You can hide messages in a message list. To hide messages, select the messages that you want to hide, then choose View -> Hide Selected Messages.
To hide messages that you have read, choose View -> Hide Read Messages.
To show hidden messages, choose View -> Show Hidden Messages. When you show
Email and Calendar does not show
To show deleted messages, choose View -> Hide Deleted Messages. The deleted messages appear in strikethrough format in the folder from which you deleted the messages.