set_forwarding · TrekMail MCP Server MCP: Risk & Policy

WHAT IT DOES

What set_forwarding does on TrekMail MCP Server

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

WHY IT NEEDS A POLICY

Why set_forwarding needs a policy

set_forwarding modifies email routing and forwarding configuration, making it a Write operation. While it affects message delivery and could redirect emails away from intended recipients if misconfigured, the changes are reversible (forwarding can be disabled/reconfigured).

From the tool's definition Tool enables configuration of email forwarding, which modifies mailbox settings and routing behavior ("Set targets, enable/disable forwarding"). This is a reversible change to email infrastructure state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_forwarding Rate-limited

set_forwarding 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": {
    "set_forwarding": {
      "limits": [
        {
          "counter": "set_forwarding_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 TrekMail MCP Server, so you can run agents against it safely.

FAQ

Questions about set_forwarding

What does the set_forwarding tool do? +

Configure email forwarding for a mailbox. Set targets, enable/disable forwarding, and choose whether to keep a copy in the original mailbox. It is categorised as a Write tool in the TrekMail MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_forwarding? +

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

What risk level is set_forwarding? +

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

Can I rate-limit set_forwarding? +

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

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

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