Skip to content
ToolCargo

DNS & email auth

Live

SPF, DMARC, MX and DKIM lookups before a client domain goes live.

Ask whether a domain can receive mail and whether SPF and DMARC are set. Uses public resolvers; it does not send mail or change DNS.

Server URL

streamable http
https://toolcargo.com/mcp/dns-email

Claude Code

terminal
claude mcp add --transport http --scope user toolcargo-dns-email https://toolcargo.com/mcp/dns-email \
  --header "Authorization: Bearer YOUR_API_KEY"

Create a key in your dashboard. Other clients: setup guides.

What it helps you do

  • See MX and whether mail can be received
  • Read SPF and DMARC policy
  • Check a DKIM selector if you know it

Built for: Agencies launching or migrating client domains.

Example requests

Pre-launch mail

“Inspect DNS and email auth for client.com with ToolCargo, DKIM selector google.”

MX, SPF terminal policy, DMARC p=, and the google._domainkey TXT if present.

Step-by-step workflows: pre-launch check · fixing link previews

Tools

ToolWhat it doesAccess
inspect_dns_email
Inspect DNS and email authentication
MX, A/AAAA, NS, SPF and DMARC for a public domain, plus an optional DKIM selector lookup. Public resolvers only.Read-only

Requirements

  • • A ToolCargo account with Site Audit activated (free).
  • • The domain must be publicly delegated.

Limitations

  • • Does not send probe mail. Private/local hostnames are refused. DKIM needs the selector name.

Supported clients

“Tested” means we connected that client to this endpoint and ran a tool call ourselves. “Documented” means the client supports this setup per its own docs, but we have not tested it yet.

Claude CodeAPI key headerTestedRemote HTTP server with an Authorization header. Tested 2026-09-11 (v2.1.268).
Claude (claude.ai)OAuth sign-inTestedCustom connector with OAuth sign-in; tested on claude.ai web 2026-09-11. Desktop and mobile use the same account connectors but were not tested separately.
CursorAPI key headerDocumented, not yet testedmcp.json with url and headers.
VS Code (Copilot agent mode)API key headerDocumented, not yet tested.vscode/mcp.json with type http and headers.
ChatGPT (developer mode)OAuth sign-inDocumented, not yet testedRequires OAuth; API keys cannot be entered.
MCP InspectorAPI key headerTestedCLI mode, tested 2026-09-11. Useful for calling tools directly.

Pricing

Free

$0

For trying the connector on your own sites.

50 calls/month · 25 links per check

Pro

$12/mo

For freelancers and agencies auditing client sites every week.

2,000 calls/month · 100 links per check

Proposed test price. See the pricing page for checkout status.

Full pricing and billing details