Smart Gmail auto-labeler with Gemini AI & sender history

n8n Gmail AI Auto-Labeler

> An intelligent n8n workflow that automatically classifies and labels Gmail emails using Google Gemini AI, keeping your inbox organized with zero manual effort.

This workflow uses AI-powered classification to analyze email content, learn from sender patterns, and automatically apply appropriate labels while archiving processed emails.

How It Works

Trigger: The workflow runs automatically every minute to check for new unread emails (or manually for bulk processing). Check for Existing Labels: Before processing, it verifies if the email already has an AI-assigned label to avoid duplicate processing. AI Classification: If unlabeled, the AI agent analyzes the email using: Sender History Tool - Fetches up to 10 previous emails from the same sender to identify patterns 80% Majority Rule - If 80%+ of sender's past emails have the same label, strongly prefers that category Label Examples Tool - When uncertain, compares the email with existing examples from suspected categories Smart Decision: The AI returns a structured JSON response: { "label": "Category Name" } Or "None" if no category fits. Apply & Archive: Label Applied → The workflow adds the appropriate Gmail label to the thread. Auto-Archive → Removes the email from INBOX (archives it) to maintain zero-inbox. Loop: Processes the next email in the batch, ensuring all new emails are classified.

Requirements

Gmail OAuth2 Credentials** - Connected Gmail account with API access. Google Gemini API Key** - Get it here Free tier: 15 requests/minute Gmail Labels** - Must be created in Gmail exactly as listed: Meetings Income Inquiries Notify / Verify Expenses Orders / Deliveries Trash Likely

How to Use

Import the Workflow: Copy the provided JSON file. In your n8n instance → click Import Workflow → select the JSON file.

Create Gmail Labels: Open Gmail → Settings → Labels → Create new labels. Use the exact names listed above (case-sensitive).

Get Your Label IDs: In the workflow, click "When clicking 'Execute workflow'" manual trigger. Execute the "Get Labels Info" node only. Copy each label's ID (format: Label_1234567890123456789).

Update Code Nodes with Your Label IDs:

Node 1: "Check Label Existence" const labelMap = { "Label_YOUR_ID_HERE": "Meetings", "Label_YOUR_ID_HERE": "Inquiries", "Label_YOUR_ID_HERE": "Notify / Verify", "Label_YOUR_ID_HERE": "Expenses", "Label_YOUR_ID_HERE": "Orders / Deliveries", "Label_YOUR_ID_HERE": "Trash Likely" };

Node 2: "Convert Label to Label ID" const labelToId = { "Meetings": "Label_YOUR_ID_HERE", "Inquiries": "Label_YOUR_ID_HERE", "Notify / Verify": "Label_YOUR_ID_HERE", "Expenses": "Label_YOUR_ID_HERE", "Orders / Deliveries": "Label_YOUR_ID_HERE", "Trash Likely": "Label_YOUR_ID_HERE" };

Set Up Credentials: Gmail OAuth2 → Authorize your Gmail account in n8n. Google Gemini API → Add your API key in n8n credentials.

Test the Workflow: Send yourself test emails with clear content (e.g., invoice, meeting invite). Use the manual trigger to process them. Verify labels are applied correctly.

Activate for Auto Mode: Toggle the workflow to Active. New unread emails will be processed automatically every minute.

Notes

Dual Execution Modes**: Auto Mode - Gmail Trigger polls inbox every minute for unread emails (real-time processing). Manual Mode - Use the manual trigger to bulk process existing emails (adjust limit in "Get many messages" node).

AI Learning from Patterns**: The workflow applies an 80% majority rule - if 80% or more of a sender's historical emails share the same label, the AI strongly prefers that category for new emails from that sender. This creates intelligent sender-based routing over time.

Skip Already Labeled Emails**: The "Check Label Existence" node prevents re-processing emails that already have an AI-assigned label. Ensures efficient execution and avoids duplicate work.

Structured AI Output**: Uses a Structured Output Parser to ensure the AI always returns valid JSON: { "label": "Category" }. If uncertain, returns { "label": "None" } and the email stays in inbox.

Background Archiving**: After labeling, emails are automatically removed from INBOX (archived). Maintains a zero-inbox workflow while preserving emails under their labels.

Rate Limits**: Google Gemini free tier: 15 requests/minute. Adjust polling frequency if hitting limits.

Example Behavior

Minute 1**: New invoice email arrives → AI fetches sender history → 85% were labeled "Expenses" → applies "Expenses" label → archives email. Minute 2**: Meeting invite arrives → No sender history → AI analyzes content (Zoom link, time) → applies "Meetings" label → archives email. Minute 3**: Promotional email arrives → AI compares with "Trash Likely" examples → applies label → archives email. Minute 4**: Already-labeled email detected → skipped silently.

Label Categories

| Label | Description | |-------|-------------| | Meetings | Calendar invites, Zoom/Meet links, appointments, scheduled events | | Expenses | Bills, invoices, receipts, payment reminders, subscription renewals | | Income | Payments received, payouts, deposits, earnings notifications | | Notify / Verify | Verification codes, login alerts, 2FA codes, account notifications | | Orders / Deliveries | Order confirmations, shipping updates, tracking numbers, deliveries | | Inquiries | Business outreach, sales proposals, partnerships, cold emails | | Trash Likely | Spam, newsletters, promotions, marketing blasts, ads |

> If no category fits clearly, the email returns "None" and remains in the inbox.

Customization

Change Polling Frequency**: Edit the "Gmail Trigger" node → pollTimes → mode (e.g., every5Minutes). Adjust Email Limit**: Modify limit: 10 in "Get many messages" node for manual bulk processing. Add Custom Labels**: Create in Gmail → Get ID → Update both Code nodes + AI system prompt. Modify 80% Rule**: Edit the AI agent's system message to adjust the majority threshold. Increase Tool Limits**: Change limit: 10 in Gmail tool nodes to fetch more historical data.

Author: Muhammad Anas Farooq