# DMARC Shark — Email DNS Checker

> Check a domain's public SPF, DMARC, MX and DKIM DNS records on demand. No account required.

- name: com.dmarcshark/email-dns-checker
- version: 1.0.0
- connection class: R0 (autonomous)
- trust: 96/100
- quality: 94/100 (new)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/com.dmarcshark%2Femail-dns-checker
- tools: https://api.protogrid.dev/v1/servers/com.dmarcshark%2Femail-dns-checker/tools

**An agent can connect right now, no human step.** Remote endpoint, no authentication, reachable on the last probe.

## Connection (mcpServers)

```json
{
  "mcpServers": {
    "email-dns-checker": {
      "type": "http",
      "url": "https://dmarcshark.com/mcp"
    }
  }
}
```


## Trust

- hygiene: 100
- liveness: 100
- freshness: 100
- provenance: 85
- drivers: +repository +dns-namespace +website +reachable +uptime-100% +updated-2d-ago
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 94/100 (new)

### protocol: 88 (weight 25)

- pass `protocol.modern`: supports 2026-07-28 (server/discover)
- pass `protocol.stateless`: answers without a session
- pass `protocol.transport`: streamable HTTP
- warn `protocol.list_ttl`: tools/list declares ttlMs 0, so clients re-fetch it on every use

### authorization: n/a (weight 15)

- n/a `auth.prm`, `auth.as_metadata`, `auth.cimd`: no remote uses OAuth
- n/a `auth.secret_in_url`: no templated URL

### tool hygiene: 100 (weight 30)

- pass `tools.descriptions`: every tool has a description
- pass `tools.description_length`: descriptions are concise
- pass `tools.schemas`: every tool has an object input schema
- pass `tools.annotations`: 2 of 2 tools declare readOnlyHint or destructiveHint
- pass `tools.directory_hints`: every tool declares readOnlyHint, destructiveHint, idempotentHint and openWorldHint
- pass `tools.token_cost`: about 214 tokens to load every tool
- pass `tools.api_dump`: tools are not a one-to-one API dump

### stability: n/a (weight 15)

- n/a `stability.changes`, `stability.rug_pull`: tool history recorded for 1 of the 7 days needed

### dependencies: n/a (weight 15)

- n/a `deps.known_vulns`, `deps.mcp_sdk_version`, `deps.resolvable`: no npm or PyPI package

- tools: 2, about 214 tokens to load them all
- tool set hash: 9dd945752e4a486efb6c6589d188a184
- badge: [![protogrid quality](https://protogrid.dev/badge/com.dmarcshark/email-dns-checker.svg)](https://protogrid.dev/servers/com.dmarcshark/email-dns-checker)
- Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed.

### Tool changes

_No tool definition changes recorded._

## Remotes

- https://dmarcshark.com/mcp (streamable-http, auth none, reachable true, uptime30d 1)

## Packages

_none_

## Tools (2)

- `check_domain`: Runs fresh, bounded public SPF, DMARC, MX and optionally specified DKIM-selector DNS checks. Changes the public saved snapshot. Rate limited. DNS findings do not prove message authentication.
- `get_saved_result`: Reads the last saved, timestamped public snapshot without making any DNS queries. Results expire after 90 days.