Gmail Trigger: Auto-Draft Replies with OpenAI (n8n)

Turn new Gmail emails into polished reply drafts—automatically with OpenAI

This n8n workflow watches your Gmail inbox for incoming messages, generates a reply using OpenAI in your preferred tone, and saves it as a draft in the original email thread—so you stay in control while speeding up response time.

What this workflow does

• Monitors your inbox every minute for new emails that match your Gmail search filter (default behavior excludes Promotions and Social categories).
• Extracts key email details—the sender, subject, and email body—from the incoming message.
• Uses OpenAI to draft a reply by sending your instructions (name, sign-off, tone, and rules) along with the email content to generate a response body.
• Creates a Gmail draft reply addressed to the original sender and attached to the same thread with a “Re:” subject line.

Use cases

• SaaS support triage: Draft replies for common incoming customer questions while you review before sending.
• Sales follow-ups: Generate courteous, on-brand responses to inbound leads without manual typing.
• Founder/operator communications: Keep your inbox moving with consistent tone and sign-off across conversations.
• Automation engineers: Use it as a practical template for Gmail → OpenAI → Gmail draft workflows in n8n.

Technical details

• n8n Gmail trigger: Runs on a schedule (every minute) and filters messages using your Gmail q query.
• OpenAI integration: Uses the n8n OpenAI node (n8nn8n-nodes-langchainopen ai) to generate the reply text.
• Gmail draft action: Writes the generated response as a draft in the existing thread.
• Credentials required: Gmail OAuth for both the trigger and draft action; OpenAI credentials with a model available in your OpenAI account.
• Prompt configuration: Update the OpenAI system prompt with your name, sign-off, tone, and any standing rules.

Bring AI-assisted Gmail responses into your workflow—automatically draft replies, then review and send when ready.