mailindex-mcp

A mail client for an AI agent. Everything you can do in Thunderbird — search, move, mark, delete, draft — over your own index, on your own machine.

Most email MCP servers forward each question straight to IMAP. That answers "show me my last 10 messages" and falls apart on everything else: SEARCH is inconsistent between providers, it cannot see inside attachments, it never tells the model whether it actually searched everything, and it cannot do a thing about what it finds.

So when you ask an assistant to clear eight thousand newsletters out of your inbox, it tells you that would be eight thousand tool calls and suggests you go and do it by hand in the web interface.

This one keeps its own copy of your mail and acts on it:

delete_mail(account_id=3, participants=["[email protected]", ...])
→ matched: 4147, affected: 4147, to: "[Google Mail]/Bin"

One call. One connection. Six seconds. That is the difference between a search box and a mail client.

_{A real question against a live index of about 59,000 messages across six accounts. One string is blurred: a case number belonging to a real filing.}

Why this instead of the other email MCP servers

	This project	Typical email MCP
Can it change anything	Move, mark, delete, draft, manage folders — in bulk, by search	Read-only, or one message per call
Search	Own PostgreSQL index, GIN full-text, stemmed across languages	Live IMAP SEARCH per call
Result completeness	Exact total_count, signed cursors, per-account coverage	Whatever the folder returned
Attachments	Text extracted and indexed at sync time (PDF, DOCX, XLSX, PPTX, OCR)	Base64 into the model's context, or not at all
Attachment binaries	Never stored; refetched through a 5-minute signed URL	Stored on disk or inlined
Transport	Remote HTTP endpoint	Local stdio process on your machine
Setup on the client	Paste a URL	Install a runtime, edit config JSON, store credentials locally
Users	Multi-tenant, every row owner-scoped	Single user
Tool surface	19 tools, all annotated	Frequently 40+

What it costs you, stated up front. You run PostgreSQL and a container. The index is about 28 MB per 1,000 messages — a 50,000-message archive is roughly 1.5 GB — and the image is 1.25 GB because it carries OCR language data. The first sync downloads every message once; search works on what has arrived while the rest continues in the background, and each account reports its own coverage so the model knows what it has not seen yet.

In exchange your assistant can answer questions about mail from years ago, including text inside attachments, and then act on the answer. None of it leaves your machine.

Quickstart

Five minutes, local only, no accounts to create anywhere.

git clone https://github.com/alexanderkrauck/mailindex-mcp.git
cd mailindex-mcp
cp .env.example .env
docker compose up -d