Zend_Mail::getRecipients PHP Method

    public function getRecipients()
    {
        return array_keys($this->_recipients);
    }

 public function sendMail(Zend_Mail $mail, $body, $headers)
 {
     /**
      * @todo error checking
      */
     mail(join(',', $mail->getRecipients()), $mail->getSubject(), $body, $headers);
 }