Again, if you receive only 5 to 10 messages daily, each message is likely pretty important-or at least it would seem to be in the eyes of a computer program attempting to separate the wheat from the chaff. The accuracy of identifying important correspondents is much better when a large number of messages are processed. Facing a large Inbox can be a depressing task, especially after you return to the office after an extended vacation-unless you wasted many precious hours of vacation time dealing with email just to keep the volume under control. However, if you receive a couple hundred new messages each day, you might be grateful for some assistance to isolate the really important items from the flood of notifications, spam, company updates, personal chatter, and so on. If you receive only 5 to 10 messages a day, you probably don't need a lot of help to identify important messages in your Inbox. The usefulness of People View and Clutter increases in line with the rate of messages received daily. The Clutter feature removes unimportant items, whereas People View identifies and highlights email received from your most important correspondents.
Both features filter items as they arrive in the Inbox. The goal of People View and the new Clutter feature (another new feature available to users of OWA for Office 365) is to help users process large mailboxes much more efficiently. The idea is that because these messages have come from a person who is important to you, they're highlighted in a way that makes the items much more obvious and quickly accessible. If you click an entry in the list, OWA displays a view of all the messages that the person sent to you since People View was enabled (in my case, the middle of April 2014). It displays a list of the people with whom you interact most often and includes a count of unread messages from each person. Exchange makes its choice by observing your inbound and outbound traffic. Similarly, People View is a set of views (one for each selected person) that's automatically built and updated by Microsoft Exchange Server based on the people with whom you correspond. You're unaware of the search because it happens automatically behind the scenes. To make this feature work, Outlook performs a search on your behalf to build a view showing all the unread messages. For example, when you click the Unread Mail search folder in Outlook, you see unread messages that exist in all folders in the mailbox. In some respects, the People View feature is similar to Outlook's search folders, which have been around for years. It's an interesting technology that deserves some explanation about how the people (or correspondents) who appear in the view are selected and what the new feature is intended to do. Microsoft has rolled out the new People View feature in Outlook Web App (OWA) for Office 365. NB: As of May 2015, Microsoft has deprecated the People View feature in Office 365.