IT Support Needed – Google Workspace/Proofpoint Essentials Outbound Relay Issue

We need an IT expert in Google Workspace/Proofpoint/email deliverability Environment: Client is running Google Workspace (Business tier) with multiple secondary domains managed under a single Google Workspace account DNS is split across multiple providers (Wix, Bluehost, GoDaddy) No Microsoft 365 involvement What has been implemented successfully: Proofpoint Essentials Advanced+ provisioned and configured for the primary domain Domain verified in Proofpoint, mail relay active, DKIM signing active MX records updated in DNS to route inbound through Proofpoint Primary delivery destination set to ASPMX.L.GOOGLE.COM & smtp.google.com for new domain registrations SPF record updated to include both Google and Proofpoint DKIM TXT record added to DNS Inbound gateway configured in Google Workspace with full Proofpoint IP ranges Google Apps hosted service enabled under Sending Servers in Proofpoint Inbound mail filtering through Proofpoint is fully operational Where we are stuck: The outbound relay through Proofpoint is not functioning. The outbound smarthost is configured in Google Workspace pointing to outbound-us1.ppe-hosted.com port 587 with TLS. When enabled, outbound mail is rejected by Proofpoint with two alternating errors: 450 4.3.2 - Client host rejected: Try again later FAILED_PRECONDITION: read error (104): Connection reset by peer Proofpoint support has indicated this is a Google Workspace side issue. Additional complication: The Google Workspace Admin Console is throwing a "host settings update failed" error on any attempt to modify Gmail Hosts or Routing settings. This affects all Super Admin accounts on the tenant. The Outbound Gateway field remains stuck pointing to outbound-us1.ppe-hosted.com and cannot be cleared through the UI. This is believed to be a Google Admin Console backend bug specific to this tenant. Current workaround: Outbound mail is currently bypassing Proofpoint and routing directly through Google. Inbound is fully protected through Proofpoint. Client is operational but outbound encryption and DLP policies are not active. What we need: Resolve the "host settings update failed" error in Google Workspace Admin Console: likely requires Google Admin SDK API access or direct Google backend intervention Clear the stuck Outbound Gateway field Confirm and restore outbound mail flow through Proofpoint's smarthost Verify outbound encryption policies are functioning end to end Ideal candidate: Strong experience with Google Workspace Admin SDK, Gmail routing configuration, and Proofpoint Essentials in a Google Workspace environment. Google Workspace certified preferred. We are willing to work with candidate to bring client fully online with Proofpoint. This will be a collaborative effort with the candidate to ensure client services are all working as intended, with both inbound and outbound mail being able to deliver successfully through Proofpoint.