Fig. 1 By default, messages are grouped and sorted by date.
The type of arrangement.
How messages are ordered. In this case, the newest messages are on top.
Outlook displays only relevant date information depending on the age of the message.
To see the full date, hover the mouse over the displayed date.
Fig. 2 The Arranged By shortcut menu.
By default, Outlook shows messages grouped and sorted by date. In this arrangement, as shown in Figure 1, notice how Outlook simplifies what you see by hiding unnecessary details. For example, messages received today show the time only. Messages from yesterday show the day and time, while messages that are older than a week show you dates only.
You can also arrange messages other ways: by size, by who they're from, or by subject (to name just a few).
To quickly change from one arrangement to another, you would click Arranged By (as shown in Figure 2) and select the choice that suits you.