English Français العربية

io.github.Integrity-Os/deliverability-doctor

Official registry Health

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

Source code Documentation

What can you do with io.github.Integrity-Os/deliverability-doctor?

  • check_email_security(domain) — SPF (incl. RFC 7208 multiple-record permerror
  • compare_email_security(domains[2..5]) — comparison table with grades.

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

Remote (streamable-http)
Claude Code 
claude mcp add --transport http deliverability-doctor 'https://deliverability-doctor.deliverability-doctor.workers.dev/mcp'
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "deliverability-doctor": {
            "type": "http",
            "url": "https://deliverability-doctor.deliverability-doctor.workers.dev/mcp"
        }
    }
}

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. Deliverability Doctor
  2. Tools
  3. Design decisions
  4. Run
  5. Status 2026-08-23
  6. Monetization path

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.

Frequently asked questions

What is io.github.Integrity-Os/deliverability-doctor?

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

How do I install io.github.Integrity-Os/deliverability-doctor?

It runs as a remote server. In Claude Code: claude mcp add --transport http deliverability-doctor 'https://deliverability-doctor.deliverability-doctor.workers.dev/mcp'. For other clients, paste the JSON configuration from this page into their MCP settings.

Does io.github.Integrity-Os/deliverability-doctor need an API key?

Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.

Is io.github.Integrity-Os/deliverability-doctor open source?

Yes. Its code is on GitHub under the MIT license.

Who maintains io.github.Integrity-Os/deliverability-doctor?

It is published by Integrity-Os. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.