star_email · ProtonMail MCP Server MCP: Risk & Policy

WHAT IT DOES

What star_email does on ProtonMail MCP Server

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

WHY IT NEEDS A POLICY

Why star_email needs a policy

Starring/unstarring is a metadata modification that creates or updates email flags without altering content or causing irreversible changes. This is a classic Write operation. Severity is low because the action affects only email organization flags, has minimal blast radius, and is fully reversible. The confidence is high because the intent is unambiguous.

From the tool's definition Tool name 'star_email' with description 'Star or unstar an email' indicates a reversible modification of email metadata (star status).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

star_email Rate-limited

star_email 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": {
    "star_email": {
      "limits": [
        {
          "counter": "star_email_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 ProtonMail MCP Server, so you can run agents against it safely.

FAQ

Questions about star_email

What does the star_email tool do? +

Star or unstar an email. It is categorised as a Write tool in the ProtonMail 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 star_email? +

Register the ProtonMail MCP Server MCP server in PolicyLayer and add a rule for star_email: 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 ProtonMail MCP Server. Nothing to install.

What risk level is star_email? +

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

Can I rate-limit star_email? +

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

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

star_email is provided by the ProtonMail MCP Server MCP server (ronamosa/protonmail-pro-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.