private function send_email($template_name, $subject, $to, $recipient_name, $content=array(), $pdf=null)
    {
        //FOR TESTING
        $amachome = 'http://hicalibertest.com.au/amac/'; //home_url();
        $amaclogo = $amachome.'/wp-content/themes/amac/assets/images/logo.png'; //home_url('/wp-content/themes/amac/assets/images/logo.png');

        $message = array(
            'subject' => $subject,
            'to' => array(
                array(
                    'email' => $to,
                    'name' => $recipient_name,
                    'type' => 'to'
                )
            ),
            'html' => array(
                array( 'name'=>'amachome', 'content'=> "<a href='$amachome'>www.amac.org.au</a>" ),
                array( 'name'=>'amaclogo', 'content'=> "<img style='width:100%;' src='$amaclogo'></img>" ),
            )
        );

        foreach ($content as $key => $value) 
        {
            $message['html'][] = array('name'=>$key, 'content'=>$value);
        }

        if(!empty($pdf))
        {
            $message['attachments'] =  DocHandler::pdf_upload_dir($pdf);
        }
        
        wpMandrill::sendEmail($message, null ,$template_name);
    }