API ReferenceEmails
Cancel scheduled email
Cancel a scheduled transactional email before it goes out. It is kept with status CANCELLED, is not billed, and a notification it held under delivery.throttle may be sent again straight away. This cannot be undone.
Authorization
ApiKeyAuth AuthorizationBearer <token>
API Key authentication. The project is automatically derived from the key.
/v1/track requires a public key (pk_*) — it is the one endpoint intended for client-side use, and a secret key is rejected there with 401.
Every other endpoint requires a secret key (sk_*) and rejects public keys with 401.
So the two key types are not interchangeable in either direction: pick the key that matches the endpoint you are calling.
In: header
Path Parameters
id*string
Email ID, as returned by POST /v1/send.
Format
uuidResponse Body
application/json
application/json
application/json
application/json
curl -X POST "https://next-api.useplunk.com/emails/497f6eca-6276-4993-bfeb-53cbbbba6f08/cancel"{
"id": "ac32f08e-c6b9-45d3-9824-a73dff1e3bbf",
"status": "SCHEDULED",
"sourceType": "TRANSACTIONAL",
"subject": "Your trial ends in 3 days",
"contact": {
"id": "cnt_abc123",
"email": "user@example.com"
},
"scheduledFor": "2026-11-01T09:00:00.000Z",
"sentAt": null,
"createdAt": "2026-10-25T10:30:00.000Z"
}{
"success": false,
"error": {
"code": "INVALID_API_KEY",
"message": "Invalid secret API key. This endpoint requires a secret key (sk_*), not a public key.",
"statusCode": 401,
"requestId": "8f14e45f-ceea-467a-9575-1f0f38e0b1c2"
},
"timestamp": "2025-01-15T10:30:00.000Z"
}{
"success": false,
"error": {
"code": "string",
"message": "string",
"statusCode": 0,
"requestId": "string",
"errors": [
{
"field": "string",
"message": "string",
"code": "string",
"received": null
}
],
"details": {},
"suggestion": "string"
},
"timestamp": "2019-08-24T14:15:22Z"
}{
"success": false,
"error": {
"code": "string",
"message": "string",
"statusCode": 0,
"requestId": "string",
"errors": [
{
"field": "string",
"message": "string",
"code": "string",
"received": null
}
],
"details": {},
"suggestion": "string"
},
"timestamp": "2019-08-24T14:15:22Z"
}