How to Auto-Categorize Support Emails with AI (n8n Tutorial)

How to Auto-Categorize Support Emails with AI (n8n Tutorial)

An n8n workflow fires on each new support email, asks Claude for the topic and urgency, then labels it in Gmail and pings Slack when it's urgent. You open an inbox that has already triaged itself: angry customer first, FAQ last.

Your angriest customer is buried

Support inboxes punish you for not reading everything. The one furious customer about to churn sits buried under ten password resets, and you find them an hour too late. This **n8n** workflow reads every incoming message for you, tags it by what it is and how urgent it is, and floats the ones that need you now to the top. You open an inbox that has already triaged itself.

Picture the assembly line

Before you build, picture the **assembly line**. An email arrives, AI reads it, it gets a label, and the urgent ones trip an alarm. Four moving parts do all the work: - **Trigger** fires the instant a support email lands. - **Claude** reads it and returns a category plus an urgency. - **Gmail** applies a matching label so the inbox sorts itself. - **Slack** pings you the moment something is urgent.

Start with the trigger

In n8n, add a **Gmail Trigger** watching your support inbox or a specific label. This is the workflow's heartbeat: every new message kicks off the assembly line automatically, day and night. Watching one app and reacting in another is exactly what n8n is built for, and it's why this is an Intermediate build rather than a quick chat prompt.

Make the AI answer in JSON

Add the **Anthropic (Claude)** node. The trick that makes everything downstream work is demanding **structured output**, plain JSON, so the next steps treat the answer as data instead of guessing meaning from a paragraph. Hand Claude your exact buckets and it sorts reliably. ``` Classify this support email. Return JSON only: { "category": one of ["billing","bug","feature_request","how_to","other"], "urgency": one of ["low","medium","high"], "summary": one short sentence } Email: From: {{ $json.from }} Subject: {{ $json.subject }} Body: {{ $json.text }} ```

Label it, alert on urgent

Add a **Gmail** node that applies a label matching `category`, so your inbox color-codes itself the moment mail arrives. Then add an **If** node: when `urgency` equals "high," a **Slack** node posts the summary and a link into your support channel. That furious customer now reaches you in seconds instead of hours, which is often the whole difference between a save and a churn.

Let it draft the reply too

Once you trust the labels, add a second **Claude** node that takes the email plus your **help-doc text** and writes a response, then a **Gmail** node set to *Create Draft*. You still read and send, so a human approves every word. Each reply now starts 90% written and on-brand instead of from a blank box, and that blank box is exactly where your time used to disappear.

Privacy is why you self-host

When you **self-host n8n**, the workflow runs on your own server. Customer email content only ever leaves it for the one AI API call you deliberately choose to make. For teams handling sensitive support, that control is the entire reason to run your own n8n instead of handing everything to a cloud tool you can't see inside.

Build the trigger, test one email

Spin up n8n, add the Gmail Trigger on your support inbox, and wire just the Claude classification node after it. Send yourself a test email and watch the JSON come back. Once that works, add the label and Slack steps, then flip the workflow to **Active** so your inbox triages itself around the clock.

Try this now

Your turn: open n8n and set up the first step. Just do step one now — the rest takes minutes. Save this guide to pick up where you left off.

FAQ