MCP Mailtrap Server

An MCP server that provides a tool for sending transactional emails via Mailtrap

Setup

Claude Desktop or Cursor

Add the following configuration:

{
  "mcpServers": {
    "mailtrap": {
      "command": "npx",
      "args": ["-y", "mcp-mailtrap"],
      "env": {
        "MAILTRAP_API_TOKEN": "your_mailtrap_api_token",
        "DEFAULT_FROM_EMAIL": "your_sender@example.com"
      }
    }
  }
}

If you are using asdf for managing Node.js you must use absolute path to executable (example for Mac)

{
  "mcpServers": {
    "mailtrap": {
      "command": "/Users/<username>/.asdf/shims/npx",
      "args": ["-y", "mcp-mailtrap"],
      "env": {
        "PATH": "/Users/<username>/.asdf/shims:/usr/bin:/bin",
        "ASDF_DIR": "/opt/homebrew/opt/asdf/libexec",
        "ASDF_DATA_DIR": "/Users/<username>/.asdf",
        "ASDF_NODEJS_VERSION": "20.6.1",
        "MAILTRAP_API_TOKEN": "your_mailtrap_api_token",
        "DEFAULT_FROM_EMAIL": "your_sender@example.com"
      }
    }
  }
}

Claude Desktop config file location

Mac: ~/Library/Application Support/Claude/claude_desktop_config.json

Windows: %APPDATA%Claudeclaude_desktop_config.json

Cursor config file location

Mac: ~/.cursor/mcp.json

Windows: %USERPROFILE%.cursormcp.json

VS Code

Run in Command Palette: Preferences: Open User Settings (JSON)

Then, in the settings file, add the following configuration:

{
  "mcp": {
    "servers": {
      "mailtrap": {
        "command": "npx",
        "args": ["-y", "mcp-mailtrap"],
        "env": {
          "MAILTRAP_API_TOKEN": "your_mailtrap_api_token",
          "DEFAULT_FROM_EMAIL": "your_sender@example.com"
        }
      }
    }
  }
}

[!TIP] Don’t forget to restart your MCP server after changing the “env” section.

Usage

Once configured, you can ask agent to send emails, for example:

• “Send an email to john.doe@example.com with the subject ‘Meeting Tomorrow’ and a friendly reminder about our upcoming meeting.”
• “Email sarah@example.com about the project update, and CC the team at team@example.com”

Available Tools

send-email

Sends a transactional email through Mailtrap.

Parameters:

• to (required): Email address of the recipient
• subject (required): Email subject line
• from (optional): Email address of the sender, if not provided “DEFAULT_FROM_EMAIL” will be used
• text (optional): Email body text, require if “html” is empty
• html (optional): HTML version of the email body, required if “text” is empty
• cc (optional): Array of CC recipient email addresses
• bcc (optional): Array of BCC recipient email addresses
• category (optional): Email category for tracking

Development

1. Clone the repository:

git clone https://github.com/railsware/mailtrap-mcp.git
cd mailtrap-mcp

2. Install dependencies:

npm install

Configuration with Claude Desktop or Cursor

[!TIP] See the location of the config file in the Setup section.

Add the following configuration:

{
  "mcpServers": {
    "mailtrap": {
      "command": "node",
      "args": ["/path/to/mailtrap-mcp/dist/index.js"],
      "env": {
        "MAILTRAP_API_TOKEN": "your_mailtrap_api_token",
        "DEFAULT_FROM_EMAIL": "your_sender@example.com"
      }
    }
  }
}

If you are using asdf for managing Node.js you should use absolute path to executable:

(example for Mac)

{
  "mcpServers": {
    "mailtrap": {
      "command": "/Users/<username>/.asdf/shims/node",
      "args": ["/path/to/mailtrap-mcp/dist/index.js"],
      "env": {
        "PATH": "/Users/<username>/.asdf/shims:/usr/bin:/bin",
        "ASDF_DIR": "/opt/homebrew/opt/asdf/libexec",
        "ASDF_DATA_DIR": "/Users/<username>/.asdf",
        "ASDF_NODEJS_VERSION": "20.6.1",
        "MAILTRAP_API_TOKEN": "your_mailtrap_api_token",
        "DEFAULT_FROM_EMAIL": "your_sender@example.com"
      }
    }
  }
}

VS Code

[!TIP] See the location of the config file in the Setup section.

{
  "mcp": {
    "servers": {
      "mailtrap": {
        "command": "node",
        "args": ["/path/to/mailtrap-mcp/dist/index.js"],
        "env": {
          "MAILTRAP_API_TOKEN": "your_mailtrap_api_token",
          "DEFAULT_FROM_EMAIL": "your_sender@example.com"
        }
      }
    }
  }
}

Testing

You can test the server using the MCP Inspector:

npm run dev

Contributing

Bug reports and pull requests are welcome on GitHub. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

The package is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Mailtrap project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.