HTTP 422
Invalid Idempotency-Key
The Idempotency-Key header must not exceed 255 characters.
Example response
{
"type": "https://email.squibble.ch/docs/errors/messages/send/invalid-idempotency-key/",
"title": "Invalid Idempotency-Key",
"status": 422,
"detail": "...",
"instance": "/api/v1/..."
}