DNS Lookup Examples · Example 3 of 3 in Special Answers

Null MX: A Domain That Accepts No Mail

GEThttps://api.deepinfo.com/v1/lookup/dns

The MX record of example.com: a null MX (0 .), the way a domain says it accepts no mail.

Param: domain type
Value: example.com MX

Asks for the MX records of example.com.

The single record 0 . (priority 0, an empty host) is a "null MX" (RFC 7505): the domain declares that it accepts no e-mail. raw shows the record as MX 0 ., and values as 0 with the dot removed.

Request

curl

curl 'https://api.deepinfo.com/v1/lookup/dns?domain=example.com&type=MX' \
  -H 'apikey: YOUR_API_KEY' \
  -H 'Accept: application/json'

Python

import requests

url = "https://api.deepinfo.com/v1/lookup/dns"

params = {
    "domain": "example.com",
    "type": "MX"
}

headers = {
    "apikey": "YOUR_API_KEY",
    "Accept": "application/json"
}

response = requests.get(url, params=params, headers=headers)
response.raise_for_status()
print(response.json())

JavaScript

const url = "https://api.deepinfo.com/v1/lookup/dns?domain=example.com&type=MX";

const response = await fetch(url, {
  method: "GET",
  headers: {
    "apikey": "YOUR_API_KEY",
    "Accept": "application/json"
  },
});

const data = await response.json();
console.log(data);

package main

import (
	"fmt"
	"io"
	"net/http"
)

func main() {
	req, err := http.NewRequest("GET", "https://api.deepinfo.com/v1/lookup/dns?domain=example.com&type=MX", nil)
	if err != nil {
		panic(err)
	}
	req.Header.Set("apikey", "YOUR_API_KEY")
	req.Header.Set("Accept", "application/json")

	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()

	body, err := io.ReadAll(res.Body)
	if err != nil {
		panic(err)
	}
	fmt.Println(string(body))
}

Java

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

public class Main {
    public static void main(String[] args) throws Exception {
        HttpRequest request = HttpRequest.newBuilder()
            .uri(URI.create("https://api.deepinfo.com/v1/lookup/dns?domain=example.com&type=MX"))
            .header("apikey", "YOUR_API_KEY")
            .header("Accept", "application/json")
            .GET()
            .build();

        HttpResponse<String> response = HttpClient.newHttpClient()
            .send(request, HttpResponse.BodyHandlers.ofString());

        System.out.println(response.body());
    }
}

using System;
using System.Net.Http;

using var client = new HttpClient();

var request = new HttpRequestMessage(HttpMethod.Get, "https://api.deepinfo.com/v1/lookup/dns?domain=example.com&type=MX");
request.Headers.Add("apikey", "YOUR_API_KEY");
request.Headers.Add("Accept", "application/json");

using var response = await client.SendAsync(request);
Console.WriteLine(await response.Content.ReadAsStringAsync());

PHP

<?php

$curl = curl_init();

curl_setopt_array($curl, [
    CURLOPT_URL => 'https://api.deepinfo.com/v1/lookup/dns?domain=example.com&type=MX',
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'apikey: YOUR_API_KEY',
        'Accept: application/json',
    ],
]);

$response = curl_exec($curl);

if ($response === false) {
    throw new RuntimeException(curl_error($curl));
}

echo $response . PHP_EOL;

Ruby

require 'net/http'
require 'uri'

uri = URI('https://api.deepinfo.com/v1/lookup/dns?domain=example.com&type=MX')

request = Net::HTTP::Get.new(uri)
request['apikey'] = 'YOUR_API_KEY'
request['Accept'] = 'application/json'

response = Net::HTTP.start(uri.hostname, uri.port, use_ssl: uri.scheme == 'https') do |http|
  http.request(request)
end

puts response.body

Response

200 OK · application/json

Response Body

{
  "fqdn": "example.com",
  "requested_types": [
    "MX"
  ],
  "responses": [
    {
      "type": "MX",
      "conn_status": "success",
      "rcode": "NOERROR",
      "raw": "example.com. 300 IN MX 0 .",
      "values": [
        "0 "
      ],
      "server": "8.8.8.8"
    }
  ],
  "servers": [
    "8.8.8.8"
  ],
  "check_date": "2026-09-24T07:48:35Z"
}

Content-Type: application/json
ratelimit-limit: 100000
ratelimit-remaining: 99981
ratelimit-reset: 25
x-ratelimit-limit-minute: 100000
x-ratelimit-remaining-minute: 99981
deepinfo-request-id: 5f0c6a8e-1b2d-4c3e-9f4a-7b8c9d0e1f2a

Request

What this example sends. Every parameter is documented on DNS; the exact request is in the code panel.

Parameter	Value
`domain`query	`example.com`
`type`query	`MX`

Reference updated September 24, 2026

Request

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