List all domains from Resend. Returns domain names, statuses, regions, and capabilities. Don
AI agents call list-domains to retrieve information from Email Sending MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and queries existing domain configuration data without creating, modifying, deleting, or executing operations. It is a simple informational lookup that poses minimal risk if accessed by an AI agent, as it only exposes metadata about domains already configured in the user's Resend account.
From the tool's definition Tool description states 'List all domains from Resend. Returns domain names, statuses, regions, and capabilities.' The verb 'List' and return of read-only domain information indicates pure data retrieval with no side effects or modifications.
Documented attack patterns abuse exactly the kind of access list-domains gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Email Sending MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for list-domains:
{
"version": "1",
"default": "deny",
"tools": {
"list-domains": {}
}
}list-domains is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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List all domains from Resend. Returns domain names, statuses, regions, and capabilities. Don. It is categorised as a Read tool in the Email Sending MCP MCP Server, which means it retrieves data without modifying state.
Register the Email Sending MCP server in PolicyLayer and add a rule for list-domains: 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 Email Sending MCP. Nothing to install.
list-domains is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the list-domains 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 list-domains. 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.
list-domains is provided by the Email Sending MCP server (resend/resend-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 77 Email Sending MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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77 Email Sending MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.