send-mail · Outlook OAuth MCP Server MCP: Risk & Policy

WHAT IT DOES

What send-mail does on Outlook OAuth MCP Server

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

WHY IT NEEDS A POLICY

Why send-mail needs a policy

Sending emails is a write operation that creates new data (outbound messages) and has side effects on the recipient and sender's mail systems. It is not destructive (emails can be recalled/deleted) nor financial in nature by itself.

From the tool's definition Tool name 'send-mail' and description 'Send an email message immediately' indicate the tool creates and transmits a new email message. This is a write operation that modifies the mailbox state by adding a sent message.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

send-mail Rate-limited

send-mail 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": {
    "send-mail": {
      "limits": [
        {
          "counter": "send-mail_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 Outlook OAuth MCP Server, so you can run agents against it safely.

FAQ

Questions about send-mail

What does the send-mail tool do? +

Send an email message immediately. It is categorised as a Write tool in the Outlook OAuth 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 send-mail? +

Register the Outlook OAuth MCP Server MCP server in PolicyLayer and add a rule for send-mail: 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 OAuth MCP Server. Nothing to install.

What risk level is send-mail? +

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

Can I rate-limit send-mail? +

Yes. Add a rate_limit block to the send-mail 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 send-mail completely? +

Set action: deny in the PolicyLayer policy for send-mail. 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 send-mail? +

send-mail is provided by the Outlook OAuth MCP Server MCP server (leonine-studios/useful-outlook-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.