Gmail Sales Lead Labeling n8n Workflow with GPT-4.1-mini

Automatically label genuine sales emails in Gmail using GPT-4.1-mini

If your inbox is a mix of real buyer interest and constant noise (newsletters, vendor pitches, and cold outreach), this Gmail Sales Lead Labeling n8n workflow helps you surface the right messages fast. It uses OpenAI (GPT-4.1-mini) to classify new emails as sales leads and then applies a Gmail label—never sending, deleting, or drafting anything.

What this workflow does

• Checks Gmail every minute with a Gmail Trigger for newly received emails.
• Uses a Settings node to store your business name, the OpenAI model (default: gpt-4.1-mini), the target label (default: AI/Lead), and optional notes.
• Sends each email to OpenAI to determine whether it’s a genuine sales lead (someone who wants to buy from you). The model returns strict JSON containing:
  • is_lead
  • a short summary
  • a reason
• If is_lead is true, the workflow applies your Gmail label. If the label doesn’t exist, it creates it once (under parent AI) and then applies it.
• Skips cold pitches, newsletters, and cases where OpenAI output is invalid (treated as not-a-lead).
• Only adds labels. It never sends, deletes, or drafts emails.

Use cases

• Solo consultants and freelancers who need quick visibility into inbound purchase intent.
• Small business owners who want automated Gmail lead management without building a CRM.
• SaaS operators who want AI-assisted routing for sales conversations while keeping inboxes clean.

Technical details

• n8n nodes: Gmail Trigger, Set, Code, if, Gmail (label actions), Sticky Note.
• Integrations/credentials required: Gmail OAuth2 (for Trigger, Get/Create labels, Apply label) and OpenAI (for gpt-4.1-mini classification).
• Workflow behavior: minute-by-minute scanning, JSON-based lead detection, conditional label creation and application.