EMAIL-023: Per-user outbound gateways disabled (GWS.GMAIL.12.1)
- Platform
- Google Workspace
- Category
- Advanced Threat Protection
- Severity
- Medium
- Zero Trust pillar
- Data (weight 2)
- Golden fixtures
- 4
- Branch coverage
- Observed: fixtures prove the verdicts they exercise
- Provenance
- baseline
What it checks
SCuBA GWS.GMAIL.12.1 requires that per-user outbound gateways be disabled. When enabled, users can route outbound mail through their own external SMTP servers, bypassing the organization's mail security controls and creating a data-exfiltration and spoofing path. This check reads the gmail.per_user_outbound_gateway policy from the Cloud Identity Policy API and flags any organizational unit where external SMTP routing is allowed. When the policy is not returned the result is Not Assessed.
Recommended value
Per-user outbound gateways (external SMTP) disabled for all organizational units
Remediation
In the Google Admin console under Apps > Google Workspace > Gmail > Routing, ensure per-user outbound gateways are not permitted so users cannot route mail through external SMTP servers. Keep outbound routing centralized through approved gateways only.
Fixture-proven verdicts
Every verdict below is proven by a golden fixture in the module's gating test suite. This table derives from the last green run; it cannot be edited by hand.
| Scenario | Expected verdict |
|---|---|
| clean | PASS |
| known-bad | FAIL |
| no-data | Not Assessed |
| no-policy | Not Assessed |
Framework mappings
- CISA SCuBA
- GWS.GMAIL.12.1v1
- NIST SP 800-53
- AC-4, SC-7, SI-8