LABSCO SUMMARY

The hard part of agent email is oversight, and that is what this is.

Sending mail was never the problem — handing an agent an outbox was. Here the mailbox ships with the gate already on: it reads and drafts freely, a person approves what leaves, and the leash lengthens one rung at a time as you decide it has earned it.

What it is

A mailbox built for agents rather than a bridge into yours. Every mailbox runs in one of five oversight modes, from read-only to fully autonomous, and in the default mode inbound arrives immediately while outbound waits for a human to approve it.

What you get

An email address the agent owns, with cryptographic identity on every message it sends
Five oversight modes — read_only, gated_all, gated_send, monitored, autonomous — with gated_send the default
A per-recipient allowlist, exact addresses or domain wildcards, that skips the approval queue
Allowlist additions that require operator email approval, so the agent cannot self-approve one
Upgrades requested by the agent and approved with a one-time code; downgrades need no approval, and the agent can always restrict itself
A gated approval path with a published Lean 4 proof that no email reaches delivery without passing it

Requirements

Nothing to install on the hosted path — point a client at https://mcp.multimail.dev/mcp and authorise over OAuth on first connect. The local alternative runs under npx and takes an API key and the id of the mailbox it should attach to.

Setup effort

Paste a URL — add the endpoint to your client

See installation options

USE CASES

01

Letting an agent read your mail without letting it write

Start the mailbox read-only: it can triage, summarise and answer questions about what arrived, and sends are blocked at the mailbox rather than by a prompt.

check_inboxread_emailget_threaddownload_attachmentconfigure_mailboxupdate_mailbox

02

Approving what goes out

In the default mode inbound is delivered immediately while outbound sits in a queue you clear, so drafting is autonomous and sending is not.

list_pendingdecide_email

03

Cutting the approval load for routine correspondence

Allowlist the addresses or domains you already deal with, so the familiar threads go straight out and only new recipients reach you.

list_allowlistadd_allowlist_entryremove_allowlist_entry

04

Widening the leash as it earns it

The agent asks for a higher oversight mode and you approve with a one-time code — moving it back down needs no approval at all.

manage_upgradeupdate_mailbox

50 tools

Listed in project docs. Your client may show a different list.

send_email

check_inbox

read_email

reply_email

get_thread

download_attachment

cancel_message

edit_scheduled_email

wait_for_email

get_tags

set_tags

delete_tag

list_pending

decide_email

manage_upgrade

BEFORE YOU INSTALL

What to know first

Tools you get

50 tools named in the project's documentation.

Requires

A client that can reach a remote MCP server over HTTP

Where it runs

Of the 5 documented clients, 1 runs the server on your machine and 4 connect to a hosted endpoint.

INSTALLATION

Connect your client

Add the endpoint to your client.

Server setup

ENDPOINT URL

https://mcp.multimail.dev/mcp

MCP Clients

Claude Code

CLAUDE CODE · JSON

{
  "mcpServers": {
    "multimail": {
      "type": "http",
      "url": "https://mcp.multimail.dev/mcp"
    }
  }
}

Cursor

CURSOR · JSON

{
  "mcpServers": {
    "multimail": {
      "url": "https://mcp.multimail.dev/mcp"
    }
  }
}

Windsurf

WINDSURF · JSON

{
  "mcpServers": {
    "multimail": {
      "serverUrl": "https://mcp.multimail.dev/mcp"
    }
  }
}

VS Code — GitHub Copilot

VS CODE — GITHUB COPILOT · JSON

{
  "servers": {
    "multimail": {
      "type": "http",
      "url": "https://mcp.multimail.dev/mcp"
    }
  }
}

Any MCP client — local stdio

ANY MCP CLIENT — LOCAL STDIO · JSON

{
  "mcpServers": {
    "multimail": {
      "command": "npx",
      "args": [
        "-y",
        "@multimail/mcp-server"
      ],
      "env": {
        "MULTIMAIL_API_KEY": "<YOUR_MULTIMAIL_API_KEY>",
        "MULTIMAIL_MAILBOX_ID": "01KJ1NHN8J..."
      }
    }
  }
}

MultiMail