Email

Email message failed

Triggered when an outbound email fails to send

postWebhookemail_message.failed

Headers

webhook-idstring required

The event's id, identical on every retry and equal to id in the body. Store it to ignore a delivery you have already handled.

webhook-timestampstring required

Unix seconds when this attempt was sent. Reject anything older than five minutes.

webhook-signaturestring required

v1,<signature>, per the Standard Webhooks specification: the base64 HMAC-SHA256 of <webhook-id>.<webhook-timestamp>.<raw request body>, keyed with the bytes your whsec_ secret encodes. Verify it with a Standard Webhooks library before processing the event.

Payload

idstring required

Unique identifier for this webhook event

object'event' required
type'email_message.failed' required

The event type

created_atstring date-time required

ISO 8601 timestamp of when the event was created

api_versionstring required

API version used to generate the payload

Example payload

{
  "id": "whev_abc123",
  "object": "event",
  "type": "email_message.failed",
  "created_at": "2025-01-15T10:30:00Z",
  "api_version": "v1"
}

Response

Return any 2xx status within 5 seconds to acknowledge receipt.

Changes

Webhooks have no change history: a webhook is keyed by its event name rather than a path and method, so no recorded change can name it.