IMP_Contents::getHeaderAndMarkAsSeen PHP Method

    public function getHeaderAndMarkAsSeen($type = self::HEADER_OB)
    {
        $mbox = $this->getMailbox();
        if ($mbox->readonly) {
            $seen = false;
        } else {
            $seen = true;
            if (isset($this->_header)) {
                try {
                    $imp_imap = $mbox->imp_imap;
                    $imp_imap->store($mbox, array('add' => array(Horde_Imap_Client::FLAG_SEEN), 'ids' => $imp_imap->getIdsOb($this->getUid())));
                } catch (Exception $e) {
                }
            }
        }
        return $this->_getHeader($type, $seen);
    }

 /**
  * Loads the MIME headers object internally.
  */
 protected function _loadHeaders()
 {
     return $this->_peek ? $this->contents->getHeader() : $this->contents->getHeaderAndMarkAsSeen();
 }