This article discusses authentication time-out values for Microsoft Outlook Web Access (OWA).
Time-out values for an OWA session
Users are automatically logged off OWA after a period of inactivity. The time-out period of an OWA session depends on whether a user selects the This is a public or shared computer option or the This is a private computer option when the user logs on to OWA.
By default, the time-out values are set in Microsoft Exchange as follows:
This is a public or shared computer
The OWA session ends, and the user is automatically logged off after 15 minutes of inactivity.
This is a private computer
The OWA session ends, and the user is automatically logged off after 8 hours of inactivity.
However, be aware that there are circumstances that override these default values. If a company uses two-factor authentication, an authentication server is located in front of the OWA server. Although a user's session may time out against a particular authentication server, the user's session in OWA remains active until the time-out setting for the logon option that the user selected is reached.