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

WHAT IT DOES

What create-sandbox-inbox does on Mcp Mailtrap

AI agents use create-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 create-sandbox-inbox needs a policy

This tool creates new sandbox inboxes and provisioning credentials, which is a write operation that modifies the state of the Mailtrap project. While sandbox inboxes are typically non-destructive test environments, the creation of new infrastructure and issuance of SMTP credentials represents data creation with side effects.

From the tool's definition Tool 'create-sandbox-inbox' creates a new resource (sandbox test inbox) and returns credentials, indicating irreversible creation of infrastructure within a project.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create-sandbox-inbox Rate-limited

create-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": {
    "create-sandbox-inbox": {
      "limits": [
        {
          "counter": "create-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 create-sandbox-inbox

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

Create a new sandbox test inbox within a project. Returns SMTP credentials for the new inbox. 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 create-sandbox-inbox? +

Register the Mcp Mailtrap MCP server in PolicyLayer and add a rule for create-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 create-sandbox-inbox? +

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

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

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

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

create-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.