# googlarz/proton-mail-bridge-client [Health: Active]

**Category:** 💬 Communication  
**Repository:** https://github.com/googlarz/proton-mail-bridge-client  
**GitHub Stars:** 83  
**npm Downloads (last month):** 6995  
**Views:** 0  
**Installs:** 0  
**Upvotes:** 0  
**Directory Page:** https://allmcps.com/mcp/googlarz-proton-mail-bridge-client

## Description
Local-first Proton Mail MCP server and CLI via Proton Mail Bridge: search, read, draft, send, triage threads, answer calendar invitations, reply reminders, multiple accounts, and a local SQLite index. Safety presets from read-only to full, with send confirmation and an outbound-to-self mode.

## Tools
Capabilities this server exposes over MCP:

- **list_remote_drafts** — shows the primary account's remote Proton Drafts folder only

## Claude Desktop Quick Installation
Install path detected from listing signals. Uses `npx` (confidence: high):

```json
"mcpServers": {
  "proton-mail-bridge-client": {
    "command": "npx",
    "args": ["-y","proton-mail-bridge-client"],
    "env": {
      "PROTONMAIL_MODE": "",
      "PROTONMAIL_READ_ONLY": "",
      "PROTONMAIL_TOOL_TIER": ""
    }
  }
}
```

**Requires environment variables:** `PROTONMAIL_MODE`, `PROTONMAIL_READ_ONLY`, `PROTONMAIL_TOOL_TIER` — the values above are empty placeholders; fill in real credentials before running (see the repository for what each one is for).

## Documentation

## What googlarz/proton-mail-bridge-client does

googlarz/proton-mail-bridge-client adds an MCP and command-line interface for Proton Mail accounts exposed by Proton Mail Bridge. It covers common mailbox workflows, including searching and reading messages, preparing and sending mail, managing drafts, triaging threads, moving or archiving messages, handling folders, saving attachments, and responding to calendar invitations. The server also exposes `list_remote_drafts`, which lists the primary account's remote Proton Drafts folder.

A local SQLite index supports full-text mailbox search and tracks read state with the server. Multiple Proton logins or Bridge-exposed addresses can be configured as separate accounts, each with its own index, drafts, and settings. The project includes 116 MCP tools in its full tier and a 25-tool core tier.

## How it works

Proton Mail Bridge must be installed, signed in, and running. The bridge decrypts mail locally and provides the IMAP and SMTP access used by this project; the server does not replace Bridge or connect directly to Proton's remote service. Mail follows a local path from Proton Mail to Bridge, then to the server and the selected AI client.

Claude Desktop, Cline, or another MCP client can invoke the server's mail operations. The same capabilities are available through a CLI for scripts, scheduled jobs, pipelines, diagnostics, and automation without Claude. A `doctor` command checks configured accounts, while `report` produces a diagnostic summary.

Safety behavior is configurable. `PROTONMAIL_MODE` provides read-only, drafts, assisted, and full presets; draft mode allows reading, searching, and preparing drafts while blocking sending and deletion. Read-only mode prevents mailbox changes, and additional controls include send gating, destructive-action confirmation, and per-action allowlists.

## Setup and configuration

Install Proton Mail Bridge and copy its generated Bridge password from the Bridge application. This password is separate from the Proton account password. Node.js 24 or later is required for the npm installation and the bundled setup flow.

For Claude Desktop, users can open a platform-specific MCP bundle or install the npm package globally and run `proton-mail-bridge-client setup-claude-desktop`. The setup process can check Bridge ports and write the client configuration. Supported bundle targets include macOS Apple silicon and Intel, Linux x64 and ARM64, and Windows x64. After changing the Claude Desktop configuration, fully quit and reopen the application.

Optional settings cover Bridge IMAP and SMTP host or port, read-only operation, sending permissions, signatures, additional accounts, data and download directories, and the selected tool tier. The documented environment controls include `PROTONMAIL_MODE`, `PROTONMAIL_READ_ONLY`, and `PROTONMAIL_TOOL_TIER`.

## Tools and capabilities

- Search a local index across the mailbox.
- Read, draft, send, reply to, archive, move, and triage messages and threads.
- Batch-act on threads and manage folders.
- Find and save attachments, including PDF text and pictures.
- Answer calendar invitations.
- List remote drafts for the primary account.
- Run mailbox rules that can propose filters and cleanup, preview changes, and forward by condition.
- Configure per-account autoresponders with previews, approval drafts, and working hours.
- Use the CLI directly, including a generic tool passthrough and commands for diagnostics.

## Limitations and notes

Bridge must remain installed, signed in, and running for mailbox access. The server communicates with Bridge over local IMAP and SMTP on the machine where it runs. Email content requested by an AI client is visible to that client; when Claude Desktop uses Anthropic's hosted API, conversation content can be sent to Anthropic under its privacy policy. A self-hosted or local-only model can keep that content on the machine.

Sending is not automatically enabled by every safety configuration. Draft and read-only modes are intended for review or browsing, and automatic replies are off by default. The local index and account data are maintained separately for each configured account.

_Full upstream README: https://allmcps.com/mcp/googlarz-proton-mail-bridge-client/readme_