# Lettio MCP (npm · @lettio/mcp)

Private, EU-hosted email for AI agents over JMAP: read, search, reply, organize, send.

- Trust score: 74/100 (medium)
- Change this week: +4
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-09-25

## Components

- remote · `mcp.lettio.eu`: 28/100, [markdown](https://verifymcp.io/servers/eu-lettio-mcp/mcp.md), [page](https://verifymcp.io/servers/eu-lettio-mcp/mcp)
- npm · `@lettio/mcp`: 74/100 (this document), [markdown](https://verifymcp.io/servers/eu-lettio-mcp/lettio-mcp.md), [page](https://verifymcp.io/servers/eu-lettio-mcp/lettio-mcp)

## Channel facts

- Registry: `npm`
- Package: `@lettio/mcp`
- Version: `0.1.2`
- Transport: `stdio`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, 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 2026-09-25.

- **Supply Chain Security**: 98/100
  - No malware found by supply-chain analysis.
  - No known CVEs affecting this package version or its production dependencies.
  - No install/post-install scripts declared.
  - 31 of 96 dependencies flagged as unhealthy.
- **Provenance & Transparency**: 45/100
  - Source repository is publicly reachable at the declared URL.
  - Provenance check failed: no build-provenance attestation is published.
  - Clear OSI-approved license (MIT).
  - Actively maintained (last published 9 days ago).
  - Disclosure check failed: no security disclosure policy was found in the source repository.
- **Schema Quality & AI Usability**: 82/100
  - AI-judged instruction clarity (excellent).
  - Tool/resource definitions use about 626 tokens (~62/item across 10 items; 10 tools + 0 resources), lean.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 33/100
  - Stability observed for 10 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**: 75/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - 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.
  - An AI judge read all 10 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 Lettio MCP server?

Lettio MCP runs locally as an npm package, launched with npx -y @lettio/mcp. 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 eu-lettio-mcp -- npx -y @lettio/mcp
```

### Cursor

```json
{
  "mcpServers": {
    "eu-lettio-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@lettio/mcp"
      ]
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "eu-lettio-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@lettio/mcp"
      ]
    }
  }
}
```

### Codex

```bash
codex mcp add eu-lettio-mcp -- npx -y @lettio/mcp
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "eu-lettio-mcp": {
      "type": "local",
      "command": [
        "npx",
        "-y",
        "@lettio/mcp"
      ],
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add eu-lettio-mcp --command npx --arg -y --arg @lettio/mcp
```

### Hermes

```yaml
mcp_servers:
  eu-lettio-mcp:
    command: "npx"
    args: ["-y", "@lettio/mcp"]
```

### Netclaw

```json
{
  "McpServers": {
    "eu-lettio-mcp": {
      "Transport": "stdio",
      "Command": "npx",
      "Arguments": [
        "-y",
        "@lettio/mcp"
      ]
    }
  }
}
```

### Vellum

```bash
assistant mcp add eu-lettio-mcp -t stdio -c npx -a -y @lettio/mcp
```

### Other

```json
{
  "mcpServers": {
    "eu-lettio-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@lettio/mcp"
      ]
    }
  }
}
```

## 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.

### 2026-09-25 (score 74, 0)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-09-24 (score 74, +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.

### 2026-09-23 (score 73, +3)

- [functional improvement] Stability: unverified → 0.27

### 2026-09-22 (score 70, 0)

- [functional regression] Security disclosure: unverified → fail

### 2026-09-21 (score 70, 0)

- [functional regression] Security disclosure: fail → unverified

### 2026-09-17 (score 70, +15)

- [security improvement] Malware scan: unverified → pass

### 2026-09-15 (score 55)

First indexed and scored.

## MCP tools (10)

### `list_accounts` (~21 tokens)

List the Lettio mailboxes this server is configured to access.

### `list_recent_emails` (~84 tokens)

List the most recent emails in a Lettio mailbox (defaults to the inbox).

Input parameters:

- `account` (string): Which configured account to use. Omit to use the first.
- `limit` (integer): How many messages (default 10).
- `mailbox` (string): Mailbox role or name, e.g. "inbox", "sent". Default inbox.

### `search_emails` (~63 tokens)

Search a Lettio mailbox by free-text query (matches sender, subject and body).

Input parameters:

- `account` (string): Which configured account to use.
- `limit` (integer): How many results (default 10).
- `query` (string, required): Text to search for.

### `read_email` (~50 tokens)

Read the full content of one email by its id (get ids from list/search first).

Input parameters:

- `account` (string): Which configured account the email belongs to.
- `id` (string, required): The email id.

### `send_email` (~77 tokens)

Send an email from a Lettio mailbox. Use deliberately — this really sends.

Input parameters:

- `account` (string): Which configured account to send from.
- `body` (string, required): Plain-text body.
- `cc` (array): Optional Cc recipients.
- `subject` (string, required): Subject line.
- `to` (array, required): Recipient email addresses.

### `list_mailboxes` (~40 tokens)

List the folders (mailboxes) in a Lettio account, with message and unread counts.

Input parameters:

- `account` (string): Which configured account to use.

### `reply_email` (~87 tokens)

Reply to an email, keeping it in the same conversation thread. Sends as the mailbox only.

Input parameters:

- `account` (string): Which configured account the email belongs to.
- `body` (string, required): Plain-text reply body.
- `id` (string, required): The id of the email to reply to.
- `reply_all` (boolean): Also reply to the other recipients (Cc them). Default false.

### `set_read_status` (~57 tokens)

Mark an email as read or unread.

Input parameters:

- `account` (string): Which configured account the email belongs to.
- `id` (string, required): The email id.
- `read` (boolean, required): true to mark read, false to mark unread.

### `flag_email` (~59 tokens)

Flag (star) or unflag an email.

Input parameters:

- `account` (string): Which configured account the email belongs to.
- `flagged` (boolean, required): true to flag/star, false to remove the flag.
- `id` (string, required): The email id.

### `move_email` (~88 tokens)

Move an email to another folder. Use "archive" to archive, "trash" to move to Trash (reversible), or a folder name.

Input parameters:

- `account` (string): Which configured account the email belongs to.
- `id` (string, required): The email id.
- `mailbox` (string, required): Target folder: role like "archive", "trash", "inbox", or a folder name.

## Diagnostics

Captured diagnostic sections: Provenance, Dependencies. The full working is on the page: https://verifymcp.io/servers/eu-lettio-mcp/lettio-mcp#diagnostics

## Score history

- 2026-09-25: 74
- 2026-09-24: 74
- 2026-09-23: 73
- 2026-09-22: 70
- 2026-09-21: 70
- 2026-09-20: 70
- 2026-09-19: 70
- 2026-09-18: 70
- 2026-09-17: 70
- 2026-09-16: 55
- 2026-09-15: 55

## Common questions

### What is the Lettio MCP server?

Lettio MCP is listed in the public MCP registry as eu.lettio/mcp. Private, EU-hosted email for AI agents over JMAP: read, search, reply, organize, send. This page covers its npm package (@lettio/mcp).

### Is the Lettio MCP server safe to use?

Lettio MCP scores 74 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 25 September 2026. It declares no install or post-install scripts. 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 Lettio MCP server expose?

Lettio MCP exposes 10 tools: list_accounts, list_recent_emails, search_emails, read_email, send_email, and 5 more. Their descriptions and schemas cost roughly 626 tokens of context every time the server is loaded.

### Is the Lettio MCP server still maintained?

Lettio MCP is still listed as active in the MCP registry. We last reached this channel on 25 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

### What licence is the Lettio MCP server under?

Lettio MCP declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.

## Links

- npm package: https://www.npmjs.com/package/@lettio/mcp
- Socket report: https://socket.dev/npm/package/@lettio/mcp
- Repository: https://github.com/lettio-eu/mcp
- Changelog RSS feed: https://verifymcp.io/servers/eu-lettio-mcp/lettio-mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/eu-lettio-mcp/lettio-mcp.json
- HTML version of this page: https://verifymcp.io/servers/eu-lettio-mcp/lettio-mcp