mail_manage_email_labels · Pyfastmail MCP: Risk & Policy

WHAT IT DOES

What mail_manage_email_labels does on Pyfastmail

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

WHY IT NEEDS A POLICY

Why mail_manage_email_labels needs a policy

Managing email labels (adding, removing, or organizing labels on emails) is a write operation that modifies email metadata. While reversible, it can significantly alter email organization and visibility. The empty description lowers confidence slightly, but the context of a mail management tool and 'manage' verb in the name clearly indicates a write action.

From the tool's definition Tool name 'mail_manage_email_labels' indicates modification of email labels/categories. The server description states it provides 'full access to Fastmail accounts for managing email' through JMAP protocol. Label management is a reversible write operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

mail_manage_email_labels Rate-limited

mail_manage_email_labels 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_manage_email_labels": {
      "limits": [
        {
          "counter": "mail_manage_email_labels_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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

FAQ

Questions about mail_manage_email_labels

What does the mail_manage_email_labels tool do? +

mail_manage_email_labels. It is categorised as a Write tool in the Pyfastmail 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_manage_email_labels? +

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

What risk level is mail_manage_email_labels? +

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

Can I rate-limit mail_manage_email_labels? +

Yes. Add a rate_limit block to the mail_manage_email_labels 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_manage_email_labels completely? +

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

mail_manage_email_labels is provided by the Pyfastmail MCP server (pjosols/pyfastmail-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.