Protonmail MCP Server
This MCP server is provided by amotivv, inc., the creators of Memory Box.
This MCP server provides email sending functionality using Protonmail's SMTP service. It allows both Claude Desktop and Cline VSCode extension to send emails on your behalf using your Protonmail credentials.
Compatibility
This MCP server is compatible with:
- Claude Desktop App : The standalone desktop application for Claude
- Cline VSCode Extension : The Claude extension for Visual Studio Code
The same implementation works across both platforms since they both use the Model Context Protocol (MCP) standard.
Features
- Send emails to one or multiple recipients
- Support for CC and BCC recipients
- Support for both plain text and HTML email content
- Comprehensive error handling and logging
Configuration
The server requires the following environment variables to be set in the MCP settings files for both Claude Desktop and Cline:
Claude Desktop Configuration
Located at: /Users/your-username/Library/Application Support/Claude/claude_desktop_config.json
Cline VSCode Extension Configuration
Located at: /Users/your-username/Library/Application Support/Code/User/globalStorage/saoudrizwan.claude-dev/settings/cline_mcp_settings.json
Both configuration files require the following environment variables:
PROTONMAIL_USERNAME: Your Protonmail email addressPROTONMAIL_PASSWORD: Your Protonmail SMTP password (not your regular login password)PROTONMAIL_HOST: SMTP server hostname (default: smtp.protonmail.ch)PROTONMAIL_PORT: SMTP server port (default: 587 for STARTTLS, 465 for SSL/TLS)PROTONMAIL_SECURE: Whether to use a secure connection (default: "false" for port 587, "true" for port 465)DEBUG: Enable debug logging (set to "true" to see detailed logs, "false" to hide them)
For detailed information about Protonmail's SMTP service, including how to get your SMTP password, please refer to the official Protonmail SMTP documentation.
Usage
Once configured, you can use the MCP server to send emails with the following tool:
send_email
Sends an email using your Protonmail SMTP account.
Parameters:
to: Recipient email address(es). Multiple addresses can be separated by commas.subject: Email subject linebody: Email body content (can be plain text or HTML)isHtml: (Optional) Whether the body contains HTML content (default: false)cc: (Optional) CC recipient(s), separated by commasbcc: (Optional) BCC recipient(s), separated by commas
Example:
<use_mcp_tool>
<server_name>protonmail-mcp</server_name>
<tool_name>send_email</tool_name>
<arguments>
{
"to": "[[email protected]](/cdn-cgi/l/email-protection)",
"subject": "Test Email from Cline",
"body": "This is a test email sent via the Protonmail MCP server.",
"cc": "[[email protected]](/cdn-cgi/l/email-protection)"
}
</arguments>
</use_mcp_tool>
Troubleshooting
If you encounter issues with the MCP server, check the following:
- Ensure your Protonmail SMTP credentials are correct in both configuration files
- Verify that the SMTP port is not blocked by your firewall
- Check if your Protonmail account has any sending restrictions
- Look for error messages in the logs:
* Claude Desktop app logs
* Cline VSCode extension output panel
- Restart the Claude Desktop app or reload the VSCode window after configuration changes
Development
To build the project:
cd protonmail-mcp
npm install
npm run build
To modify the server, edit the files in the src directory and rebuild the project.
Installation
This MCP server can be installed in both Claude Desktop and Cline VSCode extension. Here's how to add it to your environment:
Manual Installation
Clone this repository to your local machine:
git clone https://github.com/your-username/protonmail-mcp.git
cd protonmail-mcp
Install dependencies and build the project:
npm install
npm run build
- Add the server configuration to your MCP settings files (see Configuration section above)
Using Cline to Install from GitHub
Cline can automatically clone and build MCP servers from GitHub repositories. To use this feature:
- Provide Cline with the GitHub repository URL
- Let Cline clone and build the server
- Provide any necessary configuration information (like SMTP credentials)
For detailed instructions on installing MCP servers from GitHub using Cline, see the Cline MCP Server Installation Documentation.
Resources
Finding More MCP Servers
You can find additional MCP servers in these repositories and directories:
License
This project is licensed under the MIT License - see the LICENSE file for details.
