Mailer MCP

A Model Context Protocol (MCP) server for sending emails. This server is designed to be completely SMTP provider agnostic, allowing you to use any SMTP relay service of your choice (Gmail, SendGrid, Mailgun, SMTP2Go, etc.) by simply configuring the appropriate environment variables. The server provides tools for sending emails through SMTP using environment variables for configuration.

Features

• Send emails to specified recipients
• Test email functionality
• Environment variable configuration
• Proper error handling and logging
• TypeScript implementation for type safety

Installation

1. Clone the repository:

git clone https://github.com/yourusername/mailer-mcp.git
cd mailer-mcp

2. Install dependencies:

npm install

3. Build the project:

npm run build

Configuration

The server requires the following environment variables to be set in the MCP configuration:

Variable	Description	Example
SMTP_HOST	SMTP server hostname	smtp.example.com
SMTP_PORT	SMTP server port	587
SMTP_USER	SMTP username	user@example.com
SMTP_PASSWORD	SMTP password	password123
EMAIL_FROM	Sender email address	sender@example.com

Optional environment variables:

Variable	Description	Default
SMTP_SECURE	Use secure connection (TLS)	false
SMTP_REJECT_UNAUTHORIZED	Reject unauthorized TLS certificates	true
SMTP_TIMEOUT	Connection timeout in milliseconds	10000

MCP Configuration

Add the following to your Cline MCP settings configuration file:

"email-server": {
  "autoApprove": [],
  "disabled": false,
  "timeout": 60,
  "command": "node",
  "args": [
    "path/to/mailer-mcp/dist/index.js"
  ],
  "env": {
    "SMTP_HOST": "smtp.example.com",
    "SMTP_PORT": "587",
    "SMTP_USER": "user@example.com",
    "SMTP_PASSWORD": "password123",
    "EMAIL_FROM": "sender@example.com"
  },
  "transportType": "stdio"
}

Available Tools

send_email

Sends an email to a specified recipient.

Parameters:

• recipient (string, required): Email address of the recipient
• body (string, required): Email body content

Example:

{
  "recipient": "recipient@example.com",
  "body": "Hello, this is a test email from the MCP server."
}

test_email

Sends a test email to verify the configuration.

Parameters: None

Development

1. Start the TypeScript compiler in watch mode:

npm run dev

2. Make your changes to the source files in the src directory.

3. The TypeScript compiler will automatically recompile the files when changes are detected.

License

MIT