destination_verification_required

{
  "type": "https://developer.hostup.se/errors/destination_verification_required",
  "title": "Destination address must be verified",
  "status": 409,
  "detail": "${who}needs to confirm the verification email from Cloudflare before mail can be forwarded there. ",
  "code": "destination_verification_required",
  "instance": "/api/v2/...",
  "requestId": "req_abc123",
  "timestamp": "2026-04-27T12:00:00.000Z"
}

const response = await fetch(url, options);

if (!response.ok) {
  const problem = await response.json();

  if (problem.code === "destination_verification_required") {
    // Handle: Destination address must be verified
    console.error(problem.detail);
  }
}