Proton Bridge MCP — Claude Code MCP server: setup & review
Gives AI assistants access to search, inspect, and draft messages in Proton Mail via a local bridge. Keeps email on your drive without third-party exposure.
Open on GitHubWhat Proton Bridge MCP does
The server hooks your assistant into Proton Mail on the local machine. Because Proton uses end-to-end encryption, there is no remote cloud endpoint for assistants to query. Instead, the official Proton Mail Bridge decrypts everything locally and runs IMAP and SMTP on 127.0.0.1. Your email never travels to external servers. Without Proton Mail Bridge running on that local address, the server will not function.
It can search your mailbox, pull text from PDF invoices, and inspect images. Sending and forwarding are guarded by a confirmation prompt. If you prefer to review messages yourself, pass draft=true to save them straight to Drafts. Attachments are locked to specific approved directories, stopping the agent from attaching random personal files from your hard drive.
The poll_folder tool watches for fresh messages. It uses checkpoints alongside UIDVALIDITY markers so folder resyncs do not cause repeated runs. Deleting folders is blocked to keep your mailbox structure intact, and message deletions can only move items to Trash.
What it helps with
- search encrypted emails and read PDF invoice text locally
- create threaded draft replies without sending them immediately
- organise messages with tags and folders across multiple mailboxes
- monitor incoming messages via checkpointed folder polling
Example prompts for the agent
- Find messages with invoice attachments from last month and read the text from the PDFs
- Create a draft reply to the latest thread from my manager using
create_draft - Check new messages in Inbox with
poll_folderand apply the finance label
How to install Proton Bridge MCP
Install
The MCP registry has no launch command for it: see the repository README
Step by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about Proton Bridge MCP
How to set up Proton Bridge MCP in Claude Code?
Setup instructions are available at https://considus.com/proton-bridge-mcp/install/. You must have Proton Mail Bridge actively running locally on 127.0.0.1 for the server to connect.
What does Proton Bridge MCP do?
It provides an interface for assistants to search folders, inspect email text and attachments, and compose replies through Proton Mail. Outgoing messages require explicit confirmation unless saved as drafts.
Can the assistant delete mail or folders permanently?
No, folder deletion is disabled to protect mailbox integrity. Messages cannot be permanently removed either, as the server only allows moving them to Trash.
