protected function _syncStatus($mailbox)
    {
        $status = $this->status(
            $mailbox,
            Horde_Imap_Client::STATUS_HIGHESTMODSEQ |
            Horde_Imap_Client::STATUS_MESSAGES |
            Horde_Imap_Client::STATUS_UIDNEXT_FORCE |
            Horde_Imap_Client::STATUS_UIDVALIDITY
        );

        $fields = array('uidnext', 'uidvalidity');
        if (empty($status['highestmodseq'])) {
            $fields[] = 'messages';
        } else {
            $fields[] = 'highestmodseq';
        }

        $out = array();
        $sync_map = array_flip(Horde_Imap_Client_Data_Sync::$map);

        foreach ($fields as $val) {
            $out[$sync_map[$val]] = $status[$val];
        }

        return array_filter($out);
    }