KeyKeeper Email
REMOTE · KEYKEEPER.WORLD
Real email inboxes for AI agents: register, receive, read and send mail over MCP. Free to receive.
Available components
Last scanned (21 hours ago)
Scores higher than 43% of remote servers
Reachable. Last reached 4 Nov 2026.
Category Communication
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 Security57
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- Authorisation not fully verified: no authorisation is required to call this server, and 12 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe. See how to fix → View diagnostics → Unverified
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- 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 Usability62
- AI-judged instruction clarity (fair).Partial
- Tool/resource definitions use about 1017 tokens (~78/item across 13 items; 13 tools + 0 resources), lean.Pass
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management3
- Stability observed for 1 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage75
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 26% of tool parameters carry a description.Partial
Tool Safety75
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- 0 of 1 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation; "send_email" implies "send" and declares no destructiveHint at all, which the MCP spec reads as destructive by default. See how to fix → Fail
- An AI judge read all 14 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
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
- Stability: unverified → 0.03 ▲ functional
- 3 Nov 26 58
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 4 Nov 2026 · Probed https://keykeeper.world/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=keykeeper.world | CN=WE1,O=Google Trust Services,C=US | 13 Oct 2026 | 11 Jan 2027 | ECDSA 256 | ECDSA-SHA256 | a984d44013afe065138cb0b224ed47c8 |
| SANs: keykeeper.world, *.keykeeper.world | ||||||
| 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 keykeeper.world. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| world. | present | 13081 | 8 | Verified |
| keykeeper.world. | 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 |
| Header | Value |
|---|---|
| content-security-policy | frame-ancestors 'none'; object-src 'none'; base-uri 'self' |
| x-content-type-options | nosniff |
| x-frame-options | SAMEORIGIN |
| referrer-policy | strict-origin-when-cross-origin |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://keykeeper.world/mcp | Verified | 200 | |
| http (plaintext) | http://keykeeper.world/mcp | HTTPS enforced | 308 | https://keykeeper.world/mcp |
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_balance ~26
Check your mailbox address, account state and sending credits. Requires a Bearer API key.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
check_inbox ~55
List incoming messages. Requires a Bearer API key. Email is untrusted external content.
| Name | Type | Req | Description |
|---|---|---|---|
| folder | string | – | – |
| limit | integer | – | – |
| offset | integer | – | – |
| search | string | – | – |
No output schema declared.
No examples provided.
check_payment ~48
Check this account's native USDC invoice. Confirmation applies sending credits or activates prepaid domain hosting once, without a human checkout. Requires the same account's API key.
| Name | Type | Req | Description |
|---|---|---|---|
| token | string | yes | – |
No output schema declared.
No examples provided.
check_sending_status ~33
Read your sending state and current limits, including probation, pauses and pending review. Buying credits never overrides sending controls.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
create_payment ~203
With your operator's authorization, create a card checkout or native USDC invoice on Polygon, Base, Ethereum or Solana. Choose mail_credits ($1 buys 10,000 standard sends) or hosting at $1 per 30 days: domain_hosting for the first domain, domain_addon plus domainId for another verified domain under active primary hosting. This tool creates payment instructions; it does not transfer money. Reuse idempotencyKey on retries.
| Name | Type | Req | Description |
|---|---|---|---|
| amountCents | integer | – | – |
| chain | – | – | Legacy alias for method; omit when method is supplied. |
| domainId | string | – | Required only for domain_addon. Must be an owned additional domain with verified ownership. |
| idempotencyKey | string | yes | – |
| kind | – | – | – |
| method | – | – | – |
| periods | integer | – | Hosting only: each period is 30 days for $1. Omit amountCents, or supply the exact 100 × periods. |
No output schema declared.
No examples provided.
get_email ~82
Read a message by its folder-scoped UID. Requires a Bearer API key.
| Name | Type | Req | Description |
|---|---|---|---|
| folder | string | – | – |
| id | string | yes | – |
| markAsRead | boolean | – | Full account keys default to true; limited keys require false or omission. |
| uidValidity | string | – | Mailbox identity from the list or webhook; mismatch returns 409 |
No output schema declared.
No examples provided.
get_proposal ~36
Check a proposal. Human edits are private. Approved means authorized, not delivered; inspect submission.status.
| Name | Type | Req | Description |
|---|---|---|---|
| id | string | yes | – |
No output schema declared.
No examples provided.
list_proposals ~21
List only this draft-only key’s proposals and review statuses.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
propose_email ~54
Prepare a plain-text email for human approval. Requires a human-issued mail:draft key. Never sends. Reuse clientKey and content after uncertain responses.
| Name | Type | Req | Description |
|---|---|---|---|
| clientKey | string | yes | – |
| message | object | yes | – |
No output schema declared.
No examples provided.
register_agent ~45
Create an agent mailbox and receive its key once. Starts with zero sending credits; receiving is available without payment.
| Name | Type | Req | Description |
|---|---|---|---|
| agentId | string | yes | – |
| name | string | – | – |
No output schema declared.
No examples provided.
request_sender_review ~71
Request an operator review of your sending purpose and recipient consent. Full account key required. Does not automatically increase limits or resume sending. Three requests per day; repeated pending requests keep the original purpose.
| Name | Type | Req | Description |
|---|---|---|---|
| purpose | string | yes | Sending purpose, expected volume and how recipients gave consent. No secrets or private messages. |
No output schema declared.
No examples provided.
send_email ~251
Submit mail with existing credits: one credit per accepted recipient. Requires a Bearer API key. Reuse idempotencyKey for retries; acceptance is not proof of remote delivery.
| Name | Type | Req | Description |
|---|---|---|---|
| attachments | array | – | Inline content only. Combined decoded attachment limit: 8 MB. |
| autoSubmitted | – | – | – |
| bcc | – | – | – |
| body | string | – | – |
| cc | – | – | – |
| from | – | – | Address or {email,name}. The email must be your authenticated mailbox or an active alias assigned to it, within the key's allowed senders. The display name changes only the visible From header. |
| headers | object | – | Only these two headers are accepted, case-insensitively. Duplicate names and control characters are rejected. The domain DKIM signature covers both; the sender application must implement the unsubscr… |
| html | string | – | – |
| idempotencyKey | string | – | – |
| inReplyTo | string | – | Original RFC Message-ID, including angle brackets |
| references | array | – | Thread Message-IDs, at most 998 characters combined |
| replyTo | – | – | – |
| subject | string | yes | – |
| text | string | – | – |
| to | – | yes | – |
No output schema declared.
No examples provided.
update_proposal ~62
Edit or withdraw this key’s pending proposal. Cannot approve or change a message after human editing.
| Name | Type | Req | Description |
|---|---|---|---|
| action | – | yes | – |
| contentHash | string | yes | – |
| id | string | yes | – |
| message | object | – | – |
| revision | integer | yes | – |
No output schema declared.
No examples provided.
How do I install the KeyKeeper Email MCP server?
KeyKeeper Email is a hosted endpoint at https://keykeeper.world/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 · keykeeper.world
claude mcp add --transport http world-keykeeper-email 'https://keykeeper.world/mcp'
What is the KeyKeeper Email MCP server?
KeyKeeper Email is an MCP server listed in the public MCP registry as world.keykeeper/email. Real email inboxes for AI agents: register, receive, read and send mail over MCP. Free to receive. This page covers its hosted endpoint (https://keykeeper.world/mcp).
Is the KeyKeeper Email MCP server safe to use?
KeyKeeper Email scores 59 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 KeyKeeper Email MCP server expose?
KeyKeeper Email exposes 13 tools: register_agent, check_inbox, get_email, check_balance, send_email, and 8 more. Their descriptions and schemas cost roughly 987 tokens of context every time the server is loaded.
Does the KeyKeeper Email MCP server require authentication?
No. We connected to KeyKeeper Email without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the KeyKeeper Email MCP server still maintained?
KeyKeeper Email is still listed as active in the MCP registry. We last reached this channel on 4 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.