API Reference

Email Validation API

Validate email addresses in real time to catch disposable, invalid, and high-risk sign-ups before they reach your product.

Base URL

All API requests should be made to the following base URL.

https

https://api.trueguard.io/v2

Authentication

All API requests require authentication using your secret API key.

Security note

Never expose your secret API key in client-side code. Only use it in your backend services.

Required Header

header

x-api-key: YOUR_SECRET_API_KEY

How it works

Each validation request runs a multi-step pipeline to assess the email address.

Syntax validation checks that the address is structurally well-formed.
Domain checks resolve MX records, A records, domain age, and high-risk TLD classification.
Quality checks identify disposable providers, free email services, role accounts, and plus-addressing.
SMTP deliverability check connects to the mail server to determine whether the address is reachable, catch-all, full, or disabled. This step only runs when syntax is valid and the domain has MX records.
Status is assigned: a result starts as "safe" and is downgraded to "risky" if the address is disposable, catch-all, or uses a high-risk TLD.

Endpoints

Validate a single email address and receive a full breakdown of syntax, deliverability, domain, and quality signals.

POST/email/validation

Email Validation

Validate a single email address. Returns syntax, deliverability, domain, and quality signals so you can block disposable, invalid, and high-risk sign-ups.

javascript

import axios from 'axios';

const response = await axios.post(
  "https://api.trueguard.io/v2/email/validation",
  {
    email: "user@example.com",
  },
  {
    headers: {
      "x-api-key": "YOUR_SECRET_API_KEY",
    },
  }
);

bash

curl -X POST https://api.trueguard.io/v2/email/validation \
  -H "x-api-key: YOUR_SECRET_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"email":"user@example.com"}'

Error handling

Understanding and handling API error responses.

HTTP Status Codes

400Bad Request - Missing or invalid email, or malformed request body

401Unauthorized - Invalid or missing API key

403Forbidden - Your plan does not include the Email Validation API

429Too Many Requests - Quota exceeded for the current billing period

500Internal Server Error - Something went wrong on our end

Usage is metered per billing period. Check your dashboard for current plan limits and remaining quota.

Support

Need help with integration?

Check out our quick start guide or reach out to our support team for assistance with implementing the Email Validation API.

Quick Start Guide Contact Support