Gmail tabs

Gmail tabs (introduced in 2013) automatically categorize inbound mail into Primary, Promotions, Social, Updates, and Forums. The Primary tab is for personal-feeling mail; Promotions is for marketing; Social is for notifications from social networks; Updates is for transactional and notification mail; Forums is for mailing-list traffic.

Gmail's categorization is based on content patterns, sender characteristics, and recipient behavior. Marketing emails almost always land in Promotions by default. Users can override by dragging messages between tabs or by disabling the tabs entirely.

Tab placement is not a deliverability failure — Promotions is still the inbox, just a different folder. Engagement is lower on Promotions than Primary (opens drop 30–50%, clicks similarly), but engaged subscribers do check Promotions intentionally. Trying to game Primary placement on bulk marketing email tends to backfire; focus on engagement (which improves tab placement long-term) and let Gmail categorize honestly.