Email Validation API Guide for Developers

An email validation API lets applications verify addresses at registration, checkout, or CRM import—without building DNS and disposable logic yourself.

What the API does

Typical responses include overall validity, a numeric score, and flags for syntax, MX, disposable, and role-based addresses. Clients POST an email JSON payload and receive structured results suitable for UI badges or automated rejection rules.

Email Check Tool API

Base URL: https://emailchecktool.com/api. Endpoint: POST /api/verify with body {"email":"user@example.com"}. See full reference on our API documentation page and pricing for rate limits.

Example: curl

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

Example: JavaScript

const res = await fetch('/api/verify', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({ email: value })
});
const data = await res.json();

Example: PHP

$response = Http::post('https://emailchecktool.com/api/verify', [
  'email' => $request->input('email'),
]);

Error handling

Handle 400 for missing email, 422 for validation errors, 429 when rate limited, and 500 for server faults. Back off exponentially on 429 and cache recent results per address to reduce calls.

Best practices

Validate on blur for UX, re-check before payment capture, log scores not raw emails where privacy requires minimization, and combine API results with double opt-in for marketing lists.