MailboxValidator Free Email Checker

mailboxvalidator · Communication

Communication No Auth Free & Open email

The MailboxValidator Free Email Checker checks if a single email address is from a free email provider and returns the results in either JSON or XML format. Refer to https://www.mailboxvalidator.com/api-email-freem for further information.

Authentication

No authentication requiredFree to use with no key needed.

Sample Requests

GET GET /v1/email/free

The Free Email Checker API does validation on a single email address and returns if it is from a free email provider in either JSON or XML format.

https://api.apis.guru/v2/specs/mailboxvalidator.com/checker/1.0.0/v1/email/free?key=YOUR_API_KEY&email=[email protected]&format=json

Hover any highlighted part to learn what it does

curl -X GET "https://api.apis.guru/v2/specs/mailboxvalidator.com/checker/1.0.0/v1/email/free?key=YOUR_API_KEY&email=test%40example.com&format=json"

import requests
params = {
    "key": "YOUR_API_KEY",
    "email": "[email protected]",
    "format": "json"
}
response = requests.get(
    "https://api.apis.guru/v2/specs/mailboxvalidator.com/checker/1.0.0/v1/email/free",
    params=params,
)
print(response.json())

const url = new URL('https://api.apis.guru/v2/specs/mailboxvalidator.com/checker/1.0.0/v1/email/free');
url.searchParams.set('key', 'YOUR_API_KEY');
url.searchParams.set('email', '[email protected]');
url.searchParams.set('format', 'json');

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

package main

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

func main() {
	baseURL, _ := url.Parse("https://api.apis.guru/v2/specs/mailboxvalidator.com/checker/1.0.0/v1/email/free")
	q := baseURL.Query()
	q.Set("key", "YOUR_API_KEY")
	q.Set("email", "[email protected]")
	q.Set("format", "json")
	baseURL.RawQuery = q.Encode()
	targetURL := baseURL.String()
	req, _ := http.NewRequest("GET", targetURL, nil)

	client := &http.Client{}
	resp, _ := client.Do(req)
	defer resp.Body.Close()
	body, _ := io.ReadAll(resp.Body)
	fmt.Println(string(body))
}

require "net/http"
require "json"

uri = URI("https://api.apis.guru/v2/specs/mailboxvalidator.com/checker/1.0.0/v1/email/free")
uri.query = URI.encode_www_form({
  "key" => "YOUR_API_KEY",
  "email" => "[email protected]",
  "format" => "json"
})

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = uri.scheme == "https"

req = Net::HTTP::Get.new(uri)

res = http.request(req)
puts JSON.parse(res.body)

<?php
$url = "https://api.apis.guru/v2/specs/mailboxvalidator.com/checker/1.0.0/v1/email/free?" . http_build_query([
    "key" => "YOUR_API_KEY",
    "email" => "[email protected]",
    "format" => "json"
]);
$opts = ["http" => [
    "method" => "GET",
]];
$ctx = stream_context_create($opts);
$res = file_get_contents($url, false, $ctx);
print_r(json_decode($res, true));

Postman Setup Guide

Get Postman ↗

See official documentation for authentication and setup.

What can you build with MailboxValidator Free Email Checker?

MailboxValidator Free Email Checker is a Communication API. Developers commonly use communication APIs for:

sending SMS alerts and notifications
building in-app chat and messaging features
automating email sequences and transactional emails
creating voice bots and IVR systems
verifying phone numbers at signup

No authentication required. This API is open — no signup or key needed. Ideal for quick prototypes and public-facing features. MailboxValidator Free Email Checker is free to use, making it a low-risk choice to experiment with.

New to APIs? Read our beginner's guide · Learn about API keys · What is REST?

Open documentation ↗