KT-CT-14215

{
  "errors": [
    {
      "message": "Sent at datetime is in the future.",
      "extensions": {
        "errorType": "VALIDATION",
        "errorDescription": "The sentAt datetime must not be in the future. External messages represent messages that have already been sent.",
        "errorCode": "KT-CT-14215"
      }
    }
  ]
}