Ensure that you have purchased and configured SPF Authentication in the Portal and our support team have confirmed to you that the service is active prior to configuring Office 365 for outbound relay. 

1. Log in to Office 365 Admin Center.

2. Select Admin > Exchange.

3. The Exchange Admin Center is displayed.

4. Select Mail Flow > Connectors and create a new Connector:

5. Click Next.

6. Enter the following:

7. Click Next.

8. Select Only when email messages are sent to these domains.

9. Click the + icon to add the recipient domains that should use this connector.

10. Enter a value of * to route all outbound emails through the new smarthost.

11. Click OK and Next.

12. Select Route Email Through These Smart Hosts.

13. Click the + icon to add the smart hosts.

14. To retrieve the text you need to insert into the smart host, sign in to the DuoCircle Portal.

        a. Copy and paste the text in Outbound Relay Host. This is the text you will need to enter into              the smart host webpage. For example, outbound.mailhop.org

        b. Paste the text into the field and click Save.

15. Click Next.

16. Select the following options:

        Always use Transport Layer Security (TLS) to Secure the Connection

        Any digital certificate, including self-signed certificates.

17. Click Next to verify your settings. 
(This step may fail but the connector will work correctly)

18. Click Next and add an email address of a recipient from a domain external to your organization.

19. Click Validate.

20. Once Office 365 has successfully validated your settings, click Save. 

Disable or remove any other Outbound Send Connectors that were previously used. Failure to do this means your outbound email still uses these older send connectors, and is not routed through the new connector. Any send connectors used for other purposes (e.g archiving) may still be required to be enabled. If in doubt, contact Support.

It may take up to 24 hours for these changes to propagate in the Microsoft system.