List emails from one or all accounts. Reads the local SQLite cache when warm (~165ms); pass live=true to hit IMAP. Pass with_preview to also fetch a body snippet of N chars per email in the same round-trip — saves an email_show call per result. Unread is reported as three distinct fields: unread_...
AI agents call email_list 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_list performs querying and data retrieval operations without any side effects. It reads from cache or IMAP, returns email metadata and optional body previews, and reports unread status counters. No data is created, modified, deleted, or executed.
From the tool's definition Tool description states 'List emails from one or all accounts. Reads the local SQLite cache' and 'fetch a body snippet' — purely retrievals with no modification, deletion, or execution.
Documented attack patterns abuse exactly the kind of access email_list 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_list:
{
"version": "1",
"default": "deny",
"tools": {
"email_list": {}
}
}email_list is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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List emails from one or all accounts. Reads the local SQLite cache when warm (~165ms); pass live=true to hit IMAP. Pass with_preview to also fetch a body snippet of N chars per email in the same round-trip — saves an email_show call per result. Unread is reported as three distinct fields: unread_in_result (unread among returned rows — always trustworthy), folder_unread (server count for this folder), and account_unread_total (null unless include_account_unread=true). unread_as_of marks snapshot freshness. 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_list: 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_list 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_list 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_list. 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_list 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.