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Lookproof MX Record Lookup
x402
Lookproof MX Record Lookup is a paid API for AI agents from api.lookproof.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-31).
Lists a domain's mail servers in priority order and detects null MX (RFC 7505) or unresolvable MX targets, with coded diagnostic findings.
Price / call$0.01
Success—
StatusUnknown
How this service works
Check SPF, DMARC, DKIM, MTA-STS, DNSSEC and more, with results that explain what was found and why. Free browser checks and a pay-per-request API with x402.
Output
Returns an ordered list of MX records for the domain (hostname and preference value for each), a flag indicating whether a null MX (RFC 7505) is present, the resolution status of each MX target hostname, and coded findings describing any detected issues such as unresolvable targets or missing MX records.
Example use cases
Email deliverability pre-flight check
“Before we send the campaign, check that newsletter.example.com actually has working mail servers — list the MX records in order and flag any that don't resolve.”
Detect domain that blocks inbound mail
“Does parked-domain.io have a null MX record set? I want to know if it's deliberately configured to reject all incoming email under RFC 7505.”
Identify mail provider for a prospect domain
“Can you find where email for bigcorp.com is delivered? I need to know which mail servers handle their inbound mail and in what priority order.”
Technical details
Endpoint
GEThttps://api.lookproof.dev/v1/mail/mx?utm_source=zero.xyzWhen to prefer
Use this endpoint when you specifically need to understand mail routing for a domain — either to enumerate MX servers in priority order, detect a null MX (RFC 7505) indicating the domain intentionally rejects mail, or diagnose why a domain cannot receive email. Prefer this over a generic DNS resolver endpoint when you need structured mail-routing semantics, coded diagnostic findings, and RFC 7505 null MX detection rather than raw DNS record data.
Side effects
- Domain does not exist (NXDOMAIN) — returns no MX records with a not-found diagnostic code
- Domain has no MX records — returns empty list with a coded finding indicating no mail routing configured
- MX targets exist but do not resolve to any IP — flagged per-target with a resolution-failure code
- Malformed or excessively long domain input — rejected with a validation error
- DNS resolver timeout — may return partial results or a timeout error code
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object |
Tags
x402
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