You want to configure a new inbound route for email delivery in Email Security.cloud.
Inbound Routes will accept a value of either a public IP address or Fully Qualified Domain Name (FQDN). The new route can be configured as either the Default route that will be used for all of your domains or as a Custom route specific to a singular domain.
For hosted cloud email service providers Google G Suite or Microsoft Office 365 Exchange: Add the G Suite Gmail FQDN (eg. aspmx.l.google.com) or Office 365 Exchange FQDN (eg. domain-com.mail.protection.outlook.com), provided by Google or Microsoft, respectively, as the route that can be used for your hosted email domains.
When you add a route, the route must pass a number of automated technical checks before we can register the route for your organization's use. These checks may include running an open relay test and cross-referencing the route against reputable Public Blocklists (PBL). After you add an inbound route, the "Requested Inbound Routes" section lists the routes queued for testing. If the tests pass, you will receive an email notification alerting you of the same and the route will appear under Inbound Routes. If the tests fail, you will receive an email notification and the route will be removed. The process must be started again after addressing the issues indicated in the failed tests email notification.