Messageware NavGuard is a security product designed to protect Outlook Web App (OWA) sessions from unauthorized access caused by users navigating away without logging off. It monitors OWA usage and detects navigation events — such as URL entry, browser back/forward button use, refresh, or home button clicks — that would leave an active session exposed on shared or public computers. When a navigation event is detected, NavGuard presents the user with a prompt offering the choice to log off before proceeding or return to the active OWA session. This prevents subsequent users on the same computer from accessing a previous user's OWA session without re-authentication. NavGuard extends the protections provided by forms-based authentication (FBA) and other perimeter security products. Administrators can configure custom security policies based on criteria including logon ID, security group membership, IP address, and corporate device recognition. Policy management is handled through a centralized administration console.