MailGuard
Email verification API for developers: the same syntax, MX, disposable & typo checks the big providers charge for, up to 100× cheaper than the next cheapest competitors on the market, with a free tier and a 2-minute setup.
Stop bad emails at signup with one fast call.
Get a free API key
500 verifications/month, free forever. No card required.
Your API key:
Or try the free email checker (no signup). Already a customer? Check usage and rotate your key on the account dashboard.
Quick start
curl https://mailguard-api.atek.workers.dev/v1/verify \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"email":"jane@gmial.com"}'
Response:
{
"email": "jane@gmial.com",
"status": "risky",
"score": 75,
"checks": { "syntax": true, "mx_found": true, "disposable": false, "role": false, "free_provider": false },
"did_you_mean": "gmail.com",
"reasons": ["Possible typo. Did you mean \"jane@gmail.com\"?"]
}
JavaScript / TypeScript SDK
Prefer a typed client? Install the official SDK from npm:
npm install mailguard
import { MailGuard } from "mailguard";
const mg = new MailGuard("YOUR_API_KEY");
const result = await mg.verify("jane@gmial.com");
// { status: "risky", score: 75, did_you_mean: "gmail.com", ... }
Zero dependencies. Works in Node, Bun, Deno, Cloudflare Workers, and the browser. View on npm · Source on GitHub.
Pricing
Roughly £0.00005–0.0001 per check: up to 100× cheaper than the usual £0.004–0.01.
The free tier is live now. Paid plans are coming soon; email us to register interest.
Endpoints
| Method | Path | Description |
|---|---|---|
| POST | /v1/verify | Verify one email |
| GET | /v1/verify?email= | Verify one email (querystring) |
| POST | /v1/verify/batch | Verify up to 100 at once |
| POST | /v1/verify/csv | Bulk-verify a CSV / list |
| GET | /v1/health | Health check (no key) |
Authenticate with Authorization: Bearer <key> or x-api-key: <key>.
FAQ
Is there a free email verification API tier?
Yes. You get 500 verifications a month, free, with no card required.
What does MailGuard check?
Email syntax, the domain's MX (mail server) records, disposable and role-account detection, a 'did you mean?' typo suggestion, and a 0–100 deliverability score.
Does it do SMTP mailbox verification?
No. It is a fast syntax, MX, and heuristic verifier. That keeps it cheap and is the right level for stopping bad emails at signup.
Is it GDPR compliant?
Yes. We do not store the email addresses you verify; we cache only the domain's mail-server result. See our privacy policy for detail.
How much does it cost?
Free for 500 checks a month. Paid plans start at £5/month.
Which languages and frameworks does it work with?
Any. It is a REST API, with an official npm SDK for JavaScript and TypeScript.
From the blog
Why MailGuard: A Cheaper Email Verification API for Developers
MailGuard is an email verification API built for developers: syntax, MX, disposable and typo checks in one call, up to 100× cheaper than the incumbents, with a real free tier.
Email Verification API Pricing: What You Should Pay
Most email verification APIs charge a fraction of a cent to a penny per check, which adds up fast. Here's how pricing works and how MailGuard compares.
Add Email Verification to Your Signup Form in Minutes
A quick guide to adding email verification to any signup form with MailGuard: catch typos, fakes, and disposable addresses with one API call or the npm SDK.