@deus-ai/outlook-mcp

Standalone Outlook (Microsoft 365) MCP server. Connects to a mailbox over the Microsoft Graph API and exposes it as an MCP channel: it polls the Inbox for unread mail, forwards each conversation to the MCP client as an incoming message, and sends replies in-thread.

It implements the ChannelProvider contract from @deus-ai/channel-core and is the Outlook analog of @deus-ai/gmail-mcp.

Configuration (env vars)

| Var | Default | Meaning | |-----|---------|---------| | OUTLOOK_CREDENTIALS_DIR | ~/.outlook-mcp/ | Holds app-credentials.json + token.json | | OUTLOOK_POLL_INTERVAL_MS | 60000 | Inbox poll interval | | LOG_LEVEL | info | pino log level (stderr) |

app-credentials.json holds your Azure AD app registration:

{ "clientId": "<application-client-id>", "tenantId": "<directory-tenant-id>" }

Auth is delegated, device-code only (a user signs in once); the public-client app registration must have Allow public client flows enabled. The confidential (clientSecret / app-only) flow is not supported.

One-time sign-in

npm install && npm run build
node dist/index.js auth   # device-code flow — open the URL, enter the code

This seeds token.json (with a refresh token) so the server acquires access tokens silently afterwards.

Run

node dist/index.js   # stdio MCP server; auto-connects if credentials exist

JID format

Each conversation maps to outlook:<conversationId>.

Known limitation

A reply can only be sent to a conversation the server has already seen in a poll cycle (the reply target message id is cached on inbound). A reply to a thread received before the process started is logged and skipped.