Domain Health MCP

This MCP server performs comprehensive domain health checks, analyzing email authentication protocols (SPF, DKIM, DMARC, BIMI, MTA-STS), SSL/TLS certificate validity, security headers, and domain registration status. It provides actionable fixes and severity ratings to ensure email deliverability and website security.

Endpoint and access

No sign-in: your client connects and lists tools immediately, with no account or key.

No sign-inEndpoint checked 2026-10-18Operated by Modern Mustard Seed

MCP endpoint (Streamable HTTP)

https://mcp.modernmustardseed.com/domain-health

Vendor documentation

What you can do with it

Check SPF, DKIM, and DMARC records to ensure email deliverability
Verify SSL certificate validity and TLS configuration
Analyze security headers like HSTS and CSP
Check domain registration status and DNSSEC

Tools advertised by the last live check:

check_email_auth
check_ssl
check_security_headers
check_domain_registration
full_domain_report

Connect from your client

Each snippet registers the same endpoint; pick the client you use.

This server is operated by the named third party. Listing and endpoint checks are not an endorsement or a security audit. Review the operator's permissions, terms, and data handling before connecting. How listings are checked and corrected.

Claude Code

Run this once in a terminal. It registers a Streamable HTTP server. Use --scope project to write .mcp.json for the repo.

Claude Code configuration

claude mcp add --transport http domain-health-mcp https://mcp.modernmustardseed.com/domain-health

Codex

Run this once. Codex stores MCP servers in ~/.codex/config.toml (or .codex/config.toml in a trusted project).

Codex configuration

codex mcp add domain-health-mcp --url https://mcp.modernmustardseed.com/domain-health

Cursor

Merge this server into .cursor/mcp.json in your project, then enable domain-health-mcp in your MCP settings.

Cursor configuration

{
  "mcpServers": {
    "domain-health-mcp": {
      "url": "https://mcp.modernmustardseed.com/domain-health"
    }
  }
}

Cline

Merge this into cline_mcp_settings.json (Cline → MCP Servers → Configure). The type must be streamableHttp for a remote HTTP server.

Cline configuration

{
  "mcpServers": {
    "domain-health-mcp": {
      "type": "streamableHttp",
      "url": "https://mcp.modernmustardseed.com/domain-health",
      "disabled": false
    }
  }
}

VS Code

Merge this server into .vscode/mcp.json. Use MCP: List Servers to start domain-health-mcp and inspect its tools.

VS Code configuration

{
  "servers": {
    "domain-health-mcp": {
      "type": "http",
      "url": "https://mcp.modernmustardseed.com/domain-health"
    }
  }
}

Gemini CLI

Run this once. It writes .gemini/settings.json in the current project; pass --scope user for ~/.gemini/settings.json.

Gemini CLI configuration

gemini mcp add --transport http domain-health-mcp https://mcp.modernmustardseed.com/domain-health

Claude Desktop

Merge this into claude_desktop_config.json (macOS: ~/Library/Application Support/Claude/, Windows: %APPDATA%\Claude\), then restart Claude Desktop.

Claude Desktop configuration

{
  "mcpServers": {
    "domain-health-mcp": {
      "url": "https://mcp.modernmustardseed.com/domain-health"
    }
  }
}

Windsurf

Merge this into ~/.codeium/windsurf/mcp_config.json, then refresh MCP in Cascade. Windsurf remote servers use serverUrl, not url.

Windsurf configuration

{
  "mcpServers": {
    "domain-health-mcp": {
      "serverUrl": "https://mcp.modernmustardseed.com/domain-health"
    }
  }
}

See all 1,222

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