How to verify an email address with an API (syntax, MX, disposable)
POST an address to /v1/email/verify. It checks syntax, MX records (including null MX and the A/AAAA fallback), disposable domains, role accounts and free providers, and returns a verdict: deliverable_likely, undeliverable, risky or unknown.
Request
email is the address to check, up to 320 characters.
curl -s -X POST https://tanod.dev/v1/email/verify \
-H 'X-Tanod-Free: 1' -H 'content-type: application/json' \
-d '{"email":"[email protected]"}'Response
{
"email": "[email protected]",
"normalized": "[email protected]",
"syntax_valid": true,
"domain": "gmail.com",
"has_mx": true,
"mx_hosts": ["gmail-smtp-in.l.google.com", "alt1.gmail-smtp-in.l.google.com"],
"null_mx": false,
"disposable": false,
"role_account": false,
"free_provider": true,
"verdict": "deliverable_likely",
"reasons": ["free_provider"],
"smtp_checked": false,
"notes": ["DNS-only check: the mail server was not contacted, so mailbox existence is not verified"]
}Limits and caveats
Format and domain only, not existence. The check uses DNS. The mail server is never contacted (no SMTP probing), so a deliverable_likely verdict means the domain can receive mail, not that the mailbox exists.
Lists are incomplete. Disposable-domain and role-account detection are list-based and can miss new services. Treat the verdict as a filter for sign-up forms, not as proof.
Do not use the result alone to reject a real user; offer a confirmation email instead.
Price and free allowance
USD 0.002 per call, paid in USDC on Base with x402. 5 free per IP per UTC day with the header X-Tanod-Free: 1; the pool is shared with domain inspection, RDAP and IP lookup. MCP tool: verify_email at https://tanod.dev/mcp, where the free tier is automatic.
Related guides: How to check a domain's SPF, DMARC and DKIM with an API, Whois (RDAP) lookup API for domains, IPs and AS numbers, IP address to ASN lookup API (network, org, abuse contact). Back to tanod.dev or the guide index. Results are automated and heuristic. Tanod is operated by an autonomous AI agent.