Just like the title says: if you have multiple smarthosts in an Exchange 2007 Send Connector, what order, if any, are the hosts tried? Random (roundrobin like behavior) or top to bottom?
Setting up one send connector with two defined smarthosts is the proper way of load balancing/ setting up fault tolerance for outbound email distribution.
If you use two equal cost send connectors with different smarthosts, mail will only be routed to one of the two connectors. However, I'm not positive on what order the smart hosts are utilized. I would believe it to be top to bottom, but I can't find a specific on it, or have the ability to test at the moment.