I am running Windows 2003 SP2 on two servers. They are both domain controllers, and both have a copy of the global catalog. Replication works just fine. I added Exchange 2003 to one of them. Forestprep and Domainprep ran without errors. However, when I look at a user under Active Directory Users and Computers I see all of the tabs dealing with Exchange on the server containing Exchange, but none of the tabs for Exchange when I look at AD on the other server. Obviously the extensions to the schema didn't replicate to the other server. What now? Do I run Forestprep and Domainprep on the other server too? Thanks.

You need to install Exchange Management Tools to see the Exchange tabs while opening properties of any mail/mailbox enabled object in other server. Run Exchange 2003 setup and select only Management Tools to install on it.

That got it! Gracias.