code: public function reset($key=null) {
  		if ($key) {
  			$key = ucfirst($key);
  			$this->smtp->clear($key);
  			if (isset($this->recipients[$key]))
  				unset($this->recipients[$key]);
  		} else {
  			$this->recipients = array();
  			$this->initSMTP();
  		}
  	}
docs: reset recipients if key was given, or restart whole smtp plugin
  @param null $key