Delete an extra smtp domain

{
  "type": "object",
  "properties": {
    "domainName": {
      "type": "string"
    },
    "domain_name": {
      "type": "string",
      "description": "Mail zone domain name."
    },
    "hostname": {
      "type": "string",
      "description": "Smtp domain name."
    }
  },
  "required": [
    "domainName",
    "domain_name",
    "hostname"
  ],
  "additionalProperties": false
}