For POP3 accounts, Outlook can be configured to leave messages on the server indefinitely or for a specified period of time. To edit this preference:

  1. Click File / Account Settings.
  2. Make sure the E-mail tab is selected and click your email account.
  3. Click the Change button.
  4. Click the More Settings button.
  5. Click the Advanced tab.
  6. In the Delivery section, make sure the box is checked next to “Leave a copy of messages on the server.
  7. To leave messages on the server for a specified number of days, make sure the box is checked next to “Remove from server after” and enter the number of days for messages to be saved on the server.
  8. Click the OK button.
  9. Close the Change Account window.
  10. Click the Close button in the Account Settings window.