Gmail Auto Reply Drafts with OpenAI (n8n Workflow Automation)

Instant Gmail Auto-Reply Drafts—Powered by OpenAI (with n8n)

This n8n workflow watches your Gmail inbox for new emails, uses OpenAI to determine whether you should reply, and automatically creates a plain-text Gmail draft reply in the same thread—so you can review and send it in seconds.

What this workflow does

• Polls Gmail every minute using a configurable Gmail search query to find new messages you want to process.
• Loads your reply settings, including the OpenAI models to use, excluded sender patterns, and your greeting, signature, and tone preferences.
• Skips excluded senders (for example, “no-reply” and newsletter-style addresses) to avoid drafting replies where they don’t apply.
• Sends the email subject, sender, and body to OpenAI to classify whether the inbound message requires a personal reply.
• Generates a draft reply with OpenAI when needed, producing a plain-text response in the same language as the incoming email, following your greeting/signature rules.
• Creates a Gmail draft in the original conversation thread, addressed to the sender, so you can review and manually send.

Use cases

• Support and operations teams who want faster first responses without replying to newsletters or automated messages.
• SaaS operators triaging inbound inquiries and drafting consistent, on-brand replies.
• Automation engineers implementing AI-assisted Gmail workflows that generate drafts instead of auto-sending.

Technical details

• n8n Gmail Trigger (polling every minute) to detect new emails via your configured search query.
• if / set / no op logic to apply exclusions and route processing.
• OpenAI integration to decide whether a reply is needed and to generate the plain-text draft response.
• Gmail actions to create a draft reply in the same thread (requires Gmail OAuth2 access to read emails and create drafts).
• Additional supporting nodes such as a sticky note for workflow documentation.

Setup requirements

Connect your Gmail OAuth2 credential (read + create drafts) and an OpenAI API credential with access to the models you configured (e.g., gpt-5-mini and gpt-5.4). Then fine-tune your Gmail search query, excluded senders, greeting, signature, and tone.