get_mailbox_stats

THE RISK

Low Risk

Why get_mailbox_stats needs a policy

This tool queries and returns mailbox statistics (unread count, total email count) without modifying data, executing code, or triggering side effects. It is a pure read operation that retrieves informational metadata about the user's mailbox state.

From the tool's definition Tool name 'get_mailbox_stats' and description 'Get statistics for a mailbox (unread count, total emails, etc.)' indicate retrieval of metadata only with no modification or execution of operations.

Documented attack patterns abuse exactly the kind of access get_mailbox_stats gives an agent:

POLICY

How to control get_mailbox_stats

PolicyLayer is an MCP gateway — it sits between your AI agents and Fastmail MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for get_mailbox_stats:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "get_mailbox_stats": {}
  }
}

get_mailbox_stats is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

Create a free account and register Fastmail MCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

CAP THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Fastmail MCP Server tools

Destructive bulk_delete Delete multiple emails (move to trash) Destructive delete_email Delete an email (move to trash) Write bulk_remove_labels Remove labels from multiple emails simultaneously Write remove_labels Remove specific labels (mailboxes) from an email Write reply_email Reply to an existing email with proper threading headers (In-Reply-To, References). Automa Write test_bulk_operations Test bulk operations by finding recent emails and performing safe operations (mark read/un Write add_labels Add labels (mailboxes) to an email without removing existing ones Write bulk_add_labels Add labels to multiple emails simultaneously

All 38 Fastmail MCP Server tools →

Read tools on other servers

M-Team MCP Server get_torrent_detail YouTube MCP Server search_channel Android Forensics ADB MCP Server parse_browser_history 0xarchive web3_challenge

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Data exfiltration → How read access becomes an exfiltration channel when chained with untrusted content.
MCP token cost → What connecting this server costs in context-window tokens on every request.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about get_mailbox_stats

What does the get_mailbox_stats tool do? +

Get statistics for a mailbox (unread count, total emails, etc.). It is categorised as a Read tool in the Fastmail MCP Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on get_mailbox_stats? +

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

What risk level is get_mailbox_stats? +

get_mailbox_stats is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit get_mailbox_stats? +

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

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

get_mailbox_stats is provided by the Fastmail MCP Server MCP server (madllama25/fastmail-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Fastmail MCP Server tool call.

Start from Fastmail MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →