mail_send · MCP Apple Mail MCP: Risk & Policy

WHAT IT DOES

What mail_send does on MCP Apple Mail

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

WHY IT NEEDS A POLICY

Why mail_send needs a policy

This tool creates new email messages and transmits them to external recipients, which is a reversible write operation. While emails cannot be easily unsent after delivery to recipients, the act itself is classified as Write rather than Destructive because the original data structures are not being deleted or overwritten.

From the tool's definition Tool name 'mail_send' and description 'Send an email from a specific account' indicate the tool creates and transmits new email messages, modifying the mail system state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

mail_send Rate-limited

mail_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": {
    "mail_send": {
      "limits": [
        {
          "counter": "mail_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 MCP Apple Mail, so you can run agents against it safely.

FAQ

Questions about mail_send

What does the mail_send tool do? +

Send an email from a specific account. It is categorised as a Write tool in the MCP Apple Mail MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on mail_send? +

Register the MCP Apple Mail MCP server in PolicyLayer and add a rule for mail_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 MCP Apple Mail. Nothing to install.

What risk level is mail_send? +

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

Can I rate-limit mail_send? +

Yes. Add a rate_limit block to the mail_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 mail_send completely? +

Set action: deny in the PolicyLayer policy for mail_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 mail_send? +

mail_send is provided by the MCP Apple Mail MCP server (lionsr/mcp-apple). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.