Step 1: Write the policy intent
Begin with one sentence that business, privacy, security, and platform owners can approve:
Prevent customer identity records from being sent to unauthorized external recipients through Gmail or shared outside approved Drive locations, while allowing documented partner workflows.
Record the owner, legal or contractual basis, in-scope population, success measure, exception approver, and review date.
Step 2: Choose locations and scope deliberately
Select only the Workspace locations involved in the scenario. Separate Gmail and Drive rules when they need different conditions, user guidance, or actions. Define users, groups, organizational units, domains, and external-sharing states explicitly.
Avoid starting with the broadest possible scope. A smaller pilot makes it easier to identify false positives, missing business exceptions, and unexpected user impact.
Step 3: Define and test detection
Choose the signal that represents the data:
- predefined or custom data detectors
- exact values or approved reference data, where supported
- keywords and regular expressions with proximity or context
- combinations of content, volume, recipient, sharing state, and user context
Test true positives, near-misses, templates, signatures, public information, and approved business documents before enabling a hard restriction.
Step 4: Design an action ladder
Use increasing response severity:
- Low confidence or discovery: Audit and measure.
- Moderate confidence external sharing: Warn the user and allow a documented justification where appropriate.
- High confidence or high-volume transfer: Restrict, block, quarantine, or alert according to the approved scenario.
- Approved workflow: Allow a tightly defined exception and retain evidence.
Every exception needs an owner, reason, scope, and expiry date. Avoid broad domain or organizational exclusions that quietly bypass the original objective.
Step 5: Write useful user guidance
Explain what the user attempted, why it needs attention, what approved alternative is available, and how to request help. Do not reveal matched sensitive values in the message.
For example:
This message appears to contain customer identity data and cannot be sent to this external recipient. Use the approved partner channel or contact the Data Protection team if this transfer is required.
Keep the language calm and actionable. Measure whether users understand the guidance and whether approved workflows are practical.
Step 6: Deploy progressively
Use a staged rollout:
Phase A: Observe
Review matches, affected users, locations, false positives, and expected business exceptions without disrupting work.
Phase B: Pilot guidance
Use a representative group. Provide warnings or guidance where supported and collect feedback on timing, clarity, and legitimate workflows.
Phase C: Limited enforcement
Enforce high-confidence scenarios for a controlled population. Ensure service desk and exception owners are ready.
Phase D: Broader enforcement
Expand only after detection, user guidance, evidence, and response workflows are stable. Document rollback criteria.
Step 7: Test end to end
Test:
- matching and non-matching messages and files
- internal, external, approved, and prohibited destinations
- Gmail attachments and Drive links
- individual and shared-drive access
- warning, justification, block, quarantine, and exception behavior
- alert creation, investigation, and audit records
- propagation delay after changes
- browser, desktop, mobile, and managed-device behavior where in scope
Use synthetic test data and document the expected result before each test.
Step 8: Document the production policy
Keep a concise record of intent, scope, detectors, thresholds, actions, exceptions, alerts, test evidence, deployment stage, dependencies, owner, and review date.
Primary Google sources
- Prevent data leaks in email and attachments — Gmail and other Workspace DLP rule configuration.
- Create DLP for Drive rules and custom content detectors — Drive rule conditions, custom detectors, and audit-only tests.
- Create and manage activity rules — activity-rule notifications and administrator controls.
The next part covers ongoing Workspace operations and continuous improvement.