Overview
An n8n workflow that automatically classifies incoming Gmail emails using Gemini AI, then takes action by archiving spam, logging summaries in Google Sheets, or generating AI-powered replies for sales/support emails. Reduced manual email handling by 70%.
The Problem
Businesses waste hours daily sorting emails, missing urgent support requests or sales leads. Manual replies are inconsistent, and critical emails often get buried in spam.
Technical Solution
System Architecture
- •n8n workflow with event-triggered Gmail API integration
- •Gemini AI nodes for 2-stage processing (classification → reply generation)
- •Google Sheets as a lightweight database for audit logs
- •Conditional logic for email routing (spam/support/sales/other)
Tools
n8n, Gemini 1.5 Pro
Triggers
Gmail push notifications
Processing Time
~9 sec/email
Data Storage
Google Sheets
Results & Impact
95%
Email categorization accuracy
8s
Avg. processing time per email
40%
Faster response to support/sales leads
Lessons Learned
Prompt Engineering Matters
Fine-tuned Gemini prompts reduced misclassifications from 12% to 5%.
n8n Limitations
Hit API rate limits with high email volumes, solved by adding delay nodes.
Sheets as a Database
Google Sheets sufficed for logging but would scale poorly beyond 10K emails/month.