Email validation API: syntax, MX, disposable, free-provider, role-based, and typo checks in one call.
What it does
Mailcheck API at mailcheck.hugen.tokyo performs six email validation checks in a single request: syntax validation, MX record lookup, disposable email detection (covering 5,000+ domains), free provider identification, role-based address detection, and typo suggestion ("did you mean"). The API is designed for simplicity — no API keys or multiple service integrations are required.
The primary endpoint is POST /mailcheck/validate, which accepts an email address via JSON body, form data, or query parameter and returns a structured response including a validity status, a numeric score, detailed check results, and a list of checks performed. Additional utility endpoints include GET /mailcheck/disposable (check if a domain is disposable) and GET /mailcheck/mx (look up MX records for a domain). The API exposes a full OpenAPI 3.1 spec and an llms.txt endpoint for LLM agent discoverability.
Note: This endpoint is listed as an x402 pay-per-call service, but the probe returned HTTP 410 (Gone) on both POST and GET at the /validate path, rather than the expected 402 challenge. The x402 discovery document exists at /.well-known/x402, and the OpenAPI docs are live, but the paid endpoint itself may be decommissioned or relocated. Pricing information could not be determined from available material.
Capabilities
Use cases
- —Validate user-submitted email addresses at signup to reduce bounces
- —Detect disposable or throwaway email addresses to prevent abuse
- —Check MX records for a domain before sending transactional email
- —Suggest corrections for common email typos (e.g., gmial.com → gmail.com)
- —Filter out role-based addresses (info@, admin@) from marketing lists
Fit
Best for
- —Agents or apps needing quick, keyless email validation
- —Signup flows that need disposable-email blocking
- —Bulk email list hygiene pipelines
Not for
- —SMTP-level inbox verification (this API does not probe the mailbox)
- —High-volume production use without confirming the endpoint is live (currently returning 410)
Quick start
curl -X POST https://mailcheck.hugen.tokyo/mailcheck/validate \
-H "Content-Type: application/json" \
-d '{"email": "test@gmail.com"}'Example
Request
{
"email": "user@gmial.com"
}Response
{
"email": "user@gmial.com",
"score": 0.4,
"domain": "gmial.com",
"status": "risky",
"is_free": false,
"mx_found": false,
"mx_records": [],
"did_you_mean": "user@gmail.com",
"syntax_valid": true,
"is_disposable": false,
"is_role_based": false,
"checks_performed": [
"syntax",
"mx",
"disposable",
"free",
"role",
"typo"
]
}Endpoint
Quality
The OpenAPI spec is complete and well-structured, but the x402 endpoint returned HTTP 410 (Gone) on both POST and GET, indicating the paid endpoint may be decommissioned. No pricing information is available. The root URL returns 404. The service may not be operational for x402 payments.
Warnings
- —Endpoint returned HTTP 410 (Gone) on both POST and GET — the x402 paid endpoint may be decommissioned or moved
- —No pricing information found; x402 challenge was not returned so cost per call is unknown
- —Root URL (/) returns 404; only /docs and sub-endpoints appear functional
- —Response example is inferred from the OpenAPI schema, not from an actual successful call
Citations
- —6 email validation checks in one call — syntax, MX records, disposable detection (5,000+ domains), free provider, role-based, and typo suggestionhttps://mailcheck.hugen.tokyo/docs
- —Accept JSON body, form data, or query parameter for the validate endpointhttps://mailcheck.hugen.tokyo/docs
- —Endpoint returned HTTP 410 on both POST and GEThttps://mailcheck.hugen.tokyo/validate