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.
Available components
Last scanned (12 hours ago)
Scores higher than 62% of remote servers
Reachable. Last reached 5 Nov 2026.
Category Security
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. How we score → Why this is hard to score →
Endpoint Security63
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- 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. See how to fix → View diagnostics → Partial
- HTTPS enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement. View diagnostics → Unverified
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability69
- AI-judged instruction clarity (excellent).Pass
- 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. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management60
- Stability observed for 18 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 4 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 5 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Checks we ran (12)
- TLS certificate
- Authorization
- HSTS header
- DNSSEC
- Transport
- Schema quality
- Stability
- Tool coverage
- Injection markers
- Destructive annotations
- Judged manipulation
- MCP protocol
Checks we could not complete (1)
These are gaps on our side, not findings about this hosted endpoint. We only credit what we can confirm, so a category made up entirely of them scores 0.
- HTTPS in Endpoint SecurityHTTPS enforcement could not be verified: the plaintext port answered with HTTP 405, which proves neither a plaintext path nor enforcement.
Does not apply to this hosted endpoint (2)
- Supply Chain SecurityScored on package channels only. This is a hosted endpoint, so there is nothing to install or inspect.
- Provenance & TransparencyScored on package channels only. This is a hosted endpoint, so there is nothing to install or inspect.
The score does not measure everything. What the score does not measure →
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 4 Nov 26 +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.
- 2 Nov 26 +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.
- 31 Oct 26 +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.
- 29 Oct 26 +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.
- 27 Oct 26 +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.
- 25 Oct 26 +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.
- 23 Oct 26 +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.
- 20 Oct 26 +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.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 5 Nov 2026 · Probed https://email-auth-check.quietworklabs.workers.dev/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=quietworklabs.workers.dev | CN=YE1,O=Let's Encrypt,C=US | 18 Oct 2026 | 16 Jan 2027 | ECDSA 256 | ECDSA-SHA384 | 6203662d048034ad6156b34972b93b5ae9a |
| SANs: *.quietworklabs.workers.dev, quietworklabs.workers.dev | ||||||
| CN=YE1,O=Let's Encrypt,C=US (CA) | CN=Root YE,O=ISRG,C=US | 3 Sept 2025 | 2 Sept 2028 | ECDSA 384 | ECDSA-SHA384 | 5ddd70dd31f801c85c186a7a04b80afe |
| CN=Root YE,O=ISRG,C=US (CA) | CN=ISRG Root X2,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | ECDSA 384 | ECDSA-SHA384 | 872165fc34b6e5fba8add5b3705fb53a |
| CN=ISRG Root X2,O=Internet Security Research Group,C=US (CA) | CN=ISRG Root X1,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | ECDSA 384 | SHA256-RSA | 6c8f1dc727c7117f7baf853ac980f9cd |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of email-auth-check.quietworklabs.workers.dev. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | Trust anchor | 20326, 38696 | 8, 8 | Verified |
| dev. | DS published | 60074 | 8 | Verified |
| workers.dev. | No DS | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://email-auth-check.quietworklabs.workers.dev/mcp | Verified | 200 | |
| http (plaintext) | http://email-auth-check.quietworklabs.workers.dev/mcp | Inconclusive | 405 |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
dmarc_check DMARC record parse and validation ~104
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.
| Name | Type | Req | Description |
|---|---|---|---|
| domain | string | yes | Domain to check |
No output schema declared.
No examples provided.
domain_expiry Domain registration and expiry date via RDAP ~120
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.
| Name | Type | Req | Description |
|---|---|---|---|
| domain | string | yes | Domain name |
No output schema declared.
No examples provided.
email_auth_report Full email authentication report for a domain ~174
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.
| Name | Type | Req | Description |
|---|---|---|---|
| domain | string | yes | Domain (or email address) to check |
| selectors | string | – | Optional comma list of DKIM selectors to probe (max 10) |
No output schema declared.
No examples provided.
spf_lookup_count SPF record tree with RFC 7208 lookup and void-lookup counts ~114
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.
| Name | Type | Req | Description |
|---|---|---|---|
| domain | string | yes | Domain to check |
No output schema declared.
No examples provided.
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.
remote · email-auth-check.quietworklabs.workers.dev
claude mcp add --transport http dev-workers-quietworklabs-email-auth-check-email 'https://email-auth-check.quietworklabs.workers.dev/mcp'
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.