A Preservation Lock in Microsoft Purview Retention Policies enforces strict compliance and prevents certain modifications to ensure data is retained according to compliance requirements.
When a Preservation Lock is applied:
1. You cannot disable or delete the policy.
2. You cannot remove locations from the policy.
3. You cannot decrease the retention period.
4. You can add locations to the policy.
5. You can increase the retention period.
You can expand the retention policy to cover additional locations (e.g., more Exchange mailboxes, SharePoint sites). You can extend the retention duration (e.g., increase from 5 years to 10 years) since this aligns with stricter compliance.