Enable greylisting for all domains (delays first-time senders to block spam)
AI agents use enable_greylisting to create or update resources in cPanel MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your cPanel MCP Server environment.
Enabling greylisting modifies email security settings globally across all domains by implementing a temporary rejection mechanism for unknown senders. While reversible (can be disabled), this is a Write action because it changes server configuration state.
From the tool's definition Tool name 'enable_greylisting' and description 'Enable greylisting for all domains' indicate a configuration change that modifies email handling behavior across all domains. This is a reversible write operation that alters system state.
Documented attack patterns abuse exactly the kind of access enable_greylisting gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and cPanel MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for enable_greylisting:
{
"version": "1",
"default": "deny",
"tools": {
"enable_greylisting": {
"limits": [
{
"counter": "enable_greylisting_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
} enable_greylisting 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.
Free to start. No card required.
Enable greylisting for all domains (delays first-time senders to block spam). It is categorised as a Write tool in the cPanel MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the cPanel MCP Server MCP server in PolicyLayer and add a rule for enable_greylisting: 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 cPanel MCP Server. Nothing to install.
enable_greylisting is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the enable_greylisting 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.
Set action: deny in the PolicyLayer policy for enable_greylisting. 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.
enable_greylisting is provided by the cPanel MCP Server MCP server (0xhayd3n/cpanel-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from cPanel MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
164 cPanel MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.