create_invite · TrekMail MCP Server MCP: Risk & Policy

WHAT IT DOES

What create_invite does on TrekMail MCP Server

AI agents use create_invite 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 create_invite needs a policy

This tool creates a new invite object and sends an email, both Write operations. The effects are reversible (the invite can be revoked, the mailbox setup incomplete). While it has side effects (email dispatch), it does not execute arbitrary code, delete data, move money, or trigger irreversible changes.

From the tool's definition Tool description states it 'Create[s] a setup invite for a mailbox' and 'Sends an email to the recipient' — these are create and send operations that modify state (mailbox setup, email dispatch) reversibly.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_invite Rate-limited

create_invite 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_invite": {
      "limits": [
        {
          "counter": "create_invite_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 create_invite

What does the create_invite tool do? +

Create a setup invite for a mailbox. Sends an email to the recipient with a link to set their own password and complete mailbox setup. Storage defaults to the shared account pool; pass storage_allocation_mb to pre-allocate dedicated storage that the recipient inherits at redeem. 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 create_invite? +

Register the TrekMail MCP Server MCP server in PolicyLayer and add a rule for create_invite: 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 create_invite? +

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

Can I rate-limit create_invite? +

Yes. Add a rate_limit block to the create_invite 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_invite completely? +

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

create_invite 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.