# Email Auth Checker (remote · email-auth-check.quietworklabs.workers.dev)

SPF, DKIM, DMARC, MTA-STS and domain-expiry checks for any domain, with SPF lookup counts.

- Trust score: 74/100 (medium)
- Change this week: +3
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- remote · `email-auth-check.quietworklabs.workers.dev`: 74/100 (this document), [markdown](https://verifymcp.io/servers/dev-workers-quietworklabs-email-auth-check-email-auth-check/email-auth-check.md), [page](https://verifymcp.io/servers/dev-workers-quietworklabs-email-auth-check-email-auth-check/email-auth-check)

## Channel facts

- Endpoint: `https://email-auth-check.quietworklabs.workers.dev/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `1.0.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-11-05.

- **Endpoint Security**: 63/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - No authorisation is required to call this server. Nothing on it is marked destructive, but we can't show that an anonymous caller can only read: full credit needs the server to list at least one tool and every tool to be verifiably read-only. We use a best-effort check of tool names and descriptions to tell read-only tools from tools that change things, so some genuinely read-only tools may not get full credit. Names that start with a read verb (get, list, read, search and similar) and accurate readOnlyHint annotations help. Meet that to earn full credit, or require authorisation.
  - HTTPS enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 69/100
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 733 tokens (~183/item across 4 items; 4 tools + 0 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 60/100
  - Stability observed for 18 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 4 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 5 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

## Install

### How do I install the Email Auth Checker MCP server?

Email Auth Checker is a hosted endpoint at https://email-auth-check.quietworklabs.workers.dev/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http dev-workers-quietworklabs-email-auth-check-email 'https://email-auth-check.quietworklabs.workers.dev/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "dev-workers-quietworklabs-email-auth-check-email": {
      "url": "https://email-auth-check.quietworklabs.workers.dev/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "dev-workers-quietworklabs-email-auth-check-email": {
      "type": "http",
      "url": "https://email-auth-check.quietworklabs.workers.dev/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.dev-workers-quietworklabs-email-auth-check-email]
url = "https://email-auth-check.quietworklabs.workers.dev/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "dev-workers-quietworklabs-email-auth-check-email": {
      "type": "remote",
      "url": "https://email-auth-check.quietworklabs.workers.dev/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add dev-workers-quietworklabs-email-auth-check-email --url 'https://email-auth-check.quietworklabs.workers.dev/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  dev-workers-quietworklabs-email-auth-check-email:
    url: "https://email-auth-check.quietworklabs.workers.dev/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "dev-workers-quietworklabs-email-auth-check-email": {
      "Transport": "http",
      "Url": "https://email-auth-check.quietworklabs.workers.dev/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add dev-workers-quietworklabs-email-auth-check-email -t streamable-http -u 'https://email-auth-check.quietworklabs.workers.dev/mcp'
```

### Other

```json
{
  "mcpServers": {
    "dev-workers-quietworklabs-email-auth-check-email": {
      "type": "http",
      "url": "https://email-auth-check.quietworklabs.workers.dev/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-11-04 (score 74, +1)

No change was recorded against any check on this day. Stability & Change Management went from 53 to 57. That category is still filling its 30-day observation window: 16 days of observed history at the previous scan, 17 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-11-02 (score 73, +1)

No change was recorded against any check on this day. Stability & Change Management went from 47 to 50. That category is still filling its 30-day observation window: 14 days of observed history at the previous scan, 15 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-31 (score 72, +1)

No change was recorded against any check on this day. Stability & Change Management went from 40 to 43. That category is still filling its 30-day observation window: 12 days of observed history at the previous scan, 13 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-29 (score 71, +1)

No change was recorded against any check on this day. Stability & Change Management went from 33 to 37. That category is still filling its 30-day observation window: 10 days of observed history at the previous scan, 11 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-27 (score 70, +1)

No change was recorded against any check on this day. Stability & Change Management went from 27 to 30. That category is still filling its 30-day observation window: 8 days of observed history at the previous scan, 9 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-25 (score 69, +1)

No change was recorded against any check on this day. Stability & Change Management went from 20 to 23. That category is still filling its 30-day observation window: 6 days of observed history at the previous scan, 7 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-23 (score 68, +1)

No change was recorded against any check on this day. Stability & Change Management went from 13 to 17. That category is still filling its 30-day observation window: 4 days of observed history at the previous scan, 5 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-20 (score 67, +1)

No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.

## MCP tools (4)

### `email_auth_report` (~174 tokens)

Full email authentication report for a domain

Full email-auth report for a domain: SPF (recursive 10-lookup count, void lookups, +all/?all, terms after all), DMARC (policy, pct, alignment, rua authorization), DKIM (keys and RSA key bits at common selectors or your own via selectors=), MX/null MX, MTA-STS policy, TLS-RPT, BIMI, and a Gmail/Yahoo/Outlook bulk-sender readiness verdict. Deterministic DNS-over-HTTPS, no AI. Price: $0.003 USDC per call via x402 (Base); the first 5 calls per day per client are free.

Input parameters:

- `domain` (string, required): Domain (or email address) to check
- `selectors` (string): Optional comma list of DKIM selectors to probe (max 10)

### `spf_lookup_count` (~114 tokens)

SPF record tree with RFC 7208 lookup and void-lookup counts

Expands a domain's SPF record recursively (include/redirect) like a receiver does and counts DNS-querying terms against the RFC 7208 limit of 10 and void lookups against the limit of 2. Returns per-term lookup costs, problems (permerror causes) and warnings. Deterministic, no AI. Price: $0.001 USDC per call via x402 (Base); the first 5 calls per day per client are free.

Input parameters:

- `domain` (string, required): Domain to check

### `dmarc_check` (~104 tokens)

DMARC record parse and validation

Finds and validates a domain's DMARC record (falls back to the organizational domain): policy, subdomain policy, pct, alignment modes, rua/ruf, and whether external report domains authorized reports (RFC 7489 7.1). Deterministic, no AI. Price: $0.001 USDC per call via x402 (Base); the first 5 calls per day per client are free.

Input parameters:

- `domain` (string, required): Domain to check

### `domain_expiry` (~120 tokens)

Domain registration and expiry date via RDAP

Registration data for a domain from the registry's RDAP server (IANA bootstrap): registrar, created/updated/expiry dates, days until expiry with ok/expiring_soon/expired status, EPP status codes, nameservers and DNSSEC. Works for gTLDs and ccTLDs that publish RDAP. Deterministic, no AI. Price: $0.002 USDC per call via x402 (Base); the first 5 calls per day per client are free.

Input parameters:

- `domain` (string, required): Domain name

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/dev-workers-quietworklabs-email-auth-check-email-auth-check/email-auth-check#diagnostics

## Score history

- 2026-11-05: 74
- 2026-11-04: 74
- 2026-11-03: 73
- 2026-11-02: 73
- 2026-11-01: 72
- 2026-10-31: 72
- 2026-10-30: 71
- 2026-10-29: 71
- 2026-10-28: 70
- 2026-10-27: 70
- 2026-10-26: 69
- 2026-10-25: 69
- 2026-10-24: 68
- 2026-10-23: 68
- 2026-10-22: 67
- 2026-10-21: 67
- 2026-10-20: 67
- 2026-10-19: 66
- 2026-10-18: 66

## Common questions

### What is the Email Auth Checker MCP server?

Email Auth Checker is an MCP server listed in the public MCP registry as dev.workers.quietworklabs.email-auth-check/email-auth-check. SPF, DKIM, DMARC, MTA-STS and domain-expiry checks for any domain, with SPF lookup counts. This page covers its hosted endpoint (https://email-auth-check.quietworklabs.workers.dev/mcp).

### Is the Email Auth Checker MCP server safe to use?

Email Auth Checker scores 74 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the Email Auth Checker MCP server expose?

Email Auth Checker exposes 4 tools: email_auth_report, spf_lookup_count, dmarc_check, domain_expiry. Their descriptions and schemas cost roughly 512 tokens of context every time the server is loaded.

### Does the Email Auth Checker MCP server require authentication?

No. We connected to Email Auth Checker without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the Email Auth Checker MCP server still maintained?

Email Auth Checker is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

### What did VerifyMCP test on the Email Auth Checker MCP server?

VerifyMCP ran 12 checks on Email Auth Checker, covering TLS certificate, Authorization, HSTS header, DNSSEC and 8 more. One item could not be completed, a gap on our side rather than a finding about Email Auth Checker: HTTPS. Supply Chain Security and Provenance & Transparency do not apply to a hosted endpoint, so they were not tested. The score does not measure everything, and the scoring documentation lists what it leaves out.

## Links

- Remote endpoint: https://email-auth-check.quietworklabs.workers.dev/mcp
- Website: https://email-auth-check.quietworklabs.workers.dev/
- Changelog RSS feed: https://verifymcp.io/servers/dev-workers-quietworklabs-email-auth-check-email-auth-check/email-auth-check.xml
- Changelog JSON feed: https://verifymcp.io/servers/dev-workers-quietworklabs-email-auth-check-email-auth-check/email-auth-check/changelog.json
- Trust report (JSON): https://verifymcp.io/servers/dev-workers-quietworklabs-email-auth-check-email-auth-check/email-auth-check.json
- HTML version of this page: https://verifymcp.io/servers/dev-workers-quietworklabs-email-auth-check-email-auth-check/email-auth-check