Fetch the body of one or more emails over a single IMAP connection. Each id can be a bare UID + account_id, or a global gid
AI agents call email_show to retrieve information from MCP Email Service without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
email_show performs data retrieval only (fetching email body content) with no side effects, modification, deletion, or execution capabilities. This is a classic Read operation. The tool has low severity because unauthorized email reading, while a privacy concern, does not have the blast radius of destructive, financial, or code execution risks.
From the tool's definition Tool description states it 'Fetch[es] the body of one or more emails', which is a retrieval operation with no modification or deletion. The verb 'fetch' and the function of retrieving email content are read-only operations.
Documented attack patterns abuse exactly the kind of access email_show gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and MCP Email Service, and nothing reaches the server without passing your rules. This is the rule we recommend for email_show:
{
"version": "1",
"default": "deny",
"tools": {
"email_show": {}
}
}email_show is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Fetch the body of one or more emails over a single IMAP connection. Each id can be a bare UID + account_id, or a global gid. It is categorised as a Read tool in the MCP Email Service MCP Server, which means it retrieves data without modifying state.
Register the MCP Email Service MCP server in PolicyLayer and add a rule for email_show: 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 Email Service. Nothing to install.
email_show 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 email_show 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 email_show. 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.
email_show is provided by the MCP Email Service MCP server (leeguooooo/mailbox). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from MCP Email Service, 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.
16 MCP Email Service tools catalogued and risk-classified — across an index of 43,000+ MCP servers.