set-email-categories · Outlook MCP Server MCP: Risk & Policy

WHAT IT DOES

What set-email-categories does on Outlook MCP Server

AI agents use set-email-categories to create or update resources in Outlook MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Outlook MCP Server environment.

WHY IT NEEDS A POLICY

Why set-email-categories needs a policy

This tool modifies email metadata in a reversible manner by updating categories/labels. It does not delete data (Destructive), execute arbitrary operations (Execute), involve financial transactions (Financial), or retrieve data without side effects (Read).

From the tool's definition Tool description states it 'Sets categories (color-coded labels) on a specific email' and 'replaces all existing categories on the email with the provided list.' This is a metadata modification operation that does not create, delete, or send emails—it only…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set-email-categories Rate-limited

set-email-categories stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "set-email-categories": {
      "limits": [
        {
          "counter": "set-email-categories_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Outlook MCP Server, so you can run agents against it safely.

FAQ

Questions about set-email-categories

What does the set-email-categories tool do? +

Sets categories (color-coded labels) on a specific email. This replaces all existing categories on the email with the provided list. Categories must exist in your mailbox (use get-master-categories to see available options). It is categorised as a Write tool in the Outlook MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set-email-categories? +

Register the Outlook MCP Server MCP server in PolicyLayer and add a rule for set-email-categories: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Outlook MCP Server. Nothing to install.

What risk level is set-email-categories? +

set-email-categories is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit set-email-categories? +

Yes. Add a rate_limit block to the set-email-categories rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block set-email-categories completely? +

Set action: deny in the PolicyLayer policy for set-email-categories. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides set-email-categories? +

set-email-categories is provided by the Outlook MCP Server MCP server (peacockery-studio/outlook-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.