Zend_Mail::setBodyHtml PHP Method

    public function setBodyHtml($html, $charset = null, $encoding = Zend_Mime::ENCODING_QUOTEDPRINTABLE)
    {
        if ($charset === null) {
            $charset = $this->_charset;
        }
        $mp = new Zend_Mime_Part($html);
        $mp->encoding = $encoding;
        $mp->type = Zend_Mime::TYPE_HTML;
        $mp->disposition = Zend_Mime::DISPOSITION_INLINE;
        $mp->charset = $charset;
        $this->_bodyHtml = $mp;
        return $this;
    }

 /**
  * Send an email.
  *
  * @param array $params Config object.
  *  Required keys: to, subject, message
  *  Optional keys: replyTo
  * @param array $viewParams Any values you wish to send to the HTML mail template
  * @param array $attachments
  * @return bool
  */
 public function send(array $params, array $viewParams = array(), $attachments = array())
 {
     $this->_validateParams($params);
     $mail = new Zend_Mail($this->getCharacterEncoding());
     $mail->setSubject($params['subject']);
     $mail->setBodyText($this->_getPlainBodyText($params));
     $mail->setFrom($this->getFromAddress(), $this->getFromName());
     $mail->addTo($params['to']);
     $viewParams['subject'] = $params['subject'];
     if ($this->getHtmlTemplate()) {
         $viewParams['message'] = isset($params['message']) ? $params['message'] : '';
         $viewParams['htmlMessage'] = isset($params['htmlMessage']) ? $params['htmlMessage'] : '';
         $mail->setBodyHtml($this->_renderView($viewParams));
     } elseif (isset($params['htmlMessage'])) {
         $mail->setBodyHtml($params['htmlMessage']);
     }
     if (!empty($params['replyTo'])) {
         $mail->setReplyTo($params['replyTo']);
     }
     if (!empty($params['cc'])) {
         $mail->addCc($params['cc']);
     }
     if (!empty($params['bcc'])) {
         $mail->addBcc($params['bcc']);
     }
     $this->addAttachments($attachments);
     $mimeParts = array_map(array($this, '_attachmentToMimePart'), $this->_attachments);
     array_walk($mimeParts, array($mail, 'addAttachment'));
     return $mail->send($this->getTransport());
 }