Mail Event

trigger.outlook_event

TriggerEmailconnection requiredruns in-engine

Creates a Microsoft Graph change-notification subscription on publish, renews it before it expires, and starts one run per notification.

Start a run when a message is created, updated or deleted in an Outlook / Microsoft 365 mailbox.

Ask about Outlook / Microsoft 365 All Outlook / Microsoft 365 nodes Provider API docs ↗

Connection

Required: Yes — the node will not save without one
Auth type: OAuth 2.0
Providers: Outlook / Microsoft 365
Secret shape: the Microsoft {client_id, client_secret, refresh_token} triple
Config it needs: tenant
Resolved by: config.connection_id, else node.connection_id
Note: The refresh token needs read access to what it subscribes to — Mail.Read for messages, Calendars.Read for events, Contacts.Read for contacts. Graph refuses a subscription for a resource the token cannot read. Publishing also needs MANTLE_APP_PUBLIC_BASE_URL set to an https URL Graph can reach and that answers its validation probe within ten seconds.

Configuration

2 fields, none required. A dotted path is a nested object and name[] an array of objects — the editor renders the same tree.

Field	Type	Required	Default	Constraints	Example
resource The Graph resource to watch, e.g. me/mailFolders('inbox')/messages for the inbox, me/messages for the whole mailbox, or me/events / me/contacts for the calendar and contacts. Leave it blank for the inbox.	string	No	me/mailFolders('inbox')/messages	—	me/mailFolders('inbox')/messages
change_types Which changes start a run. 'created' alone means new mail; adding 'updated' also fires when a message is read, flagged, moved or categorised, which is far noisier than most workflows expect.	array	No	["created"]	1–3 characters; array of string	—

Example configuration

Every value below is the contract’s own example or default — nothing invented.

{
  "change_types": [
    "created"
  ],
  "resource": "me/mailFolders('inbox')/messages"
}

Output

One shape.

graph notification

One Microsoft Graph change notification, flattened. Graph sends the id of what changed, not its content.

Extra keys beyond the ones listed can appear.

Field	Type	Example
notification_id Graph's own id for this notification, and the run's idempotency key when it is present. Graph retries a delivery for up to four hours, reusing it, so a retry joins the run it already started.	string	lsgTZMr9KwAAA
change_type What happened: created, updated or deleted. Branch on this when the trigger subscribes to more than one.	string	created
resource The Graph path of the thing that changed, as Graph writes it.	string	Users/8ee44408-0679-472c-bc2a-692812af3437/Messages/AAMkAGVmMDEz
resource_id Id of the message (or event, or contact). This is a BASIC notification: Graph sends the id, not the mail — read it back with the Outlook nodes, and expect a 404 when change_type is deleted.	string	AAMkAGVmMDEz
resource_type Graph's type marker for it, e.g. #Microsoft.Graph.Message.	string	#Microsoft.Graph.Message
etag The version of the resource this notification is about. It changes with the resource, which is what makes an update distinguishable from the update before it.	string	—
subscription_id The Graph subscription that delivered this — constant while the workflow stays published, across renewals.	string	7f105c7d-2dc5-4530-97cd-4e7ae6534c07
subscription_expires_at When that subscription expires, as Graph reports it. The renewal sweep extends it well before this; it is here for diagnosis.	string	—
tenant_id The Microsoft 365 directory the change happened in — NOT the Mantle tenant.	string	—
payload Graph's notification exactly as it arrived, minus clientState, which is the shared secret the delivery was verified against.	object	—

{
  "change_type": "created",
  "etag": "W/\"CQAAABYAAADkrWGo7bouTKlsgTZMr9KwAAAUWRHf\"",
  "notification_id": "lsgTZMr9KwAAA",
  "payload": {
    "changeType": "created",
    "id": "lsgTZMr9KwAAA",
    "resource": "Users/8ee44408-0679-472c-bc2a-692812af3437/Messages/AAMkAGVmMDEz",
    "resourceData": {
      "@odata.type": "#Microsoft.Graph.Message",
      "id": "AAMkAGVmMDEz"
    },
    "subscriptionId": "7f105c7d-2dc5-4530-97cd-4e7ae6534c07"
  },
  "resource": "Users/8ee44408-0679-472c-bc2a-692812af3437/Messages/AAMkAGVmMDEz",
  "resource_id": "AAMkAGVmMDEz",
  "resource_type": "#Microsoft.Graph.Message",
  "subscription_expires_at": "2026-09-17T09:00:00Z",
  "subscription_id": "7f105c7d-2dc5-4530-97cd-4e7ae6534c07",
  "tenant_id": "84bd8158-6d4d-4958-8b9f-9d6445542f95"
}

Notes

Publishing creates the subscription in Microsoft Graph; unpublishing, disabling or archiving deletes it. A workflow that is off is off at Graph too.
A Graph subscription on Outlook mail expires after at most seven days. Mantle renews it in place well before that, so the id and the shared secret survive; nothing has to be re-authorised.
This is a BASIC notification: Graph sends the id of what changed, not the message. Follow the trigger with an Outlook read node.
Graph refuses a second subscription with the same resource and change types on the same mailbox with a 409, so two published workflows cannot watch the same folder for the same change through one connection.
A delivery is authenticated by the clientState Graph echoes back, not by a signature — Graph does not sign notifications. That value is a secret and is stripped from the emitted payload.
Graph gives a delivery three seconds before it counts as slow and retries for up to four hours; every retry carries the same notification id, so a retry joins the run it already started.

See Mail Event run in a workflow.

In a technical demo we add the Outlook / Microsoft 365 connection, drop the node on the canvas and let Workflow Health pre-flight it before the first real run.

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