Click CONFIGURATION ⇒ POLICIES

Click CREATE POLICY

Select "Email Routing", enter an arbitrary policy name, and click "CREATE".

Click Manage for Email Routing Configuration.

Select Out of Band (OOB). Select BCC source and click SAVE.

Click CONFIGURATION ⇒ DOMAINS

Click on PROVISION DOMAINS

Select "Out of Band (OOB)" as the domain mode, enter the target email domain, and select the policy you just created as the Email routing Policy.

From the list of domains, click the domain you just created.

Please BCC forward to the following email address from the forwarding mail server.