Currenly, there is other company othercompany.com (part of business) that we routed messages internally to them by creating SMTP connector to use their internal exchage server. Now, they have another Exchange server set up. We try to set up messages are routed to othecopmany.com through the second exchange server if the first exchnage server is down. Is there a way to set up ths? (exchange 2003 SP2) thank you.

For 2003, create 2 SMTP connectors for fail over setting each connector to go to the other companys each Exchange server with different costs. Configuring Connectors for Failover If you want to configure connectors to failover automatically, you can create two separate connectors on different bridgehead servers, each with a different cost. Link state for a connector is determined by its local bridgehead server. If the bridgehead server on the preferred connector with the lowest cost is unavailable, that connector is considered unavailable and routing automatically chooses the second connector. When the bridgehead server hosting the connector with the lower cost becomes available, Exchange servers then begin using it again. If you use two connectors with the same cost, Exchange servers will randomly pick which bridgehead server and connector they use, and if this bridgehead server becomes unavailable, they will fail over to the second connector. However, once the first bridgehead server becomes available, the servers will not failback to this server because the route has the same cost as the server they are already using. Advanced Routing Configuration http://technet.microsoft.com/en-us/library/bb124455(EXCHG.65).aspx James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

I assume you have a smarthost defined for their domain in the SMTP connector that represents the first server? Simply add the the other company's 2nd exchange server to that existing SMTP connector as another smart host. If one smarthost is not availible, Exchange will use the other.