Create receive connector
Step 1: Open the exchange management console
Step 2: Click on Hub Transport under Server Configuration
Step 3: In the Actions pane click on New Receive Connector…
Step 4: In the Introduction page, under Name, enter a name for the receive connector. From the drop down box under Select the intended use for this receive connector, select Internal. Click next.

Step 5: On the Remote Network Settings page, remove the default remote IP addresses and enter the IP address of the server(s) in the remote domain. Click Next.

Step 6: On the New Connector page, click New.
Step 7: On the Completion page, click Finish.
Step 8: Right click the newly created connector and select properties.
Step 9: Click the Permission Groups tab.

Step 10: Tick the box next to Anonymous Users on the permission groups tab and click Apply and OK.

Note: Repeat this step for every server who will be receiving SMTP traffic from the other organization.
Create a send connector
Step 1: Open the exchange management console
Step 2: Click on Hub Transport under Organization Configuration
Step 3: Click on the Send Connectors Tab
Step 4: In the Actions pane click on New Send Connector…
Step 5: Enter a name for the send connector. From the drop down menu under Select the intended use for this Send connector select Internal.
Step 6: In the address space pane, click on Add.
Step 7: In the SMTP Address Space window, under Address, enter the domain name for the organization mail will be routed to. Enter a cost for the send connector if applicable.
Step 8: In the network setting page, select Route mail through the following smart hosts and click Add
Step 9: In the Add smart host window, enter the IP address of the HUB transport server in the organization you will be routing the mail to and click ok.
Note: It is recommended to add multiple HUB servers in this field (if available) for redundancy.
Step 10: Click Next.
Step 11: Leave the authentication settings on their defaults. Click Next.
Step 12: In the Source server page, verify the defaults and click Next.
Note: It is recommended to add multiple source servers here (if available) for redundancy.
Step 13: In the New Connector window click New.
Step 14: In the Completion window review the results and click Finish.
Change accepted domain to internal relay
Step 1: Open the exchange management console.
Step 2: Click on Hub Transport under Organization Configuration.
Step 3: Click on the Accepted Domains tab.
Step 4: Right click the domain that needs to be changed and select properties.

Step 5: On the Properties tab, select the radio button for Internal Relay Domain.

Step 6: On the Properties tab, click OK.
Add internal relay domain for uk.sutherland.com
Step 1: Open the exchange management console
Step 2: Click on Accepted Domains under Organization Configuration
Step 3: In the Actions pane click on New Accepted Domain…
Step 4: On the New accepted domain page, enter a name and the accepted domain (for example: contoso.com). Tick the radio button for Internal Relay.

Step 5: Click New.
1.1.2.1 Create MX record for uk.toasterlabs.com
Not documented
Create external DNS records for uk.toasterlabs.com (autodiscover & mail)
Not documented

Coexistence between Exchange forests (without trusts…) —
Part 3: Preparing the UK Exchange 2007 environment

Coexistence between Exchange forests (without trusts…) —
Part 5: Preparing the GALSync Server