Developer API Documentation

Overview

The ListEmailCheck API allows developers to perform real-time verification of email addresses during user registration, checkout flows, lead collection forms, and batch processing pipelines.

Authentication

Public web verifications are available directly through the single-email verification endpoint. Authenticated requests utilize session-based authentication or API key header verification:

Single Email Verification

Verifies an individual email address by executing syntax parsing, DNS MX record lookup, and an SMTP handshake probe.

Request Body

{
  "email": "user@example.com"
}

Response Format

The API returns a JSON object containing detailed result indicators and overall classification:

{
  "email": "user@example.com",
  "status": "valid",
  "syntax_valid": true,
  "mx_found": true,
  "smtp_valid": true,
  "is_disposable": false,
  "is_role_account": false,
  "is_catch_all": false,
  "domain": "example.com",
  "reason": "SMTP mailbox exists and accepts emails."
}

Code Integration Examples

curl -X POST https://listemailcheck.com/verify-single \
  -H "Content-Type: application/json" \
  -d '{"email": "test@example.com"}'

import requests

url = "https://listemailcheck.com/verify-single"
payload = {"email": "alex@company.com"}
headers = {"Content-Type": "application/json"}

response = requests.post(url, json=payload, headers=headers)
result = response.json()

if result.get("status") == "valid":
    print("Email is valid!")
else:
    print(f"Verification status: {result.get('status')} - {result.get('reason')}")

async function verifyEmail(email) {
  const response = await fetch("https://listemailcheck.com/verify-single", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ email: email })
  });

  const data = await response.json();
  console.log("Status:", data.status, "Details:", data);
  return data.status === "valid";
}

verifyEmail("user@example.com");

<?php
$ch = curl_init('https://listemailcheck.com/verify-single');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ['Content-Type: application/json']);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode(['email' => 'user@example.com']));

$response = curl_exec($ch);
curl_close($ch);

$result = json_decode($response, true);
echo "Status: " . $result['status'];
?>

HTTP Status Codes

Rate Limits & Quotas

Unauthenticated guest requests are limited to 5 verifications per 24 hours. Registered users receive 1,000 free verifications per day. Higher quotas are available on paid tiers: