archive_messages · Mail MCP: Risk & Policy

WHAT IT DOES

What archive_messages does on Mail

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

WHY IT NEEDS A POLICY

Why archive_messages needs a policy

Archiving messages modifies email organization by moving them to a designated folder. This is a Write operation because it reversibly changes data state without destroying it—the messages remain accessible in the Archive folder and can be moved elsewhere or restored. Severity is medium because misuse could obscure important messages from the inbox (affecting visibility/workflow) but causes no data loss.

From the tool's definition Tool 'archive_messages' moves messages to the Archive folder, which is a reversible modification of message state/location.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

archive_messages Rate-limited

archive_messages 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": {
    "archive_messages": {
      "limits": [
        {
          "counter": "archive_messages_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 Mail, so you can run agents against it safely.

FAQ

Questions about archive_messages

What does the archive_messages tool do? +

Archive messages — moves them to the Archive folder. It is categorised as a Write tool in the 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 archive_messages? +

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

What risk level is archive_messages? +

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

Can I rate-limit archive_messages? +

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

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

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