n8n Gmail Portal Enquiry Auto-Reply w/ OpenAI + Sheets

Instant, accurate first replies to portal enquiries—automatically drafted in Gmail (with AI, but never unchecked)

This n8n workflow watches your Gmail for new Rightmove, Zoopla, OnTheMarket, or website enquiry emails, extracts the key details using OpenAI, and creates a Gmail draft reply for a quick human review—logging every lead to Google Sheets with retention controls. Nothing is sent automatically, so you stay in control.

What this workflow does

• Monitors a Gmail label: watches for new emails in the label portal-leads (set up via a Gmail filter).
• Sends enquiry text to OpenAI with a strict SYSTEM prompt to extract: name, contact details, property, position, finance and timeline, then write a short, personal first reply with up to three qualifying questions.
• Validates the AI output using a Code step: the reply address must appear in the original email, must not be your own address or a portal’s domain, and the AI must not add links or contact details. The prompt treats the enquiry text as data, never instructions.
• Logs the lead in Google Sheets (tab Leads) and applies a delete-after date for data retention.
• Saves a Gmail draft for the person to review and send—using your booking link, signature, and privacy notice from the Settings node. No automatic sending.

Use cases

• UK letting/estate agents needing a faster first response to portal enquiries without risking unchecked outbound messages.
• Automation engineers deploying an AI-assisted Gmail portal enquiry auto-reply with validation and audit logging.
• SaaS operators using n8n to standardise lead capture from email forms into Sheets + draft replies.

Technical details

• n8n nodes/steps used include: if, set, code, gmail, sticky note, and http request.
• Integrations: Gmail, OpenAI, and Google Sheets (add your own credentials in your n8n instance).
• Customization: edit SYSTEM_PROMPT (tone/questions) and choose AI_MODEL.

Made by Burnt & To.