update-sandbox-inbox · Mcp Mailtrap MCP: Risk & Policy

WHAT IT DOES

What update-sandbox-inbox does on Mcp Mailtrap

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

WHY IT NEEDS A POLICY

Why update-sandbox-inbox needs a policy

This tool modifies inbox metadata (name or email username) reversibly without deleting data or executing external code. It qualifies as Write rather than Read (retrieves data only) or Execute (runs code). Severity is medium because misconfiguration could disrupt email testing workflows, but the change is reversible and limited in scope to sandbox infrastructure.

From the tool's definition Tool explicitly performs "Update a sandbox inbox name or email username" — modifying existing inbox configuration data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update-sandbox-inbox Rate-limited

update-sandbox-inbox 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": {
    "update-sandbox-inbox": {
      "limits": [
        {
          "counter": "update-sandbox-inbox_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 Mailtrap, so you can run agents against it safely.

FAQ

Questions about update-sandbox-inbox

What does the update-sandbox-inbox tool do? +

Update a sandbox inbox name or email username. It is categorised as a Write tool in the Mcp Mailtrap MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update-sandbox-inbox? +

Register the Mcp Mailtrap MCP server in PolicyLayer and add a rule for update-sandbox-inbox: 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 Mailtrap. Nothing to install.

What risk level is update-sandbox-inbox? +

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

Can I rate-limit update-sandbox-inbox? +

Yes. Add a rate_limit block to the update-sandbox-inbox 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 update-sandbox-inbox completely? +

Set action: deny in the PolicyLayer policy for update-sandbox-inbox. 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 update-sandbox-inbox? +

update-sandbox-inbox is provided by the Mcp Mailtrap MCP server (mcp-mailtrap). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.