Here is my question:We currently have 2 Ironport Mail Security Appliances, Is it possible to setup our Send connector with the namespace of * to use a smart host and put in both the IP of our primary Ironport appliance and our secondary Ironport appliance? If so how does it handle the 2 IPs? Does it just try and use the first IP listed and then if it can't contact that smart host then it uses the second IP?

Yes you can give 2 IPs to SMTP send connector... When you add tow IPs in smtp send connectors, those are load balanced and provide fault tolerance when anyone goes down.... This will give you idea about other questions... Message Relay to Third-Party SMTP Servers If an SMTP Send connector is configured to use more than one smart host, connection requests are load balanced across the smart hosts. If a smart host is not available, fault tolerance is provided by retrying the connection to another smart host that is configured on the connector. Load Balancing and Fault Tolerance for Transport Servers -http://technet.microsoft.com/en-us/library/bb267003.aspx Amit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com