Zend_Mail::getMimeBoundary PHP Method

    public function getMimeBoundary()
    {
        return $this->_mimeBoundary;
    }

 /**
  * Send a mail using this transport
  * 
  * @param Zend_Mail $mail 
  * @access public
  * @return void
  * @throws Zend_Mail_Transport_Exception if mail is empty
  */
 public function send(Zend_Mail $mail)
 {
     $this->_isMultipart = false;
     $this->_mail = $mail;
     $this->_parts = $mail->getParts();
     $mime = $mail->getMime();
     // Build body content
     $this->_buildBody();
     // Determine number of parts and boundary
     $count = count($this->_parts);
     $boundary = null;
     if ($count < 1) {
         throw new Zend_Mail_Transport_Exception('Empty mail cannot be sent');
     }
     if ($count > 1) {
         // Multipart message; create new MIME object and boundary
         $mime = new Zend_Mime($this->_mail->getMimeBoundary());
         $boundary = $mime->boundary();
     } elseif ($this->_isMultipart) {
         // multipart/alternative -- grab boundary
         $boundary = $this->_parts[0]->boundary;
     }
     // Determine recipients, and prepare headers
     $this->recipients = implode(',', $mail->getRecipients());
     $this->_prepareHeaders($this->_getHeaders($boundary));
     // Create message body
     // This is done so that the same Zend_Mail object can be used in
     // multiple transports
     $message = new Zend_Mime_Message();
     $message->setParts($this->_parts);
     $message->setMime($mime);
     $this->body = $message->generateMessage($this->EOL);
     // Send to transport!
     $this->_sendMail();
 }