PUBLIC DNS ONLY · AGENT-FRIENDLY · BUYER-CONTROLLED X402

Before you email a domain,
check its DNS.

A missing mail exchanger or a misconfigured policy can be worth flagging before an agent tries to contact a company. Review public MX, SPF and DMARC configuration on demand. This is an inexpensive configuration hint, not a promise that any email will arrive.

Run FREE REAL public MX/SPF/DMARC preview ↓ View free invented JSON sample ↗ See optional paid API →

A real free DNS overview is now available at the linked separate buyer page: it contacts independent Google Public DNS only after an explicit click, sending the visitor-selected public domain and normal browser metadata to Google, not to VM5. It checks configuration only, NOT mail arrival, individual mailbox existence, Google Group posting rights or DKIM. It makes no wallet or USDC call. No signup or wallet for the invented sample. No email address or message body is collected on this page. Never send account credentials, mailbox tokens, password-reset links, or DKIM private keys.

USEFUL SIGNALS, NOT CLAIMS OF DELIVERY

Three public DNS questions an operator can review

MX — Where could mail go?

List advertised mail exchangers. A listed MX does not establish that a mailbox exists or that mail will be accepted. No MX record alone is not universal proof of failure; SMTP has specific fallback behavior.

SPF — Is an authorization policy published?

Identify the existence of a v=spf1 TXT policy. A string existing is not enough to prove correct syntax or alignment. Multiple SPF policies and too many DNS lookups merit a separate standards-aware review.

DMARC — What policy is requested?

Inspect published _dmarc policy values such as p=none, quarantine or reject. A requested DNS policy is not evidence that a specific sent message passes SPF/DKIM alignment.

START WITHOUT SPENDING

Free fixture: see the response shape

Our public free JSON sample is fictional. It shows the machine-readable fields without querying any real domain or charging a wallet. The values below are illustrative and not DNS observations about example.org.

Read the entire public sample ↗

{
  "kind": "public_email_dns_preflight",
  "domain": "example.org",
  "mxCount": 1,
  "spfPresent": true,
  "dmarcPresent": true,
  "dmarcPolicy": "reject",
  "inspectedAtUTC": "FIXTURE_ONLY_NOT_LIVE_DNS"
}

MACHINE-READABLE, OPTIONAL PURCHASE

Agent buyers can request a real quote first

First try the live FREE public DNS summary (zero USDC) linked in the buyer button below to see the actual domain MX/SPF/DMARC configuration before deciding whether a structured API report adds value. Free mode sends the selected public domain to Google Public DNS, not the merchant; no mailbox or deliverability guarantee. The paid operation is separately buyer-selected.

The original VM5 merchant hosts GET /v1/email-dns-preflight. An ordinary unsigned HTTP request responds with an x402 payment requirement: 0.005 native Circle Base USDC (5,000 six-decimal token units). An HTTP 402 is a quote, not proof of a customer payment, not a 200 report, and not permission to send funds.

Preview the quote without approving any wallet payment:

curl -i --max-time 35 \
  'https://vm5-openapi-x402.onrender.com/v1/email-dns-preflight?domain=example.com'

Read the free machine-readable OpenAPI specification ↗ before integration. A buyer must independently check the live network, exact canonical USDC contract, amount, payee, URL, x402 authorization and settlement/response handling before signing. The service does not require giving us a buyer's private key or seed phrase. If settlement or a response is uncertain, do not blindly resend a paid request without checking whether the charge already went through.

Open buyer-initiated 0.005-USDC checkout ↗ Inspect unsigned 402 API quote ↗ Request a nonconfidential integration discussion ↗

The separate static checkout link above now offers a buyer-controlled wallet opt-in for the same existing merchant. Its happy payment path is tested with FAKE browser wallets only, not an independently paid live human sale. Opening the bare 402 URL in a normal browser may show a technical error or payment challenge; it is not a working human checkout. Payment requires a compatible x402 client and explicit buyer action. No buyer payment, repeat purchase, or recurring revenue is implied by this page.

WHAT WE WILL NOT PRETEND

Published DNS is not inbox deliverability

Not checked

Mailbox existence, SMTP handshake, DKIM selector validation, SPF/DKIM pass for a particular message, actual spam-folder placement, user consent, or whether a person will reply.

Operational caveats

DNS may be cached, change after inspection, or use split-horizon/private resolvers. This is a bounded public-data preflight, not a continuous monitor or security/compliance certification.

Privacy and consent

Only pass a public domain you may inspect. The sample page runs as static HTML with no JavaScript, tracking or input collection. An independently chosen paid request sends the public domain to the API for DNS lookup; don't send personal emails or private account details.

This project is openly AI-assisted and owned by one human economic beneficiary across VM development environments. The existing original API can answer public DNS questions, but zero independently confirmed buyers have purchased this specific DNS product as of publication. No paid transaction is simulated here.