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Set-up documentation
Connect your mailbox to n8n
n8n's published documentation describes a field the shipping node no longer has. Which screen you get depends on your node version, so this page covers both.
Endpoint
The MCP Client Tool node
There is no configuration file here. n8n attaches an MCP server as a node in a workflow: add an MCP Client Tool and connect it to an AI Agent node, and the agent gains every tool the server offers.
That makes n8n different from every other client in this section in one practical way: the workflow runs without anybody watching it. Read the section on limiting the tool list below before you put this near a real mailbox.
What to put in it
| Field | Value |
|---|---|
| Endpoint | https://mcp.mailbox-mcp.com/db/mcp/YOUR-MAILBOX-KEY |
| Server Transport | HTTP Streamable. The other option is Server Sent Events, marked deprecated. |
| Authentication | Bearer Auth, with an access token from the control panel. |
| Tools to Include | Selected, in almost every case. See below. |
| Timeout | 60000 ms by default. Raise it if you search large mailboxes. |
Authentication has an MCP OAuth2 option, and it is not the URL-only sign-in the chat clients use: it is a stored n8n credential with a client id and secret in it, which this server does not issue. Bearer Auth with an access token is the route that works.
If your node looks different
n8n's published documentation for this node still describes a single field called SSE Endpoint and no transport picker at all. That is node version 1. If that is what you see, you are on an old node and it cannot reach this server.
| Node version | What you get |
|---|---|
| 1 | SSE Endpoint only. No transport picker, no authentication choice. Not usable here. |
| 1.1 | Endpoint appears. Still no transport picker. |
| 1.2 and later | Server Transport and Authentication both appear, defaulting to HTTP Streamable. |
A node already placed in a workflow keeps the version it was created with, so upgrading n8n does not upgrade the node. Delete it and add a fresh one. That table came from reading the node's own source rather than the documentation, which is why it can tell you something the documentation does not.
Limit what the workflow can reach
Set Tools to Include to Selected and pick the ones the workflow actually needs. This is the single most useful thing on this page.
An unattended agent with the full tool list can send, delete and move mail
on a judgement nobody reviewed. A workflow that files support mail into
folders needs to read, search and move, and nothing else; giving it
send_email as well buys nothing and costs you the one
afternoon where the model decides a reply would be helpful.
Read tools still cost calls
Every tool call counts against the mailbox's daily limit, including the read-only ones, and a workflow on a schedule spends them far faster than a person does. Pricing states the ceiling.
Check that it worked
Execute the workflow manually once before scheduling it. The node reports what it fetched, so a wrong endpoint or a rejected token shows up on the first run rather than at three in the morning.
A first workflow worth building
Every hour, read anything unread in the support inbox, and post a one-line summary of each to a channel.
Read-only, so nothing can go wrong in the mailbox, and it leaves every message unread for whoever normally works it, because reading through this server never sets the seen flag. That is the difference between a summary bot and one that quietly empties your unread list.
The free tier is 5 MCP calls a day, which a scheduled workflow will use before lunch. Worth knowing before you build against it.
Where to go next
The tool reference is the page to have open while you fill in Tools to Include: it names every tool and marks which ones only read. Pricing states the daily ceiling an automation runs into first.
- Which n8n releases shipped node versions 1.1, 1.2 and 1.4. The node versions come from the source; the mapping to releases does not.
Read 30 August 2026 Every value on this page came off n8n documentation: MCP Client Tool on that day. The published page still documents the SSE Endpoint field, which only node version 1 has. If it has changed since, tell us and we will read it again.