Automatically Label Gmail Emails with GPT-5 Classification

Description

How it works
This workflow automatically monitors your Gmail inbox and uses OpenAI's GPT model to intelligently classify incoming emails into four key categories:
High Priority - Urgent emails requiring immediate attention from executives, clients, or stakeholders
Promotion - Marketing emails, sales offers, product launches, and event invitations
Finance/Billing - Invoices, receipts, payment notifications, and financial records
Customer Support - Help requests, troubleshooting queries, and service-related issues

Once classified, emails are automatically labeled in Gmail using the appropriate tags, making it easy to filter, search, and prioritize your communications.

How to set up
Requirements
Gmail account with OAuth2 access enabled
OpenAI API key with GPT model access
Custom Gmail labels created for each category

Step-by-step setup
Create Gmail Labels
In Gmail, create these labels: "High Priority", "Promotion", "Finance/Billing", "Customer Support"
Note the label IDs (you'll need to replace the hardcoded ones in the workflow)
Configure Credentials
Add your Gmail OAuth2 credentials in n8n
Add your OpenAI API credentials
Update Label IDs
Replace the hardcoded label IDs in each Gmail node with your actual label IDs
You can find label IDs by testing the Gmail node or using Gmail API
Adjust Classification Rules
Review the Text Classifier categories and modify descriptions to match your specific needs
Add or remove categories as required
Set Polling Frequency
The workflow is set to check every minute - adjust based on your email volume