The Focus Pane lets you focus on what's important by temporarily hiding everything that isn’t relevant to the task at hand. For example, you can use the Focus Pane to view:
Unread messages from my boss
Reminders from this month
Messages from Sally with tag Project X
The Focus Pane zeros in on messages by attribute (such as being unread or having an attachment), contact, Topic, and date. These criteria can be mixed and matched to fine-tune the view.
The Focus Pane is also fully customizable–you can hide or show attributes, add favorite contacts or Topics, and reorder them by priority.
To view the Focus Pane type command/control-shift-p, or select Show > Focus Pane from the View menu.