Hi,
Nothing special needed. Just set the smart host to point to the FOPE network. If you want all outbound mail to be filtered by the FOPE network, you can remove the other send connectors that you have.
If you will be sending high volumes of email, the following article might be relevant:
http://technet.microsoft.com/en-us/library/ff715282.aspx
If the server is sending outbound e-mail through the Hosted Filtering service, we also recommend that the server be configured to send no more than 50 messages per connection and to use fewer than 50 concurrent connections. Under normal circumstances, these
settings will help ensure that the server has smooth and continuous data transfer to the service.
Here's a link on how to set those limits:
http://technet.microsoft.com/en-us/library/bb123514.aspx
and finally a link for setting the smart host:
http://technet.microsoft.com/en-us/library/bb629503.aspx
Kemper - MSFT