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Domain Intel — MX Fastmail Lookup
x402
Domain Intel — MX Fastmail Lookup is a paid API for AI agents from dns.halowerk.com, paid per call via x402, $0.009/call, status unknown (last checked 2026-10-13).
Checks whether a domain's MX records point to Fastmail, optionally comparing against a baseline snapshot, and returns full domain intelligence including WHOIS, DNS, mail policy, TLS certificate, and subdomains.
Price / call$0.009
Success—
StatusUnknown
How this service works
Requires an unauthenticated caller-owned baseline; returns real current NS/MX records, added/removed sets and tri-state target-provider transition. Current DNS comes from one bounded native recursive-resolver query; existing Dossier provides context. Resolver caching may apply; no account ownership or global migration-completion claim. Existing provider patterns are reused without new invented attribution. At most50records,domain253chars,9sbudget; DNSsubquery2s/oneattempt. Unknown provider remai
Output
Returns a comprehensive domain intelligence report covering WHOIS registration data, full DNS record set, MX records with Fastmail match status, SPF/DKIM/DMARC mail policy, TLS certificate details, and discovered subdomains. If a baseline is provided, includes a comparison indicating whether MX records have changed since the observed timestamp.
Example use cases
Verify vendor email runs on Fastmail
“I need to confirm that vendor-corp.io actually routes email through Fastmail — can you look up its MX records and tell me if they match Fastmail's servers? Also grab the WHOIS and any subdomains while you're at it.”
Detect email provider switch to Fastmail
“We recorded these MX records for startupxyz.com back on 2024-03-01 — mx1.messagingengine.com at priority 10 and mx2.messagingengine.com at priority 20. Can you re-check now and tell me if anything has changed?”
Security audit of domain mail infrastructure
“Run a full domain intel check on newsletter-sender.com — I want WHOIS ownership details, current DNS records, whether they're on Fastmail, their TLS certificate, mail policy, and any subdomains you can find.”
Technical details
Endpoint
POSThttps://dns.halowerk.com/domain/articles/mx-fastmail?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you specifically need to verify or monitor Fastmail MX record presence for a domain alongside comprehensive domain intelligence (WHOIS, DNS, TLS, subdomains) in a single pay-per-call request with no signup. Prefer it over generic WHOIS or DNS APIs when Fastmail-specific mail routing verification is the primary goal, or when you need to diff current MX state against a stored baseline. It is ideal for lightweight, one-off agent tasks where recurring API keys are impractical and micropayment via USDC is acceptable.
Side effects
- Invalid or non-existent domain returns an error or empty result set
- Domain with no MX records returns null mail policy data
- Baseline schema mismatch (missing required fields: domain, observed_at, records) causes validation error
- Payment failure over x402 prevents the call from completing
- DNS resolution timeout for slow or obscure TLDs may produce partial results
- MX priority values outside 0–65535 or exchange hostnames over 254 characters are rejected
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| domain | string | |
| baseline | object |
Tags
x402
Reviews
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