Email Verification API Docs

Quick Start

Verify a single email with any of these snippets:

cURL

curl -X POST https://kaijuverifier.com/api/validate-email \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{"email":"user@example.com","use_smtp":true}'

JavaScript (fetch)

const r = await fetch('https://kaijuverifier.com/api/validate-email', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'Authorization': 'Bearer YOUR_API_KEY'
  },
  body: JSON.stringify({ email: 'user@example.com', use_smtp: true })
});
const data = await r.json();
console.log(data.status, data.score, data.grade);

Python (requests)

import requests
r = requests.post(
    'https://kaijuverifier.com/api/validate-email',
    headers={'Authorization': 'Bearer YOUR_API_KEY'},
    json={'email': 'user@example.com', 'use_smtp': True}
)
print(r.json())

PHP (cURL)

$ch = curl_init('https://kaijuverifier.com/api/validate-email');
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'Content-Type: application/json',
        'Authorization: Bearer YOUR_API_KEY'
    ],
    CURLOPT_POSTFIELDS => json_encode(['email' => 'user@example.com', 'use_smtp' => true])
]);
$data = json_decode(curl_exec($ch), true);

Response fields

Status codes & rate limits

• 200 — Verification completed.
• 400 — Missing or malformed email field.
• 401 — Invalid or missing API key.
• 429 — Rate limit exceeded.

Rate limits: 20 req/min for anonymous IPs (50 SMTP probes/day). Authenticated keys inherit their plan quota (Free 10k/mo, Starter 100k/mo, Pro 1M/mo).

API Overview

The Kaiju Email Verification API allows developers to integrate our industry-leading email cleaning capabilities directly into their applications, CRMs, or registration forms. Verify emails in real-time to prevent fake signups or process bulk lists programmatically.

Authentication

All API requests require authentication using a Bearer Token. You can generate and manage your API keys in your dashboard settings.

Authorization Header

Authorization: Bearer YOUR_API_KEY_HERE

Base URL

All API endpoints are relative to the following base URL:

https://api.kaijuverifier.com/v1

API Endpoints

curl -X POST "https://api.kaijuverifier.com/api/v1/verify" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "email": "user@example.com",
    "use_smtp": true
  }'

{
  "emails": [
    "user1@example.com",
    "user2@example.com",
    "invalid@domain.com"
  ],
  "use_smtp": true
}

curl -X POST "https://api.kaijuverifier.com/api/v1/batch" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "emails": ["user1@example.com", "user2@example.com"],
    "use_smtp": true
  }'

<?php
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://api.kaijuverifier.com/api/v1/batch");
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode([
    "emails" => ["test@example.com"],
    "use_smtp" => true
]));
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    "Authorization: Bearer YOUR_KEY",
    "Content-Type: application/json"
]);
$response = curl_exec($ch);
curl_close($ch);
?>

import requests

response = requests.post(
    "https://api.kaijuverifier.com/api/v1/batch",
    headers={"Authorization": "Bearer YOUR_KEY"},
    json={
        "emails": ["test@example.com"],
        "use_smtp": True
    }
)
print(response.json())

Response Object

The API returns a JSON object with the verification results. Understanding these fields is key to handling the data correctly.

{
  "email": "user@example.com",
  "status": "valid",
  "score": 0.95,
  "details": {
    "is_disposable": false,
    "is_role_account": false,
    "has_mx_records": true,
    "smtp_connect": true
  }
}

Error Codes

Standard HTTP status codes are used to indicate success or failure.

Integration Best Practices

• Timeout Handling: Set a timeout of at least 5 seconds for single verification requests to account for DNS lookups.
• Asynchronous Processing: For bulk requests, consider using a background job queue to avoid blocking your main application thread.
• Caching: Cache verification results for 24-48 hours to save API credits and improve performance.