Proton Mail MCP

Name: Proton Mail MCP
Author: sethbang

@sethbang

About Proton Mail MCP

Unofficial MCP server for Proton Mail (not affiliated with Proton AG) — send, read, search & organize email over SMTP/IMAP

Basic information

Config

Add this server to your MCP-compatible client using the configuration below.

{
  "mcpServers": {
    "protonmail": {
      "command": "npx",
      "args": [
        "-y",
        "proton-mail-mcp"
      ],
      "env": {
        "PROTONMAIL_USERNAME": "[email protected]",
        "PROTONMAIL_PASSWORD": "your-smtp-password"
      }
    }
  }
}

Tools

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Overview

What is Proton Mail MCP?

A Model Context Protocol (MCP) server that gives AI assistants full access to your Proton Mail account — send, read, search, and organize email over SMTP and IMAP. It is an unofficial, community-built project that integrates with Proton Mail via the standard SMTP submission endpoint and the locally-run Proton Mail Bridge, using no private Proton API.

How to use Proton Mail MCP?

Requires Node.js v24+, a Proton Mail account with an SMTP password, and Proton Mail Bridge running locally for IMAP/read tools. Add proton-mail-mcp to your MCP client's server configuration using npx -y proton-mail-mcp with the PROTONMAIL_USERNAME and PROTONMAIL_PASSWORD environment variables set. Works with any MCP-compatible client (Claude Desktop, Claude Code, Cursor, etc.).

Key features of Proton Mail MCP

Send, reply, forward, and reply-all email via SMTP with threading headers
Read email via IMAP through Proton Mail Bridge
Attachments — send files (base64), download to memory or to disk
Search messages by sender, recipient, subject, body, date, flags, and more
Bulk operations on messages with dry-run preview mode
Folder and label management (create, rename, delete — non-destructive on Proton)
Read-only mode and safety guards (delete moves to Trash by default)

Use cases of Proton Mail MCP

An AI assistant triages an inbox from an MCP client, reading and organizing messages
Automate sending, replying to, and forwarding emails with Markdown body support
Search messages by multiple criteria and perform bulk label or folder updates
Analyze inbox with aggregations like top senders and folder statistics
Manage folders and labels programmatically while keeping messages in their source folders

FAQ from Proton Mail MCP

Is this an official Proton product?

No. This is an independent, community-built MCP server not developed, endorsed, or sponsored by Proton AG. "Proton" and "Proton Mail" are trademarks of Proton AG used only to describe interoperability.

What are the runtime and dependency requirements?

Node.js v24+ is required. For IMAP/read tools (reading email, searching), Proton Mail Bridge must be running locally.

How does the server connect to Proton Mail?

It communicates over the standard SMTP submission endpoint for sending and through the locally-run Proton Mail Bridge for IMAP-based reading and searching. No private Proton API is used.

Does the server have safety features?

Yes. Deletion moves messages to Trash by default. A READONLY=true environment variable enables full read-only mode. All bulk operations support dryRun preview. Path-traversal defense, input validation, credential sanitization, rate limiting, and attachment size limits are also applied.

What authentication is required?

A Proton Mail account with an SMTP password is required. Authentication is configured via the PROTONMAIL_USERNAME and PROTONMAIL_PASSWORD environment variables.