What are the key ranking factors for Gmail inbox placement?

Gmail's key ranking factors for inbox placement center on domain reputation, user engagement, and authentication compliance. Domain reputation matters most: Gmail evaluates your sending domain's history across all senders using it, not just your specific campaigns.

User engagement signals heavily influence placement. Gmail tracks whether recipients open your emails, click links, reply, forward, or conversely ignore, delete without reading, or mark as spam. Consistent positive engagement builds trust; consistent negative signals trigger filtering.

Authentication is table stakes. Valid SPF, DKIM, and DMARC are required for bulk senders. List quality factors in through bounce rates and complaint rates, with Gmail enforcing strict thresholds. Finally, content quality matters, though less than reputation, with Gmail's AI analyzing for spam patterns, misleading subject lines, and phishing indicators.