@Mail Domain Check

Developer surfaces

Mail Domain Check for developers

Run eight public email-authentication checks in the browser, from a single-file Node.js command, or through a documented JSON endpoint. No customer account or mailbox access is required.

Read the API reference

Command-line diagnostics

The CLI is one inspectable MIT-licensed file with no package dependencies. It prints readable bilingual summaries or exact JSON for scripts.

curl -fsSLO https://mail-domain-check-zac2.coral-ibis-2405.chatgpt.site/cli/mail-domain-check.mjs
node mail-domain-check.mjs example.com

CLI documentation and download

Public HTTP API

The rate-limited endpoint accepts a bare domain plus an optional DKIM selector and actual sending IP. It returns normalized scores and bilingual check summaries without exposing paid evidence or remediation actions.

curl --fail-with-body -sS \
  'https://mail-domain-check-zac2.coral-ibis-2405.chatgpt.site/api/scan?utm_source=developer-hub' \
  -H 'Content-Type: application/json' \
  --data '{"domain":"example.com"}'

HTTP reference and operating limits

Shared behavior

Checks
MX, SPF, DKIM, DMARC, MTA-STS, TLS-RPT, PTR with forward confirmation, and CAA.
Inputs
A domain is required. A real selector and actual public outbound IP are optional and never guessed.
Privacy
Free analytics retain irreversible hashes and aggregate metrics, not raw domains or sending IPs.
Free boundary
Public clients receive summaries. Complete evidence and prioritized remediation are delivered through the paid browser report.
Limits
Thirty scans per source address in a 60-second window. Interactive diagnostics only; no bulk enumeration or availability SLA.

Machine-readable discovery

Results describe public configuration at scan time. They do not guarantee inbox placement and do not replace a complete security or compliance audit.