Skip to main content

What signals decide which tab an email lands in?

Tab classification evaluates multiple signals:

Content patterns: Marketing language, promotional offers, commercial formatting push toward Promotions.

Sender characteristics: Bulk sending patterns, commercial domains, known marketing platforms.

Message structure: HTML templates, tracking pixels, unsubscribe links suggest commercial content.

Historical classification: How this sender's messages were previously categorized.

User behavior: If a user moves messages between tabs, Gmail learns their preferences.

Personal, conversational messages with minimal formatting tend toward Primary.

The harbor master classifies your cargo based on what it looks like, where it came from, and how similar shipments were handled before.