Hello. My name is António and I recently moved to a new job. All the structure was already setup. It contains (just for visualization, heheh :P) a Nokia Firewall, a ISA Server, Active Directory and Exchange Server 2000 (all the servers with Windows 2000). I have tested many times the open relay at the Exchange and all the results were negative (Open Relay is closed). I also read an article about SMTP Authority problem, and altered the internal password policy to solve that problem. Even tough, a have a great problem at the SMTP protocol. I keep receiving thousands of SPAM messages in several domains (such as aol.com, yahoo.com, etc., and note that I freezed the majoity), and every day, new domains get in queue list with retry status carring SPAM messages. I don´t know waht more to do. I have Mcafee SpamKiller installed and he works fine to me... Is it possible to be a internal computer to be doing this? Please help me... I'm stuck in this, and I'm losing all the hope in Microsoft. Thank you all. Best Regards.