What are “user engagement signals” in Gmail’s model?

User engagement signals in Gmail's model are behavioral indicators that reveal whether recipients find your emails valuable. These include opens, clicks, replies, forwards, and time spent viewing messages. Negative signals include deleting without opening, marking as spam, and consistently ignoring messages.

Gmail weights these signals relative to the user's overall behavior. If someone opens most promotional emails, not opening yours is a stronger negative signal. If someone rarely engages with any marketing, low engagement with your emails matters less.

The aggregation of these signals across your recipient base shapes your sender reputation at Gmail. High engagement rates signal that your mail is wanted, improving placement priority. Low engagement suggests your messages may not be valuable to recipients, triggering more aggressive filtering or Promotions tab placement.