Email message complained
Triggered when a recipient marks an outbound email as spam (recipient is added to the suppression list)
Headers
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.
Unix seconds when this attempt was sent. Reject anything older than five minutes.
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
Example payload
{
"id": "whev_abc123",
"object": "event",
"type": "email_message.complained",
"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.