Facts: Windows Exchange 2007 in Active Directory & We have a member server (W2K3) using IIS SMTP for service center helpdesk. We also have a member server running as our mail excahnge server (Exchange 2007 on W2K3) (216.x.x.x). When service center "helpdesk" sends / receives email (10.1.0.17), no messages are being sent to both internal and external e-mail accounts. Any ideas how to resolve? Thanks