test_smtp · TrekMail MCP Server MCP: Risk & Policy

WHAT IT DOES

What test_smtp does on TrekMail MCP Server

AI agents invoke test_smtp to trigger actions in TrekMail MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why test_smtp needs a policy

This tool executes an outbound SMTP connection test against an external server, which is an active network operation with side effects (connection attempts, authentication handshakes). It doesn't merely read data locally; it triggers an external operation. Severity is medium because misuse could leak credentials or be used to probe/enumerate SMTP servers, but it doesn't directly modify or destroy data.

From the tool's definition 'Test an SMTP connection with the provided credentials' — actively initiates a network connection to an external SMTP server using supplied credentials

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

test_smtp Rate-limited

test_smtp stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "test_smtp": {
      "limits": [
        {
          "counter": "test_smtp_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-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 test_smtp

What does the test_smtp tool do? +

Test an SMTP connection with the provided credentials. Returns a job_id to poll for results. It is categorised as a Execute tool in the TrekMail MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on test_smtp? +

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

test_smtp is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit test_smtp? +

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

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

test_smtp 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.