mData.metadataChanged(mMailbox);
	void alterUnread(boolean unread) throws ServiceException {	    // detect NOOPs and bail	    if (unread == isUnread())	        return;	    if (!mMailbox.mUnreadFlag.canTag(this))	        throw MailServiceException.CANNOT_TAG();        if (!canAccess(ACL.RIGHT_WRITE))            throw ServiceException.PERM_DENIED("you do not have the required rights on the item");	    markItemModified(Change.MODIFIED_UNREAD);	    updateUnread(unread ? 1 : -1);	    DbMailItem.alterUnread(this, unread);	}