Outlook Web App, also known as Outlook Web Access, or OWA, is an integral part of Microsoft Exchange Server. It allows you to access your Exchange mailbox from any location, using only a Web browser. Although this is certainly an extremely useful feature, the standard mobile OWA GUI is feature-limited when compared to the desktop version.
OWA For Smartphone is a server-based, client-independent Outlook Web Access add-on. Install it on your Microsoft Exchange Client Access Server or any other available IIS Web Server to give your mobile workers access to all features of their mailboxes, using only the browser on their SmartPhone.
OWA For Smartphone is the most effective way to extend Outlook Web Access email and collaborative functionality (including all mailbox Folders, Contacts, Calendar, Tasks, Notes, Address Lists and Public Folders) to mobile computing devices. It does not in any way affect Exchange's existing components or operation.