mu-mcp: MCP Server for the mu Mail Indexer

A Model Context Protocol (MCP) server for querying your local mu mail index. This server enables fast, structured mail search from Claude Desktop and other MCP clients.

<img src="assets/claude-screenshot.png" width="500"/>

Features

• Stdio MCP server for easy integration
• Three tools: query, view emails and open attachments (using default OS viewer).
• Fast, flexible mail search using the mu index
• Claude Desktop ready: simple installation and config
• Python, pixi, and MCP SDK based

Installation

Clone this repository and install dependencies:

git clone https://github.com/danielfleischer/mu-mcp.git
cd mu-mcp
pixi install

Usage

Run the MCP Server

With pixi:

pixi run start

Or directly with Python:

python mu_mcp/mu_mcp.py

Claude Desktop Integration

Add to your claude_desktop_config.json:

"mcpServers": {
  "mu_mcp": {
    "command": "pixi",
    "args": [
      "run",
      "--manifest-path",
      "PROJECT_PATH",
      "start"
    ]
  }
}

Query

Ask Claude to find emails, e.g. "Find emails with a PDF attachment that were sent last April and open the PDF", "Show me the email I received from Alice last week", or "Find emails with the subject 'Meeting Notes'".

Development

• [x] Adding a tool to view an email.
• [x] Adding a tool to find and download attachments.