Gmail GPT-5 Email Labeling n8n Workflow Automation

Automatically label your Gmail with GPT—powered by n8n

This Gmail GPT-5 Email Labeling n8n workflow watches your inbox for new Gmail messages, classifies each email with OpenAI, and then automatically applies the correct Gmail label to keep your inbox organized—without manual sorting.

What this workflow does

• Monitors new emails: Triggers every minute whenever a new message arrives in Gmail.
• Classifies email content with OpenAI: Sends the email sender, subject, and snippet to OpenAI and requests exactly one category from your predefined list.
• Maps category → Gmail label ID: Converts the returned category into the corresponding Gmail label ID.
• Uses a safe fallback: If the category is missing or unexpected, the workflow applies a default label ID you provide.
• Applies the label: Updates the original Gmail message with the selected label automatically.

Use cases

• SaaS operators: Auto-label lead vs. support vs. billing messages to route work faster.
• Automation engineers: Maintain a consistent labeling taxonomy using OpenAI classification.
• Inbox management: Reduce manual inbox triage by enforcing category-based Gmail labels.

Technical details

• Trigger: Gmail Trigger (checks every minute for new messages).
• Processing: Set and Code nodes to prepare inputs and map categories to Gmail label IDs.
• AI classification: Uses the n8n-nodes-langchain LLM node (Chat Model set to the model you choose) to classify emails into one category.
• Gmail actions: Applies the selected label via the Gmail label action.
• Notes: Includes a sticky note for workflow guidance.

Setup

Connect your Gmail OAuth2 credentials for the Gmail trigger and label action, add your OpenAI API credentials, and set the OpenAI Chat Model. Then replace the placeholder taxonomy with your real Gmail label IDs (including the default label ID), and optionally adjust the category list to match your labeling scheme.