Graph Task Subscriptions is not sending notification if the task is created through Outlook Desktop

Question

Graph Task Subscriptions is not sending notification if the task is created through Outlook Desktop

Wei Hong 5

I have created the a subscription for monitor the default tasks. However, it is only sending notification for tasks created through api. If the task is created through Outlook Desktop App, no notification received. I also test the event subscription, somehow the event notification is working perfectly without issues.

Here is the subscription and task object I used:

{
    "@odata.context": "https://graph.microsoft.com/beta/$metadata#subscriptions",
    "value": [
        {
            "id": "2c1fc264-22db-49e3-b1d9-466f3e356a41",
            "resource": "me/todo/lists/AAMkADRhZGQyZmQ2LTAxZTktNGUxYi04NDZjLTI0ZTVjYzUzMzlhMQAuAAAAAABPZ0FdwloCQ4H1MY8CRko9AQCxro6KkQdUSL8vkwYCuGCGAAAAAAESAAA=/tasks",
            "applicationId": "d705a3d0-78a5-4d66-821c-052cd000c238",
            "changeType": "created,updated,deleted",
            "clientState": null,
            "notificationUrl": "https://www.jobssos.com/connect/joswebhook.jsp?teamid=1&recruiterId=115548",
            "notificationQueryOptions": null,
            "notificationContentType": "application/json; charset=utf-8",
            "lifecycleNotificationUrl": "https://www.jobssos.com/connect/joswebhook.jsp?teamid=1&recruiterId=115548",
            "expirationDateTime": "2026-06-04T12:55:53Z",
            "creatorId": "de306015-cc84-43a0-8ca6-0daef779a832",
            "includeResourceData": null,
            "latestSupportedTlsVersion": "v1_2",
            "encryptionCertificate": null,
            "encryptionCertificateId": null,
            "notificationUrlAppId": null,
            "resourceChangeType": null
        },

https://graph.microsoft.com/v1.0/me/todo/lists/AAMkADRhZGQyZmQ2LTAxZTktNGUxYi04NDZjLTI0ZTVjYzUzMzlhMQAuAAAAAABPZ0FdwloCQ4H1MY8CRko9AQCxro6KkQdUSL8vkwYCuGCGAAAAAAESAAA=/tasks?$top=5&$orderby=lastModifiedDateTime%20desc/tasks

    "value": [
        {
            "@odata.etag": "W/\"sa6OipEHVEi/L5MGArhghgAHxrRZxA==\"",
            "importance": "normal",
            "isReminderOn": false,
            "status": "notStarted",
            "title": "Created In Outlook Desktop App",
            "createdDateTime": "2026-06-02T14:49:28.0099497Z",
            "lastModifiedDateTime": "2026-06-02T14:49:28.1190303Z",
            "hasAttachments": false,
            "categories": [],
            "id": "AAMkADRhZGQyZmQ2LTAxZTktNGUxYi04NDZjLTI0ZTVjYzUzMzlhMQBGAAAAAABPZ0FdwloCQ4H1MY8CRko9BwCxro6KkQdUSL8vkwYCuGCGAAAAAAESAACxro6KkQdUSL8vkwYCuGCGAAfLcxenAAA=",
            "body": {
                "content": "",
                "contentType": "text"
            }
        },

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4 answers

Your answer

Answer 1

David S 0

Microsoft Service Health issue MO1331639 from Jun 2, 2026, 9:55 AM EDT indicates "Users are unable to receive webhook-based task notifications in Microsoft To Do." and a fix has not yet been released. The details are at https://admin.cloud.microsoft/?#/servicehealth/:/alerts/MO1331639

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Answer 2

In case anyone else has this problem, Microsoft has a service health issue, MO1331639, at https://admin.cloud.microsoft/?#/servicehealth/:/alerts/MO1331639 that indicates Graph API subscriptions for Microsoft To Do items have been failing to send since June 2nd, that they have a fix written as of the 10th, and that as of yesterday, they have no ETA on when they're ever going to actually push the fix out, but not to expect any Graph API Subscriptions about To Do tasks until someday when they get around to fixing it. You'll need to sign in for the official notification, but most it is here for reference:

Issue ID: MO1331639

Affected services: Microsoft 365 suite

Status: Service degradation

Issue type: Advisory

Start time: Jun 2, 2026, 9:55 AM EDT

User impact Users are unable to receive webhook-based task notifications in Microsoft To Do.

More info This issue may affect any webhook-based task notification in Microsoft To Do:

Any webhook notification delivery to your organization's registered notificationUrl endpoints that was setup using Microsoft Graph: https://learn.microsoft.com/en-us/graph/change-notifications-with-resource-data?tabs=csharp

Any automation or workflow that depends on receiving real-time task change callbacks If your organization relies on webhook notifications for task automation:

Consider temporary polling via GET requests to /me/todo/lists/{listId}/tasks as a workaround: https://learn.microsoft.com/en-us/graph/api/resources/todo-overview?view=graph-rest-1.0

Scope of impact Your organization is impacted by this event, and this issue may affect any user within your organization.

Current status Jun 18, 2026, 3:15 PM EDT We're continuing to internally validate the fix and we'll aim to provide an estimated deployment timeline as soon as it's available. Next update by: Monday, June 22, 2026 at 8:00 AM EDT

History of updates Jun 10, 2026, 6:08 AM EDT We've completed the development of the long-term fix to restore webhook-based task notifications in Microsoft To Do, and we're now conducting a period of internal testing to ensure the fix produces the expected resolution. Once complete, we'll begin deploying the fix to the affected infrastructure.

Jun 2, 2026, 9:55 AM EDT We've identified a configuration issue affecting webhook-based task notifications in Microsoft To Do. We're developing a long-term fix to restore functionality, and we'll provide additional updates as this progresses.

Answer 3

Ward Wilmsen 0

Same issue here, even if adding private tasks through the new Planner UI the subscription notifications are not triggered anymore. Looks more like a general bug / issue to me since the new Planner UI update.

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Answer 4

Outlook tasks created via the classic Outlook tasks API are no longer a supported source for change notifications. The Outlook tasks API (/me/outlook/tasks) is deprecated and stopped returning data on August 20, 2022. The guidance is to use Microsoft To Do tasks (/me/todo/...) instead.

The subscription shown targets a To Do task list (me/todo/lists/{id}/tasks). Notifications are only raised for changes that flow through the To Do task backend. Tasks created in Outlook Desktop that still use the old Outlook tasks store will not generate Microsoft Graph To Do (todoTask) change notifications, even though they may appear in the UI.

To receive notifications consistently:

Use To Do tasks instead of the deprecated Outlook tasks API:
- Create and manage tasks via the To Do API (/me/todo/lists/{todoTaskListId}/tasks).
- Ensure the Outlook client is using To Do / Microsoft 365 tasks (not the legacy Outlook tasks store) so that tasks are backed by the same To Do service.
Keep the subscription valid:
- Ensure the subscription is renewed before expirationDateTime using PATCH /subscriptions/{id} with a new expirationDateTime.
If tasks are still being created via the deprecated Outlook tasks API (/me/outlook/tasks), move the workflow to To Do tasks, because the Outlook tasks API is deprecated and not supported for production or for new integrations.

References: