Categorize & Label Existing Gmail Emails with GPT-4o mini

This n8n workflow automates the organization of existing Gmail emails by analyzing unlabeled messages in bulk. Triggered manually, it fetches a batch (default 50) from your inbox, filters out already labeled emails, and sends the content to an AI Agent powered by GPT-4o mini for categorization. The AI outputs structured JSON via a parser, which a Switch node uses to route emails to specific Gmail label application nodes. All labels must pre-exist in your Gmail account and match the prompt-defined categories exactly.

Benefits include massive time savings for cleaning up cluttered inboxes, improved email searchability, and hands-off AI-driven sorting without coding. It's ideal for personal users overwhelmed by old emails or teams managing shared inboxes, freeing up hours for high-value tasks.

Use cases: Retroactively label thousands of newsletters, client inquiries, receipts, or promotions; prepare for audits by categorizing historical correspondence; or maintain a tidy inbox for better productivity. Pair with the incoming email version for complete automation. Requires Gmail API connection, OpenAI credentials, and pre-created labels.