API & Integrations - Retention Adjustment API - Apr 2026

Service Update

Availability	April 7th, 2026
Product(s)	Cloud Archive for Email
Who's affected	Administrators and API integrators using Cloud Archive for Email with API 2.0 applications

Overview

Mimecast is pleased to announce the release of the Retention Adjustment API endpoint, a new addition to the Data Retention section of the Mimecast API 2.0 Developer Portal. 

This endpoint enables you to programmatically create Retention Adjustment requests for archived messages, supporting automated compliance, Right to be Forgotten (RTBF), and Data Subject Access Request (DSAR) workflows.

What's changing

A new Retention Adjustment endpoint is now available under the Data Retention product area on the Mimecast API 2.0 Developer Portal. This endpoint allows callers to programmatically modify the retention period of individual archived messages, enabling you to reduce, extend (up to the account’s Maximum Retention setting), or immediately expire messages via API, rather than through the Mimecast Administration Console.

Key capabilities:

• Automated RTBF & DSAR workflows: Programmatically initiate purge or Retention reduction requests for identified messages as part of data subject request processing, removing the need for manual action in the Mimecast Administration Console.
• Compliance automation: Adjust Retention periods based on regulatory requirements or internal policy changes, integrating retention lifecycle management into external Governance, Risk, and Compliance (GRC), eDiscovery, or Legal Hold platforms.
• Bulk Retention adjustments: Process Retention changes for messages identified through case-based searches at scale, rather than requiring individual manual adjustment.
• API 2.0 authentication: Uses OAuth 2.0 (Client ID / Client Secret) authentication, consistent with all other API 2.0 endpoints.

Retention Adjustments cannot extend a message’s Retention period beyond the account’s Maximum Retention setting.
Messages that have exceeded their Retention period will expire; however, messages on Litigation Hold will not be deleted and will remain discoverable via Case Review.
Mimecast will honor all requests sent to this endpoint. It is the responsibility of the requestor to ensure the correct message identifier and retention day value are submitted. If an incorrect message ID is sent with a retention value of 0, the message will be expired.

Recommended actions

No immediate action is required. This is a new API endpoint that is available if you wish to integrate Retention Adjustment workflows into your existing tooling.

To begin using this endpoint, you will need to:

• Ensure your Account has an active Cloud Archive for Email subscription.
• Ensure you have a Mimecast Administration Console role with Super Administrator permissions.
• Raise a Support case to enable the Retention Adjustment API Setting on your account; this must be done before using this endpoint.
• Set up a registered API 2.0 application with the the Data Retention product enabled. See Managing API 2.0 Applications

For full endpoint documentation, including request and response schemas, visit the Data Retention section of the Mimecast API 2.0 Developer Portal.
For questions or assistance, please contact your Customer Support Manager (CSM), or raise a Support case.

See Also...

• API & Integrations - Managing API 2.0 Applications
• Mimecast API 2.0 Developer Portal