pop3_check

Check POP3 server connectivity. Reads server greeting and tests STARTTLS capability for port 110; uses implicit TLS for port 995. Does not authenticate.

SERVERMcp Nettools SOURCEaaronckj/mcp-nettools

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/aaronckj-mcp-nettools/pop3-check.md

WHAT IT DOES

What pop3_check does on Mcp Nettools

AI agents call pop3_check to retrieve information from Mcp Nettools without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why pop3_check is rated Low

This tool performs network diagnostics (consistent with server purpose) to verify POP3 server availability and TLS support. It reads responses from a remote server without modifying state, executing code, deleting data, or moving money. The lack of authentication means it cannot access mailbox contents.

From the tool's definition Tool checks POP3 server connectivity by reading server greeting and testing STARTTLS capability without authentication. The description explicitly states 'reads server greeting' and 'does not authenticate', indicating it performs passive reconnaissance only.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs pop3_check safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Mcp Nettools, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For pop3_check, this is the rule to start with:

pop3_check Allowed

pop3_check is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "pop3_check": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Mcp Nettools, apply this rule, and every pop3_check call is checked against it from then on.

FAQ

Questions about pop3_check

What does the pop3_check tool do? +

Check POP3 server connectivity. Reads server greeting and tests STARTTLS capability for port 110; uses implicit TLS for port 995. Does not authenticate. It is categorised as a Read tool in the Mcp Nettools MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on pop3_check? +

Register the Mcp Nettools MCP server in PolicyLayer and add a rule for pop3_check: 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 Nettools. Nothing to install.

What risk level is pop3_check? +

pop3_check is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit pop3_check? +

Yes. Add a rate_limit block to the pop3_check 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 pop3_check completely? +

Set action: deny in the PolicyLayer policy for pop3_check. 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 pop3_check? +

pop3_check is provided by the Mcp Nettools MCP server (aaronckj/mcp-nettools). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

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