Email Verification API — the email verifier API for developers
One REST endpoint. Verify any email in under 100ms. GDPR-compliant, EU-hosted, with SDKs for Node, Python, PHP, Ruby, and Go.
- What is an email verification API?
- An email verification API is an HTTP endpoint that tells you whether an email address is real and deliverable before you send to it. Mailbeam runs eight checks on every address — syntax, MX records, SMTP existence, disposable domains, role-based addresses, free providers, catch-all domains and a quality score — and returns a verdict, a score out of 100 and a machine-readable reason code your application can branch on.
What Mailbeam checks
Every verification runs 7 checks in parallel and returns a structured result in under 100ms.
Sub-100ms response time
Verify emails in real time at the point of signup without adding perceptible latency to your user flows.
Live SMTP verification
Connect directly to mail servers and confirm that a specific mailbox exists — not just that the domain has MX records.
EU-hosted, GDPR-first
All processing within EU infrastructure. No data retention after verification. DPA available for Article 28 compliance.
SDKs for every stack
Official libraries for Node.js, Python, PHP, Ruby, and Go. One function call returns a structured result.
Disposable & role detection
Block throwaway addresses and department inboxes (info@, admin@) with a continuously updated database.
Typo suggestion
When a user types 'gmal.com', return 'gmail.com' instantly so they can correct it before submitting.
How it works
Send a POST request
POST the email address to /v1/verify with your API key in the Authorization header. That's it.
DNS and MX lookup
Mailbeam queries DNS for the domain's MX records to confirm the domain can receive email.
SMTP handshake
We connect to the mail server and simulate a delivery attempt to confirm the specific mailbox exists — an email ping, in the informal term, that stops before anything is delivered.
Structured JSON result
Receive a JSON response with status (deliverable/risky/undeliverable/unknown), a 0-100 score, and individual check results.
Integrate in minutes
curl -X POST https://api.mailbeam.dev/v1/verify \
-H "Authorization: Bearer $MAILBEAM_KEY" \
-H "Content-Type: application/json" \
-d '{"email": "user@example.com"}'
# Response:
# {
# "email": "user@example.com",
# "status": "deliverable",
# "score": 97,
# "valid": true,
# "disposable": false,
# "role": false,
# "suggestion": null
# }When to use it
Signup forms
Validate at the point of registration to stop fake and mistyped emails before they enter your system.
API integrations
Programmatically verify emails from any backend language — one POST with a JSON body, so no client library is required.
Webhooks and async flows
Submit a list to the batch endpoint and let a signed batch.completed webhook tell you when it is ready, instead of polling.
CRM enrichment
Enrich contact records with verification status and score to power lead scoring and routing.
Frequently asked questions
How fast is the API?
Mailbeam responds in under 100ms at p99 for most domains. SMTP verification for unknown domains may take up to 500ms when the server is slow to respond.
What languages have official SDKs?
None yet — official libraries for Node.js, Python, PHP, Ruby and Go are on the roadmap, and the REST API ships first. It is a single POST with a JSON body, so a dozen lines of your HTTP client of choice covers it; the quickstart has a wrapper to copy for each language.
Is there a free tier?
Yes. The free tier includes 1,000 verifications per month with no credit card required. This is enough to integrate and test in production.
Does the API store email addresses?
Not for real-time verification — the address is discarded once the response is returned. Batch jobs are the one exception: the list and its results are kept for 72 hours so you can download them, then deleted automatically. Mailbeam is GDPR-compliant and EU-hosted.
What is the SLA?
A contractual SLA arrives with the paid plans. Live component status, checked on every page load, is at mailbeam.dev/status.
Ready to integrate?
Free tier includes 1,000 verifications/month. No credit card required.