cd sites/all/libraries
git clone https://github.com/PHPMailer/PHPMailer
ln -s PHPMailer phpmailer

/**
 * Load the PHPMailer library.
 *
 * @return
 *   TRUE if the PHPMailer library is loaded, FALSE otherwise.
 */
function smtp_load_library() {
  // Include the PHPMailer class (which includes the SMTP class).
  if (!class_exists('PHPMailer')) {
	// First try using the libraries module.
	if (module_exists('libraries')) {
	   // $smtp_phpmailer_library = module_invoke('libraries', 'get_path', 'phpmailer') . '/class.phpmailer.php';
	   $smtp_phpmailer_library = module_invoke('libraries', 'get_path', 'phpmailer') . '/PHPMailerAutoload.php';
	 }
	 //If you aren't using libraries, then check a couple other places.
	 else {
	   //Look in the default libraries location
	   // $smtp_phpmailer_library = 'sites/all/libraries/phpmailer/class.phpmailer.php';
	   $smtp_phpmailer_library = 'sites/all/libraries/phpmailer/PHPMailerAutoload.php';
	   //If the default libraries doesn't exist, then try the old module location.
	   if (!file_exists($smtp_phpmailer_library)) {
		 // $smtp_phpmailer_library = drupal_get_path('module', 'smtp') .'/phpmailer/class.phpmailer.php';
		 $smtp_phpmailer_library = drupal_get_path('module', 'smtp') .'/phpmailer/PHPMailerAutoload.php';
	   }
	 }
	 //Now include whatever you found.
	 if (file_exists($smtp_phpmailer_library)) {
		require_once($smtp_phpmailer_library);
	 }
  }
  
  // Tell the caller if PHPMailer class exists.
  return class_exists('PHPMailer');
}