How do MBPs use engagement and trust to rank emails?

MBPs use engagement and trust as core ranking signals to determine inbox placement. Engagement measures how recipients interact with your emails: opens, clicks, replies, forwards, and time spent reading. Trust encompasses your authentication setup, sending history, and reputation scores.

When users consistently engage positively with your emails, MBPs learn that your messages are wanted and valuable. This builds trust over time, improving your placement priority. Conversely, low engagement signals disinterest, while spam complaints signal active distrust.

The combination creates a feedback loop. Good engagement builds trust, which improves placement, which enables more engagement. Poor engagement erodes trust, worsening placement, which further depresses engagement. This is why maintaining list hygiene and sending relevant content to engaged subscribers matters so much for long term deliverability.