InboxGuards Email Check
REMOTE · API.INBOXGUARDSTEST.COM
Check emails before you send, and get a $1 SPF/DKIM/DMARC fix plan for your domain. Pay per call.
Available components
Last scanned (17 hours ago)
Scores higher than 59% of remote servers
Reachable. Last reached 18 Oct 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. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one. 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 Usability70
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 692 tokens (~173/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 Management20
- Stability observed for 6 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 current MCP spec version (2026-07-28).Pass
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.
- 18 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 17 to 20. That category is still filling its 30-day observation window: 5 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.
- 16 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 10 to 13. That category is still filling its 30-day observation window: 3 days of observed history at the previous scan, 4 at this one. The score rises as the window fills, whether or not the server changes.
- 14 Oct 26 0
- The server rewrote its instructions, which are the text every model session reads security
- Schema quality: pass → fail ▼ functional
- Schema quality: good → excellent functional
- Server version: 1.1.0 → 1.2.0 functional
- New tool “email_fix_plan” functional
- 13 Oct 26 +10
- Authorization: unverified → partial ▲ security
- The server rewrote its instructions, which are the text every model session reads security
- Tool “check_email_address” rewrote its description, which is the text the model reads security
- Tool “pricing” rewrote its description, which is the text the model reads security
- Tool “validate_email” rewrote its description, which is the text the model reads security
- Schema quality: 47 → 132 ▼ functional
- Tool coverage: 50% → 100% ▲ functional
- Stability: unverified → 0.03 ▲ functional
- Server version: 1.0.0 → 1.1.0 functional
- “validate_email” reworded the description of “email” cosmetic
- 12 Oct 26 57
First indexed and scored.
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 18 Oct 2026 · Probed https://api.inboxguardstest.com/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=inboxguardstest.com | CN=WE1,O=Google Trust Services,C=US | 10 Oct 2026 | 8 Jan 2027 | ECDSA 256 | ECDSA-SHA256 | 4ac1adca8d32013c0e0ac345b56cfa9e |
| SANs: inboxguardstest.com, api.inboxguardstest.com, *.api.inboxguardstest.com | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of api.inboxguardstest.com. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| com. | present | 19718 | 13 | Verified |
| inboxguardstest.com. | absent | 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://api.inboxguardstest.com/mcp | Verified | 200 | |
| http (plaintext) | http://api.inboxguardstest.com/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 →
check_email_address ~195
Check one email address before you send to it: syntax, whether the domain accepts mail (MX, null MX or implicit A record), a disposable-domain flag (public CC0 list of about 9,900 domains), a role-account flag (info@, support@, noreply@...) and a free-provider flag. Returns a verdict of ok, risky or undeliverable with plain reasons. Use validate_email first if you only need syntax. No SMTP probe is made and no mail is sent, so it cannot confirm the mailbox exists. The address is not stored or logged. Read-only; one live DNS lookup via Cloudflare DoH. Costs $0.005 USDC per call via x402 (payment goes in _meta["x402/payment"]); invalid input or a DNS failure returns an error and is not charged.
| Name | Type | Req | Description |
|---|---|---|---|
| string | yes | Email address to check, e.g. jane@example.com |
No output schema declared.
No examples provided.
email_fix_plan ~269
Get an email security fix plan for one domain: the exact SPF, DKIM and DMARC DNS records to publish (create / replace / keep, record name, value and why), in order, plus click-path steps for the domain's DNS host (Cloudflare, GoDaddy, Route 53, Namecheap, Squarespace/Google, Vercel and others). Reads live MX, NS, SPF, DKIM and DMARC; detects Google Workspace, Microsoft 365, Zoho, Proton, Fastmail, GoDaddy and Cloudflare Email Routing; merges SPF within the 10-lookup limit, keeps existing senders, and stages DMARC none -> quarantine -> reject. Domains that send no mail get a lock-down set. Use it when mail lands in spam, before a DMARC rollout, or for a client. DKIM keys are generated by the mail provider, so for those it gives the exact console path. Read-only; nothing is stored. Costs $1 USDC per call via x402 (payment goes in _meta["x402/payment"]); invalid input, an unknown domain or a DNS failure returns an error and is not charged.
| Name | Type | Req | Description |
|---|---|---|---|
| domain | string | yes | Domain to fix, e.g. example.com (an email address or URL on it also works) |
No output schema declared.
No examples provided.
pricing ~47
Free. Return the price of check_email_address (and of the HTTP-only email test report), the payment network (Base) and the receiving address. No input, no network request, no payment.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
validate_email ~62
Free. Check the syntax of an email address offline and get the normalized address and domain, before paying for check_email_address. No DNS lookup, no network request, no payment.
| Name | Type | Req | Description |
|---|---|---|---|
| string | yes | Email address to check, e.g. jane@example.com |
No output schema declared.
No examples provided.
How do I install the InboxGuards Email Check MCP server?
InboxGuards Email Check is a hosted endpoint at https://api.inboxguardstest.com/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 · api.inboxguardstest.com
claude mcp add --transport http com-inboxguardstest-api-email 'https://api.inboxguardstest.com/mcp'
What is the InboxGuards Email Check MCP server?
InboxGuards Email Check is an MCP server listed in the public MCP registry as com.inboxguardstest.api/email. Check emails before you send, and get a $1 SPF/DKIM/DMARC fix plan for your domain. Pay per call. This page covers its hosted endpoint (https://api.inboxguardstest.com/mcp).
Is the InboxGuards Email Check MCP server safe to use?
InboxGuards Email Check scores 69 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 InboxGuards Email Check MCP server expose?
InboxGuards Email Check exposes 4 tools: validate_email, pricing, check_email_address, email_fix_plan. Their descriptions and schemas cost roughly 573 tokens of context every time the server is loaded.
Does the InboxGuards Email Check MCP server require authentication?
No. We connected to InboxGuards Email Check without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the InboxGuards Email Check MCP server still maintained?
InboxGuards Email Check is still listed as active in the MCP registry. We last reached this channel on 18 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.