MCP 服务器

MCP Email Server

An HTTP streaming MCP server for sending emails via Gmail using nodemailer, supporting HTML content and CC/BCC recipients.

README

MCP Email Server (HTTP Streaming)

This is a test service. To ensure security, enable authentication.

An HTTP streaming MCP (Model Context Protocol) server for sending emails via Gmail. Deployable to Cloud Foundry or any Node.js hosting platform.

Features

HTTP streaming transport for remote MCP connections
MCP tool: send_email for sending emails
Support for To, CC, and BCC recipients
HTML body support
Cloud Foundry ready
Health check endpoint

Prerequisites

Node.js 22.x or higher
Gmail account with App Password enabled
Cloud Foundry CLI (for CF deployment)

Gmail Setup

To use this server, you need to generate a Gmail App Password:

Go to your Google Account settings
Navigate to Security → 2-Step Verification
Scroll down to "App passwords"
Generate a new app password for "Mail"
Save the 16-character password

Installation

npm install

Local Development

Set environment variables:

export GMAIL_USER=your-email@gmail.com
export GMAIL_PASSWORD=your-app-password
export PORT=3000

Start the server:

npm start

The server will start on port 3000 (or PORT environment variable).

Endpoints:

Health check: http://localhost:3000/health
MCP endpoint: http://localhost:3000/mcp

Cloud Foundry Deployment

cf login

Set environment variables:

cf set-env mcp-email-server GMAIL_USER your-email@gmail.com
cf set-env mcp-email-server GMAIL_PASSWORD your-app-password

Push the application:

cf push

Get your app URL:

cf app mcp-email-server

Your MCP server will be available at: https://your-app.cfapps.io/mcp

MCP Client Configuration

Claude Desktop

Add to your Claude Desktop configuration file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "email": {
      "transport": "http",
      "url": "https://your-app.cfapps.io/mcp"
    }
  }
}

Claude Code CLI

Add to your MCP settings file (~/.claude/mcp_settings.json):

{
  "mcpServers": {
    "email": {
      "transport": "http",
      "url": "https://your-app.cfapps.io/mcp"
    }
  }
}

Custom MCP Client

Send POST requests to the MCP endpoint:

const response = await fetch('https://your-app.cfapps.io/mcp', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    jsonrpc: '2.0',
    id: 1,
    method: 'tools/list',
    params: {}
  })
});

MCP Tool Usage

send_email

Send an email via Gmail with HTML support.

Required Parameters:

to (string): Recipient email address (comma-separated for multiple)
subject (string): Email subject line
body (string): Email body (HTML supported)

Optional Parameters:

cc (string): CC recipients (comma-separated)
bcc (string): BCC recipients (comma-separated)

Example Usage in Claude:

Send an email to john@example.com with subject "Meeting Tomorrow" and body "<h1>Reminder</h1><p>Don't forget our meeting at 2pm!</p>"

Claude will use the send_email tool to send the email through your deployed server.

API Endpoints

GET /health

Health check endpoint

Response:

{
  "status": "ok",
  "service": "mcp-email-server",
  "gmail_configured": true
}

POST /mcp

HTTP streaming endpoint for MCP protocol communication

This is the main endpoint that MCP clients connect to.

Request format:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list",
  "params": {}
}

Tool Schema

{
  "name": "send_email",
  "description": "Send an email via Gmail. Supports HTML content in the body and optional CC/BCC recipients.",
  "inputSchema": {
    "type": "object",
    "properties": {
      "to": {
        "type": "string",
        "description": "Recipient email address"
      },
      "subject": {
        "type": "string",
        "description": "Email subject line"
      },
      "body": {
        "type": "string",
        "description": "Email body content (HTML is supported)"
      },
      "cc": {
        "type": "string",
        "description": "CC recipients (comma-separated)"
      },
      "bcc": {
        "type": "string",
        "description": "BCC recipients (comma-separated)"
      }
    },
    "required": ["to", "subject", "body"]
  }
}

Testing

Test the health endpoint:

curl https://your-app.cfapps.io/health

Test listing tools:

curl -X POST https://your-app.cfapps.io/mcp \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "tools/list",
    "params": {}
  }'

Test sending an email:

curl -X POST https://your-app.cfapps.io/mcp \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 2,
    "method": "tools/call",
    "params": {
      "name": "send_email",
      "arguments": {
        "to": "recipient@example.com",
        "subject": "Test Email",
        "body": "<h1>Hello</h1><p>This is a test email.</p>"
      }
    }
  }'