The Outlook web application has an automatic time out. The automatic time-out is valuable because it helps protect a user's account from unauthorized access. However, although the automatic time-out greatly reduces the risk of unauthorized access, it does not completely eliminate the risk that an unauthorized user could access an Outlook Web App account if a session is left running on a public computer. To reduce this risk, use the Log Off button in OWA when you are finished using email, and close the Web browser after logging off.