outlook-triage-mcp

MCP server for Microsoft 365 mail — search, classify, and triage your inbox from Claude via Microsoft Graph: daily-briefing digest, idempotent inbox-rule provisioning, attachment extraction. Device-code auth, read-only by default.

🇺🇸 English

Your inbox, triaged by Claude — without handing anyone your password. This MCP server connects Claude (Code or Desktop) to a Microsoft 365 mailbox through Microsoft Graph, using device-code sign-in and a local token cache. It classifies mail with deterministic keyword heuristics (no LLM calls at runtime, no message content leaving your machine beyond what you ask Claude to read), builds a morning briefing, and can — only if you explicitly opt in — provision inbox rules idempotently.

Features

• Daily briefing — classifies the last N hours of inbox mail into urgent / action_needed / fyi / newsletter and renders a Markdown digest. Heuristics are deterministic and configurable (env vars or a JSON file); messages you already read are never flagged as pending.

• Search & read — Graph $search/$filter message search in any folder; full plain-text bodies; local text extraction from PDF / DOCX / XLSX attachments (pypdf, python-docx, openpyxl — parsing is 100% local).

• Idempotent inbox rules — ensure_inbox_rule converges mailbox state: an already-correct rule triggers zero write calls, a divergent one is patched, a missing one is created (folder included). Run it a hundred times, get one rule.

• Device-code auth — MSAL public-client flow: the auth_status tool hands you a URL and a code; sign in from any browser. Tokens are cached in ~/.local/share/outlook-triage-mcp/ (never in the repo, 0600 permissions) and refreshed silently.

• Read-only by default — the server requests only Mail.Read / MailboxSettings.Read scopes unless you set OUTLOOK_MCP_ENABLE_WRITE=1.

• Retry/backoff — Graph calls honor Retry-After on 429 and back off exponentially on 5xx.

⚠️ Write access

ensure_inbox_rule is the ONLY tool that writes to your mailbox. Every other tool is strictly read-only (and annotated as such in the MCP tool metadata). Rule provisioning is disabled by default: the tool refuses to run until you start the server with OUTLOOK_MCP_ENABLE_WRITE=1 and re-authenticate with write scopes. The server never sends, deletes, moves, or marks messages.

Tools

Example prompts once connected:

"Give me my daily briefing for the last 48 hours." "Search my inbox for messages about the Q3 invoice and read the newest one, including attachments." "Make sure there's a rule moving everything from recruiting@ to a Recruiters folder." (requires write mode)

How it works

flowchart LR
    subgraph Claude["Claude (Code / Desktop)"]
        C[MCP client]
    end
    subgraph Server["outlook-triage-mcp (local)"]
        T[FastMCP tools]
        H[Heuristic classifier<br/>deterministic, no LLM]
        A[MSAL device-code auth<br/>token cache ~/.local/share]
        G[Graph client<br/>retry + backoff]
        X[Attachment extraction<br/>PDF / DOCX / XLSX, local]
    end
    M[(Microsoft Graph<br/>Microsoft 365 mailbox)]

    C <-->|stdio JSON-RPC| T
    T --> H
    T --> X
    T --> G
    G --> A
    G <-->|HTTPS, delegated scopes| M

Install

git clone https://github.com/giuseppeferretti/outlook-triage-mcp
cd outlook-triage-mcp
python -m venv .venv && source .venv/bin/activate
pip install -e ".[attachments]"    # attachments extra enables PDF/DOCX/XLSX parsing

Configure Claude

Claude Code:

claude mcp add outlook-triage -- /path/to/.venv/bin/outlook-triage-mcp

Claude Desktop (claude_desktop_config.json):

{
  "mcpServers": {
    "outlook-triage": {
      "command": "/path/to/.venv/bin/outlook-triage-mcp",
      "env": {
        "OUTLOOK_MCP_USER_EMAIL": "you@yourcompany.com"
      }
    }
  }
}

First use: ask Claude to call auth_status, open the verification URL it returns, type the code, done. The token is cached locally; you will rarely need to sign in again.

Configuration (env vars)

Classification file example (classify.json):

{
  "urgent_keywords": ["urgent", "asap", "outage"],
  "action_keywords": ["please review", "sign off"],
  "vip_senders": ["ceo@yourcompany.com"],
  "newsletter_sender_patterns": ["noreply@", "digest@"]
}

Development

pip install -e ".[dev]"
pytest              # all offline: fixture JSON + fake Graph + stdio smoke test
OUTLOOK_MCP_LIVE_TESTS=1 pytest tests/test_graph_live.py   # optional, real Graph

The test suite requires no Microsoft account: classification and rule-idempotency tests run against fake Graph responses, and the MCP smoke test boots the real stdio server with the official SDK client and verifies the tool list and graceful auth-required behavior.

Provenance

This server was extracted from a production Microsoft 365 automation system — a daily-briefing robot and idempotent inbox-rule provisioner that runs every morning for a real controllership workflow. The battle-tested parts were kept (device-code auth with token cache, Graph retry/backoff, write-free classification, converge-don't-duplicate rule provisioning) and the client-specific heuristics were genericized into configurable keyword lists. Case study at portfolio.iterlabs.com.br.

Related MCP server: m365-mcp

🇧🇷 Português

Servidor MCP para e-mail Microsoft 365 — busque, classifique e faça triagem da sua caixa de entrada pelo Claude via Microsoft Graph. Autenticação por device-code (sem senha no servidor), token em cache local, somente leitura por padrão.

Recursos

• Briefing diário: classifica as últimas N horas em urgent / action_needed / fyi / newsletter com heurísticas determinísticas (sem LLM em runtime), configuráveis por env ou arquivo JSON. Mensagens já lidas nunca aparecem como pendentes.

• Busca e leitura: pesquisa Graph em qualquer pasta, corpo completo em texto e extração local de texto de anexos PDF / DOCX / XLSX.

• Regras idempotentes: ensure_inbox_rule converge o estado da caixa — regra já correta gera zero chamadas de escrita; nunca duplica regra nem pasta.

• Retry/backoff nas chamadas Graph (respeita Retry-After em 429).

⚠️ Escrita

ensure_inbox_rule é a ÚNICA ferramenta que escreve na caixa. Todas as outras são somente leitura. Escrita fica desabilitada até você definir OUTLOOK_MCP_ENABLE_WRITE=1 e autenticar novamente com escopos de escrita. O servidor nunca envia, exclui, move ou marca mensagens.

Instalação e uso

git clone https://github.com/giuseppeferretti/outlook-triage-mcp
cd outlook-triage-mcp
python -m venv .venv && source .venv/bin/activate
pip install -e ".[attachments]"
claude mcp add outlook-triage -- /caminho/para/.venv/bin/outlook-triage-mcp

No primeiro uso, peça ao Claude para chamar auth_status: ele devolve uma URL e um código — abra no navegador, digite o código e pronto. O token fica em cache em ~/.local/share/outlook-triage-mcp/ (nunca no repositório).

Configuração principal: OUTLOOK_MCP_CLIENT_ID (padrão: client público do Microsoft Graph CLI; registre seu próprio app se o tenant bloquear), OUTLOOK_MCP_TENANT_ID, OUTLOOK_MCP_USER_EMAIL, OUTLOOK_MCP_ENABLE_WRITE e as listas de palavras-chave OUTLOOK_MCP_*_KEYWORDS / OUTLOOK_MCP_VIP_SENDERS.

Testes: pytest roda 100% offline (fixtures JSON + Graph falso + smoke test MCP stdio com o SDK oficial). Testes contra o Graph real são opcionais: OUTLOOK_MCP_LIVE_TESTS=1.

Origem

Extraído de um sistema de automação Microsoft 365 em produção (robô de briefing diário + provisionamento idempotente de regras), com as heurísticas do cliente genericizadas em listas configuráveis. Case em portfolio.iterlabs.com.br.

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