email_forward · M365 MCP: Risk & Policy

WHAT IT DOES

What email_forward does on M365

AI agents use email_forward to create or update resources in M365 — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your M365 environment.

WHY IT NEEDS A POLICY

Why email_forward needs a policy

Email forwarding is a Write operation—it creates new message records and updates routing without permanently deleting or overwriting data. Severity is medium because forwarding could redirect sensitive communications to unintended recipients if an AI agent forwards messages without proper authorization or context.

From the tool's definition Tool name 'email_forward' indicates forwarding emails within Outlook/Microsoft 365. The server description confirms it manages Outlook services. Forwarding creates or modifies email records (new message record, routing metadata) reversibly.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

email_forward Rate-limited

email_forward 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": {
    "email_forward": {
      "limits": [
        {
          "counter": "email_forward_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches M365, so you can run agents against it safely.

FAQ

Questions about email_forward

What does the email_forward tool do? +

email_forward. It is categorised as a Write tool in the M365 MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on email_forward? +

Register the M365 MCP server in PolicyLayer and add a rule for email_forward: 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 M365. Nothing to install.

What risk level is email_forward? +

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

Can I rate-limit email_forward? +

Yes. Add a rate_limit block to the email_forward 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 email_forward completely? +

Set action: deny in the PolicyLayer policy for email_forward. 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 email_forward? +

email_forward is provided by the M365 MCP server (robin-collins/m365-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.