MCP Mailtrap Server

An MCP server that provides tools for sending transactional emails and managing email templates via Mailtrap

Prerequisites

Before using this MCP server, you need to:

1. Create a Mailtrap account
2. Verify your domain
3. Get your API token from Mailtrap API settings
4. Get your Account ID from Mailtrap account management

Required Environment Variables:

• MAILTRAP_API_TOKEN - Required for all functionality
• DEFAULT_FROM_EMAIL - Required for all email sending operations
• MAILTRAP_ACCOUNT_ID - Required for template management operations
• MAILTRAP_TEST_INBOX_ID - Only required for sandbox email functionality

Quick Install

Setup

Claude Desktop or Cursor

Add the following configuration:

*Configuration content*

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

*Configuration content*

Claude Desktop config file location

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

Windows: %APPDATA%\Claude\claude_desktop_config.json

Cursor config file location

Mac: ~/.cursor/mcp.json

Windows: %USERPROFILE%\.cursor\mcp.json

VS Code

Manually changing config

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

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

*Configuration content*

[!TIP]
Don't forget to restart your MCP server after changing the "env" section.

Usage

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

Email Operations:

• "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"
• "Send a sandbox email to test@example.com with subject 'Test Template' to preview how our welcome email looks"

Template Operations:

• "List all email templates in my Mailtrap account"
• "Create a new email template called 'Welcome Email' with subject 'Welcome to our platform!'"
• "Update the template with ID 12345 to change the subject to 'Updated Welcome Message'"
• "Delete the template with ID 67890"

Available Tools

send-email

Sends a transactional email through Mailtrap.

Parameters:

• to (required): Email address(es) of the recipient(s) - can be a single email or array of emails
• 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, required 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 (required): Email category for tracking and analytics

send-sandbox-email

Sends an email to your Mailtrap test inbox for development and testing purposes. This is perfect for testing email templates without sending emails to real recipients.

Parameters:

• to (required): Email address(es) of the recipient(s) - can be a single email or array of emails (will be delivered to your test inbox)
• 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, required 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

[!NOTE]
The MAILTRAP_TEST_INBOX_ID environment variable must be configured for sandbox emails to work. This variable is only required for sandbox functionality and is not needed for regular transactional emails or template management.

create-template

Creates a new email template in your Mailtrap account.

Parameters:

• name (required): Name of the template
• subject (required): Email subject line
• html (or text is required): HTML content of the template
• text (or html is required): Plain text version of the template
• category (optional): Template category (defaults to "General")

list-templates

Lists all email templates in your Mailtrap account.

Parameters:

• No parameters required

update-template

Updates an existing email template.

Parameters:

• template_id (required): ID of the template to update
• name (optional): New name for the template
• subject (optional): New email subject line
• html (optional): New HTML content of the template
• text (optional): New plain text version of the template
• category (optional): New category for the template

[!NOTE]
At least one updatable field (name, subject, html, text, or category) must be provided when calling update-template to perform an update.

delete-template

Deletes an existing email template.

Parameters:

• template_id (required): ID of the template to delete

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:

*Configuration content*

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

(example for Mac)

*Configuration content*

VS Code

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

*Configuration content*

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.