Microsoft Outlook’s Focused Inbox feature helps its users categorize their inbox based on interest, splitting mail into a Focused tab and an Other tab. It’s similar to Gmail's Primary tab. Emails landing in the Focused Inbox are considered safe by spam filters, and future emails from the sender are less likely to be filtered out. Focused Inbox is still Microsoft’s current model — it works in classic Outlook, the new Outlook for Windows, and Outlook on the web — but placement is decided entirely by the recipient’s app and their own actions, so you can’t force it. The reliable way in is to send mail people want, authenticate your domain, and let recipients mark you as Focused.