Just curious at this stage, but can two Exchange servers sync-up across a remote distance, like another continent, to run two offices sharing the same domain name / email address?
Also, would there be a problem if one of the servers was an SBS box?
SnapOverflow
You can have Exchange servers in different continents serving the same domain. That's not an issue at all. The only issue that would be more complex to setup is if you're looking to do DR replication of all the data between the two, which requires you have enough bandwidth to ship the logs over
And yes, you can add an Exchange server to an environment with SBS so long as it's in the same domain. You can't have multiple AD domains with SBS.
The 2 exchange servers will be able to share the same domain. SBS will already be setup to go. Point your MX records to this box. Do a basic install on the second Exchange server (Mailbox, Hub Transport, and Client Access roles). Make sure you have a domain controller with global catalog at the second site. Also make sure your sites are setup correctly in Active Directory Sites and Services. Any messages that come in destined for mailboxes at the second site will be passed between the hub transport roles.
You cannot have full mailbox replication. High availability features like CCR require Exchange Enterprise and Windows Enterprise so will not work with SBS.