Deploying and troubleshooting Outlook Web Access

Microsoft Outlook Web Access (OWA) for Microsoft Exchange Server provides users access to e-mail, personal calendar, group scheduling, and collaboration applications on Microsoft Exchange Server with only a Web browser. Outlook Web Access is implemented by a combination of Microsoft Active Server Pages technology on the Web server side, and Java controls and scripts downloaded on demand to the user's Web browser.

Due to this lightweight client design, the only interface end-users must have is a compatible Web browser, and all the workload of the client is then pushed up to the Web server running the Outlook Web Access component. This design is helpful to organizations and users who want a quick, easy access to an Exchange Server mailbox, while requiring little to no additional software installed on the client computer. OWA can be a great solution for a kiosk environment, or simply for users who need quick access to their Exchange Server mailbox without having a full MAPI client installed.

However, these lightweight clients do force the Web server (which is actually the computer running Internet Information Server 3.0 or 4.0 with the OWA component installed), to be responsible for handling all the client connections. In essence, each Web client to connect is another MAPI session to be created on the OWA server, and in each of these sessions, we ask the OWA server to poll the Exchange Server computer for the data, and then render results back to the Web browser. This additional workload on a Web server should be planned for before deploying OWA. Then after deployment, you should monitor your OWA server workload to ensure user access to the Web server is not overwhelming the server.