Reply to Gmail with Gemini + HubSpot via Slack Approvals (n8n)

Draft Gmail replies with Gemini—then get Slack approval first (HubSpot + n8n)

This n8n workflow monitors your Gmail for new inbound emails, enriches each message with CRM context from HubSpot, drafts a concise reply using Google Gemini, and sends the draft to Slack for approval. Only after you approve in Slack does it send the reply back in the original Gmail thread.

What this workflow does

• Watches Gmail every minute for new inbound emails.
• Filters out blocked senders using a sender domain rule (configured to block addresses containing "n8n.io" in the default example).
• Enriches the email with HubSpot CRM data by searching for the contact by the sender’s email address, then pulling associated deals, companies, and tickets via the HubSpot CRM API.
• Generates a ready-to-send draft with Google Gemini by sending the email content plus the normalized HubSpot context to the Gemini chat model.
• Sends the draft to Slack in a selected channel and waits for an approval response.
• Replies in Gmail only after approval, posting the drafted text into the original email thread.

Use cases

• Sales and support teams who want consistent, CRM-aware responses without manually searching HubSpot.
• Forwarding “approval-needed” emails through Slack to reduce risk while still responding quickly in Gmail.
• SaaS operators managing inbound messages where every reply should reflect the latest deal, company, or ticket status.

Technical details (n8n + integrations)

• Gmail: trigger for inbound emails and Gmail reply action.
• Slack: posts draft replies and waits for approval.
• HubSpot: contact lookup and retrieval of associated deals, companies, and tickets via HubSpot CRM API.
• Google Gemini (Google AI Studio): drafts the reply text based on email + HubSpot context.
• Nodes used: if, code, gmail, slack, filter, hubspot.

Setup checklist: connect Gmail credentials (trigger + reply), HubSpot OAuth2 (CRM access), Google Gemini credentials, Slack OAuth2 (target approval channel), and update the blocked sender rule to match your policy.