<A target="_blank" href="http://www.bleedyellow.com/blogs/port1352/entry/sending_smtp_to_secureserver_net_from_dedicated_outbound_smtp_servers?lang=en">David Brown explains the "ReceiveResponse: 554" message you may get when dedicated Domino</A> outbound SMTP servers try to connect to GoDaddy hosted domains. He has also posted the "fix" to get your servers to communicate.