Hi All Setup is windows 2000, exchange 2000 and IIS5 all on the same box. The server has been used to send out lots of emails. (thousands) How do I ensure that it is not "Open Relay". How do I prevent "Open Relay" Mail is only sent by local users all of which use outlook 97 or outlook 2000. I had sent to relay only for authenticated users but perhaps I missed another required setting. Thanks Frustrated Admin