n8n Gmail AI Classifier: Log Enquiries to Google Sheets

Turn every real Gmail enquiry into a clean, structured Google Sheets log—automatically

This n8n workflow polls your Gmail inbox, filters out auto-replies and bounce emails, then uses an OpenAI-compatible Chat Completions model to classify genuine enquiries and append them as validated rows in Google Sheets.

What this workflow does

• Polls Gmail every 15 minutes and fetches emails regardless of read status.
• Filters and normalizes incoming messages by removing common machine-generated emails (e.g., out-of-office replies and delivery failures) and standardizing key fields such as sender, reply-to, subject, body, and a short excerpt.
• Classifies enquiries with OpenAI-compatible chat by sending the email content to the OpenAI Chat Completions API to generate a JSON output.
• Validates, sanitizes, and hardens the AI result against allowed values, escalates to high priority when required, substitutes missing or out-of-range fields, and sanitizes text to prevent Google Sheets formula injection.
• Appends one structured row per enquiry into Google Sheets with received time, sender details, the AI classification (category, priority, sentiment, language, summary, recommended action), and the excerpt.

Use cases

• Support and sales teams who want automatic lead/enquiry logging directly from Gmail into Google Sheets.
• SaaS operators tracking incoming requests and prioritizing tickets without manual triage.
• Automation engineers building an AI-assisted email intake pipeline using n8n, Gmail, OpenAI-compatible models, and Google Sheets.

Technical details

• n8n Gmail Trigger (polling interval + search query settings)
• HTTP Request to OpenAI-compatible Chat Completions API
• Code + Set steps for formatting, validation, and escalation logic
• Google Sheets integration to append structured rows (with formula injection protection)

Perfect for n8n automation workflow builders who need reliable, structured enquiry classification from Gmail.