sendmail 8.9 open relay ?

Hi folks, just received a message from the "famous" :-) ORBS database claiming that our server is open for mail-relaying. Hmm, as far as I remeber, this was correct for the earlier versions and I was told (from SuSE I think, but not sure about this) that sendmail would be safe starting with SuSE6.0. Well, I did install SuSE6.0 and thought this would be ok now. I did some checks by myself and found out that the server is indeed still open for relays. Did I forget some configuration details ? Or what else can I do to close mail-relaying ? Thanks in advance. --- Stephan