mutation SendBulkEmail($input: SendBulkEmailInput!) {
  sendBulkEmail(input: $input) {
    error {
      message
      type
      code
      fields {
        field
        message
        type
      }
    }
    skippedThreads {
      threadId
      reason
    }
  }
}

{
  "input": {
    "threadIds": [
      "id"
    ],
    "textContent": "string"
  }
}

{
  "data": {
    "sendBulkEmail": {
      "error": {
        "message": "string",
        "type": "VALIDATION",
        "code": "string",
        "fields": [
          {
            "field": "string",
            "message": "string",
            "type": "VALIDATION"
          }
        ]
      },
      "skippedThreads": [
        {
          "threadId": "id",
          "reason": "THREAD_LOCKED"
        }
      ]
    }
  }
}