Odel
deliverability doctor

deliverability doctor

@integrity-osJavaScriptMITUpdated 1w ago

Check if a domain can be email-spoofed: SPF, DMARC, DKIM, MX graded from public DNS. Authless.

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Server endpointStreamable HTTPNo authProbed
https://deliverability-doctor.deliverability-doctor.workers.dev/mcp

This is the third-party server itself — Odel doesn't run it. Hitting this URL directly talks straight to the upstream server with no auth or proxying. Connect through Odel to front it with managed auth.

Deliverability Doctor

Remote MCP server: "Can my domain be email-spoofed?" answered from public DNS, graded, with concrete fixes. Connectable to Claude (custom connector) and ChatGPT (Apps SDK / MCP connector) — both speak MCP, one server serves both.

Tools

  • check_email_security(domain) — SPF (incl. RFC 7208 multiple-record permerror and redirect= handling), DMARC (policy, rua, pct), MX, DKIM at 7 common selectors. Graded A–F report, fixes per finding, upsell line only when problems exist. Accepts bare domain, URL, or email address.
  • compare_email_security(domains[2..5]) — comparison table with grades.

Design decisions

  • Authless: reads public DNS only, stores nothing, takes nothing but a domain. Lowest possible connect friction; nothing sensitive to protect.
  • DNS-over-HTTPS (Cloudflare → Google fallback): identical code runs on local Node and on Cloudflare Workers — no dns module dependency.
  • Stateless streamable HTTP: fresh transport per request, no sessions; safe to scale, trivial for clients.
  • NXDOMAIN is refused, not graded — "domain doesn't exist" ≠ "spoofable".
  • Verified against known postures before first run: gmail.com (redirect= must not be flagged), n8n.io (must grade A on p=reject), missing-everything domain (must grade F), NXDOMAIN (must refuse).

Run

npm install
node server.js          # :8787/mcp

Quick public demo: cloudflared tunnel --url http://localhost:8787 → use https://<random>.trycloudflare.com/mcp as the connector URL.

Status 2026-08-23

  • Local: end-to-end MCP verified (initialize / tools/list / tools/call).
  • Public: live via quick tunnel, initialize verified from the public URL.
  • Durable hosting: pending — Cloudflare Workers deploy needs Kacper's account (~5 min). Tunnel URL dies with the process/PC.
  • Directory submissions (Anthropic connector directory, ChatGPT apps): need the durable URL first, then Kacper's developer accounts.

Monetization path

Free tool = distribution. Report links the $99 written audit (niekonieczny.gumroad.com/l/vscjt) only when problems are found. NOTE: Gumroad payouts currently frozen on Stripe KYC — unfreeze before promoting.