curl --request GET \
  --url https://api.migma.ai/v1/emails/previews/{previewId}/status \
  --header 'Authorization: Bearer <token>'

{
  "success": true,
  "data": {
    "previewId": "<string>",
    "status": "<string>",
    "metadata": {
      "requestedDevices": 123,
      "completedDevices": 123,
      "failedDevices": 123
    }
  }
}