Get list of mailboxes/folders with their IDs, names, and metadata. Call this first to get mailbox IDs needed for search_emails (inMailbox filter) and move_emails (mailboxId). Common mailbox names: Inbox, Drafts, Sent, Trash, Archive, Spam/Junk. Results are paginated - use position parameter for p...
AI agents call get_mailboxes to retrieve information from JMAP 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 lists email mailbox information. It has no capability to modify, delete, execute code, or perform any action with side effects. It is a pure query operation used to enumerate available mailboxes, making it a Read category tool with low severity.
From the tool's definition Tool description states it 'Get list of mailboxes/folders' - a retrieval operation with no side effects. The description explicitly mentions it provides 'IDs, names, and metadata' for use by other tools, indicating it is purely informational and read-only.
Documented attack patterns abuse exactly the kind of access get_mailboxes gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and JMAP MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for get_mailboxes:
{
"version": "1",
"default": "deny",
"tools": {
"get_mailboxes": {}
}
}get_mailboxes is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Get list of mailboxes/folders with their IDs, names, and metadata. Call this first to get mailbox IDs needed for search_emails (inMailbox filter) and move_emails (mailboxId). Common mailbox names: Inbox, Drafts, Sent, Trash, Archive, Spam/Junk. Results are paginated - use position parameter for pagination. It is categorised as a Read tool in the JMAP MCP MCP Server, which means it retrieves data without modifying state.
Register the JMAP MCP server in PolicyLayer and add a rule for get_mailboxes: 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 JMAP MCP. Nothing to install.
get_mailboxes 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 get_mailboxes 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 get_mailboxes. 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.
get_mailboxes is provided by the JMAP MCP server (wyattjoh/jmap-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 11 JMAP MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
11 JMAP MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.