Outlook SNDS MCP server

Outlook SNDS MCP

An MCP server that brings the Outlook.com Smart Network Data Services (SNDS) REST API into Claude / Cowork / Claude Desktop and any other MCP client.

Sign in once with your Microsoft account — the server handles the full OAuth 2.0 authorization-code + PKCE flow over a loopback (http://localhost) redirect, caches the tokens, and refreshes them automatically. Then just ask for your IP reputation data.

SNDS gives senders per-IP insight into how Outlook.com sees their mail:

volume, complaint rates, spam-filter verdicts, trap hits, and block/bot status.

Built & maintained by the Postmaster+ team at OptiPub.

Install

From a release (recommended)

1. Download outlook-snds.mcpb from the latest release.
2. In Cowork / Claude Desktop: Settings → Capabilities → install extension, pick the file (or just double-click it).
3. No configuration required.

From source — see Build.

Use with other MCP clients (Cursor, VS Code, Windsurf, …)

The .mcpb is just a packaging convenience for Claude Desktop / Cowork. Underneath, this is a standard stdio MCP server, so any client that runs local MCP servers can use it directly — no .mcpb required. Just point the client at server/index.js.

Clone or download the repo first, then add a server entry:

Cursor — edit ~/.cursor/mcp.json (global) or .cursor/mcp.json (per project):

{
  "mcpServers": {
    "outlook-snds": {
      "command": "node",
      "args": ["/absolute/path/to/outlook-snds-mcp/server/index.js"]
    }
  }
}

VS Code (.vscode/mcp.json), Windsurf, Claude Desktop (manual config), and most other clients use the same command + args shape — only the config file location differs. Optional environment overrides (see Configuration) go in an "env": { ... } object.

The first tool call opens your browser for the SNDS sign-in, exactly as in Cowork — the localhost OAuth loopback works on any local desktop client.

Remote-only clients (e.g. Perplexity, ChatGPT connectors): these accept

only a remote HTTPS MCP server URL, not a local command, so this stdio build

can't be added directly. Using it there would require hosting it as a remote

server with a web-based OAuth redirect.

Usage

Run snds_authenticate once (your browser opens for a Microsoft sign-in), then:

getdatareport takes an optional date (yyyy-MM-dd) and an optional ip (IPv4). A date is required to filter by IP, because the API path is /api/report/data/{date}/{ip}.

How authentication works

Shortened. The full README is on GitHub.