What does Gmail’s “smart labels” system do?

Gmail's smart labels system automatically categorizes incoming email into tabs: Primary, Social, Promotions, Updates, and Forums. Machine learning models analyze content, sender identity, and user interaction patterns to determine which category best fits each message.

The system aims to organize the inbox by email type rather than forcing users to manually sort everything. Social notifications go to Social, marketing emails to Promotions, transactional receipts to Updates, and mailing list messages to Forums.

For senders, smart labels mean your marketing emails likely land in Promotions rather than Primary. This is not spam filtering but organizational filtering. Users who check their Promotions tab still see and engage with your emails. The key is that placement in Promotions does not indicate deliverability problems, it reflects Gmail's understanding of your email's purpose.