email_send · M365 MCP: Risk & Policy

WHAT IT DOES

What email_send does on M365

AI agents use email_send 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_send needs a policy

Sending emails is a write operation that creates and transmits data with potentially significant side effects (messages delivered to recipients). While not destructive or financial in isolation, misuse could cause spam, phishing, impersonation, or communication fraud.

From the tool's definition Tool name 'email_send' combined with server context describing 'Outlook' management and 'natural language commands' indicates this tool sends emails.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

email_send Rate-limited

email_send 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_send": {
      "limits": [
        {
          "counter": "email_send_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_send

What does the email_send tool do? +

email_send. 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_send? +

Register the M365 MCP server in PolicyLayer and add a rule for email_send: 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_send? +

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

Can I rate-limit email_send? +

Yes. Add a rate_limit block to the email_send 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_send completely? +

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

email_send 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.