One thing that makes no sense to me is that in Exchagne 2007, you can only add 1 GC through the management console. Is there a way to add more than one GC? Everytime our GC is rebooted or goes down, Exhange 2007 becomes very unhappy. This seems to be a very bad single point of failure. I have 2 GCs in our domain, but I can only point to one. Please help!

Hi, Exchange automatically detects new GCs & DCs in-site and out-of-site, this AD topology discovery process runs every 15 minutes and you can see an event in application log 2080 with source MSExchange ADAccess. Is your another GC in same AD Site? If yes then you need to verify the communication between that GC & Exchange server on port 3268 & 389. You can also verify if GC is populated correctly with below command. dsquery server -isgc -site <AD Site Name> You can increase diagnostic logging of MSExchange ADAccess\Topology to see if it has any problem. How to Change Logging Levels for Exchange Processes Additional References: Event ID 2080 from MSExchangeDSAccess Exchange Active Directory Provider found no domain controller servers

Thanks - I will give that a try.

Also, verify that the 2nd domain controller is flagged as a Global Catalog server (on the NTDS Settings for that server in the Active Directory Sites and Services console). By default, only the first domain controller you install is set up as a Global Catalog server.