If you are interested in checking only one type of mail, such as unread messages, in a container, you can list only those messages. Your changes are only in effect for as long as you have the container open. 
To list only a certain type of mail: 
1       Open the container. 
2       Click the pane you want to work with, if there are multiple window panes. 
3       Choose View > Filter, then one of the following: 
 You can also list only unread messages by default. 
 | ||||||||||||