How do I install Deliverability Doctor?

Copy the http config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does Deliverability Doctor need an API key?

No required environment variable is listed on this record.

What transport does Deliverability Doctor use?

Deliverability Doctor is reached over HTTP.

When was Deliverability Doctor last checked?

Last checked 2026-11-09. Check if a domain can be email-spoofed: SPF, DMARC, DKIM, MX graded from public DNS. Authless.

Deliverability Doctor MCP server

Power your agent

Add this server

The publisher's own URL. Not a PlugMCP endpoint.

Add to Cursor Add in Claude Add to VS Code Run on PlugMCP

Host a copy with our keys and logs.

Server URL

https://deliverability-doctor.deliverability-doctor.workers.dev/mcp

The Claude button above opens Claude with the name and URL filled in. You still confirm it there.

shClaude Code

1claude mcp add --transport http io.github.integrity-os-deliverability-doctor https://deliverability-doctor.deliverability-doctor.workers.dev/mcp

Run in a terminal.

jsonClaude Desktop

1{2  "mcpServers": {3    "io.github.integrity-os-deliverability-doctor": {4      "command": "npx",5      "args": [6        "-y",7        "mcp-remote",8        "https://deliverability-doctor.deliverability-doctor.workers.dev/mcp"9      ]10    }11  }12}

claude_desktop_config.json

Remote · HTTPPublisher installStep-by-step: add this in Claude

Remote URL or a command on your machine? How the two installs differ

Run on PlugMCP

Host a copy with our keys and logs.

A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.

Launch

Server facts

Remote

Transport: http
Version: 1.0.2
Last checked

Tools

No tool list yet. Remote servers get one after the first health check.

FAQ

Questions

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.

Add this server

Host a copy with our keys and logs.

Server facts

Tools

Questions

How do I install Deliverability Doctor?

Does Deliverability Doctor need an API key?

What transport does Deliverability Doctor use?

When was Deliverability Doctor last checked?

Documentation