Nothing is handier than knowing what you've sent and when you sent it. You can save all your outgoing mail in Outlook 2013 so that you can go back and look up the messages you've sent. Outlook starts saving sent items when you first install the program, but you can turn this feature on and off.
So before you go changing your options, look in your Sent Messages folder to see whether it contains messages. To save copies of your messages, follow these steps:
Select the File tab and click the Options button.
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The Outlook Options dialog box appears.
Click the Mail button in the navigation window on the left.
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The Mail settings appear.
Scroll down to the Save Messages section and select the Save Copies of Messages in the Sent Items Folder check box.
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If the box already contains a check mark, leave it alone. (That’s the way Outlook is set up when you first install it.) If you click the box when it’s already checked, you turn off your option for saving messages. Don’t worry if you make a mistake; you can always change it back. Just make sure that a check mark appears in the box if you want to save messages.
Click OK.