Here is the situation that I have and I am new to the game of Exchange Server 2003. We are running Exchange server in a cluster mode and are looking at blocking any external emails that are spoofing our address (i.e. *@hurryup.com). We have been able to block those emails from coming in, but we have mutiple scanners that we are using for scanning PDF documents via email, using our email accounts (i.e. John.doe@hurryup.com). The Scanners are pointed to the Exchange server and using the SMTP services, port 25.It has beennoticed that when we receive the email in our Inbox in Outlook, Exchange sees it as an external IP/device (by viewing the Internet Headers.) Any other internal email from Outlook, going through Exchange, does not have an Internet Header. When we pull the trigger on the filter to block any external email form coming in with the *@hurryup.com address, Exchange is also blocking the emails from the scanners. So, we are wondering where, in Exchange(whether System Manager or Cluster Administration), would we set up a rule or condition that would allow those internal email scanning devices to be accepted and still block the external emails. Any thoughts or help would be greatly appreciated.