How does Outlook decide if an email goes to Focused or Other?

Outlook's Focused versus Other decision uses machine learning trained on individual user behavior. Several factors influence the prediction.

Sender relationship matters significantly. Messages from senders you frequently interact with, especially those you have replied to, trend toward Focused.

Engagement history with similar messages influences placement. If you consistently read newsletters from marketing senders, similar messages are more likely to appear in Focused.

Message characteristics play a role. Transactional messages, direct correspondence, and messages addressed only to you tend toward Focused. Mass marketing tends toward Other.

User training through explicit moves between tabs strongly influences the model. Moving a message to Focused teaches the system about your preferences.

Focused placement is earned through relevance. The more value you provide to each recipient, the more likely you appear where they look first.