8
+Content-Transfer-Encoding: 7bit
+Precedence: list
+X-GitHub-Recipient: clonemeagain
+X-GitHub-Reason: author
+List-ID: osTicket/osTicket-1.8 <osTicket-1.8.osTicket.github.com>
+List-Archive: https://github.com/osTicket/osTicket-1.8
+List-Post: <mailto:reply+i-BUNCHORANDOMGIBBERIBBERISH-BUNCHORANDOMGIBBERIBBERISH@reply.github.com>
+List-Unsubscribe: <mailto:unsub+i-BUNCHORANDOMGIBBERIBBERISH-BUNCHORANDOMGIBBERIBBERISH@reply.github.com>,
+<https://github.com/notifications/unsubscribe/BUNCHORANDOMGIBBERIBBERISH-BUNCHORANDOMGIBBERIBBERISH-BUNCHORANDOMGIBBERIBBERISH-BUNCHORANDOMGIBBERIBBERISH-BUNCHORANDOMGIBBERIBBERISH-BUNCHORANDOMGIBBERIBBERISH-BUNCHORANDOMGIBBERIBBERISH-BUNCHORANDOMGIBBERIBBERISH-BUNCHORANDOMGIBBERIBBERISHBUNCHORANDOMGIBBERIBBERISHBUNCHORANDOMGIBBERIBBERISH>
+X-Auto-Response-Suppress: All
+X-GitHub-Recipient-Address: clonemeagain@gmail.com
+$setPriority
+    	
+HEADER;
+    }
+
+}
+return 'TestHeaderFunctions';
+?>