MC1189663 – M365 Change Digest

One-line summary

External access tokens for actionable messages retire May 15, 2026; update integrations to use Microsoft Entra authentication to avoid failures.

Similar updates

Details

Summary

External access tokens for actionable messages will be retired by May 15, 2026, replaced by Microsoft Entra authentication to enhance security. Organizations must update integrations before this date, as messages using legacy tokens will fail. The phase-out completes by June 8, 2026.

Body (from Message Center)

Updated May 21, 2026: Phasing out to Legacy Auth Token (EAT) has been initiated and will complete by June 8th 2026. Thank you for your patience.

[Introduction]

We’re retiring the use of external access tokens for actionable messages and transitioning to Microsoft Entra-based authentication. This update enhances security and aligns with modern identity standards, providing a more robust and compliant experience for actionable messages.

[When this will happen]

This change takes effect on May 15, 2026. After this date, external access tokens will no longer be supported.

[How this affects your organization]

Who is affected:

Organizations using actionable messages that currently rely on external access tokens.

What will happen:

Actionable messages that depend on external access tokens will fail after May 15, 2026.
All integrations and workflows using actionable messages must adopt Microsoft Entra authentication.
This change improves security posture by leveraging Entra’s identity and access management capabilities.

[What you can do to prepare]

Review all actionable message implementations in your organization.
Update integrations to use Microsoft Entra authentication before May 15, 2026.

Learn more:

[Compliance considerations]

No compliance considerations identified, review as appropriate for your organization.

Raw JSON (for debugging)

Expand/collapse the full payload below.

Show/hide raw

{
  "snapshot_item": {
    "action_required_by": "2026-03-30T07:00:00Z",
    "ai_action_required_by": null,
    "ai_actions": [
      "Review actionable message usage",
      "Update integrations to Entra authentication"
    ],
    "ai_master_tags": [
      "Admin",
      "Security"
    ],
    "ai_model": "gpt-4.1",
    "ai_summary": "External access tokens for actionable messages retire May 15, 2026; update integrations to use Microsoft Entra authentication to avoid failures.",
    "ai_topics": [
      "Microsoft 365 Apps",
      "Outlook",
      "Entra"
    ],
    "category": "planForChange",
    "details_map": {
      "Summary": "External access tokens for actionable messages will be retired by May 15, 2026, replaced by Microsoft Entra authentication to enhance security. Organizations must update integrations before this date, as messages using legacy tokens will fail. The phase-out completes by June 8, 2026."
    },
    "id": "MC1189663",
    "importance": 5,
    "is_major_change": true,
    "last_modified": "2026-05-21T17:04:16Z",
    "ms_products": [
      "Microsoft 365 Apps"
    ],
    "platforms": null,
    "roadmap_ids": [],
    "services": [
      "Microsoft 365 apps"
    ],
    "severity": "normal",
    "tags": [
      "Updated message",
      "Admin impact",
      "Retirement"
    ],
    "title": "(Updated) Retirement of external access token for actionable messages \u2013 moving to Microsoft Entra authentication"
  }
}