I've run into more and more message failures due to relay being detected from the far end server. Ido not perform anyrelayoperations but I think it has to do with what my SMTP server FQDN answers with from ehlo. I have my internet domain separated from my functional domain with firewalls like all good security practices dictate. All my MX/A/Name records are populated and forward/reverse lookups respond with a proper trail on the internet face. Internal domain has a different name and address scheme and it has zero issues to mail or dns on theinternal segments containing Exchange 2003 servers. The firewalls are the only link between these domains. When the Exchange SMTP Virtual server was configured (Propereties>Delivery>Advanced>FQDN) with the internal FQDN of the mail servers it may be the underlying causeof these failures as this domain does not exist on the internet side of the firewall. My question is, what will happen if I change this SMTP FQDN entry to the externalFQDNwithmy internal mail routing since the externalFQDN is not present inside the firewall? MS help on this context box states it can be configured with an external FQDN. Will the internal mail flow attempt to reroute it out the firewall and back in just to deliver a message from one server to another internally? Do I configure all Exchange servers that deliver mail externally to the same external FQDN or do they need to be different? ( mail.domain and mail2.domain) I'm pretty confident this will resolve the external message issue but I can't take a chance in breaking the internal traffic routes. Thanx Coty