Chapter 22, Microsoft Outlook Web Access

|1| Chapter Overview Outlook Web Access Overview Outlook Web Access Environments Chapter 22, Lesson 1 Outlook Web Access Overview

|2| 1. Microsoft Outlook Web Access (OWA) Architecture A. Requires Microsoft Windows 2000 Server and Internet Information Services (IIS) 5.0 B. IIS behaves, as usual, like a Web server and accepts requests from Web browsers for access to mail, and then authenticates the user. C. IIS then passes the request to the OWA Internet Server Application Programming Interface (ISAPI), which uses Active Directory directory service to determine the home server of the mailbox. D. If this is an OWA front end server, the request is proxied to the user’s home server. E. If this is the mailbox’s home server: 1. Permissions are checked. 2. The Exchange Installable File System (ExIFS) uses the Information Store service to provide access to mail and public folder messages. 3. The Exchange Object Linking and Embedding Database provider (ExOLEDB) uses the Information Store service to provide access to forms. F. OWA renders the item, and IIS returns the Web page to the user’s Web browser.

|3| 2. Outlook Web Access File Locations A. With the exception of the DLLs that define the default templates used to render OWA, most files are located in the \Program Files\Exchsrvr\Exchweb folder. B. Five directories are important for OWA: 1. \Program Files\Exchsrvr\Bin contains the server’s general executables and DLLs. 2. \Program Files\Exchsrvr\Exchweb\Bin holds setup files for Outlook 2000 Multimedia Extensions. 3. \Program Files\Exchsrvr\Exchweb\Controls contains server-side and client-side script files. 4. \Program Files\Exchsrvr\Exchweb\Lang contains localized versions of OWA help files, only created if non-English languages are enabled. 5. \Program Files\Exchsrvr\Exchweb\Img contains logos and other graphics used by OWA. |4| 3. Default Virtual Directories Created During Exchange 2000 Server Setup A. Exadmin is an OWA client used by the administrator to manage public folders. B. Exchange is used to access the root of the mailbox folder structure. C. Exchweb is used to open graphics and other support files. D. Public is used to access the public folder tree.

|5| 4. Outlook Web Access Considerations A. Data security issues 1. Only basic authentication is supported, so you need to enable Secure Sockets Layer (SSL) for secure access. 2. When you’re done reading your e-mail, close the browser so others can’t use the Back button to read your e-mail. 3. Disable the Save Password feature of Microsoft Internet Explorer 5.0. 4. Disable local caching on the browser, especially if your browser doesn’t support no-cache directives. Be aware that over slow links, this setting will degrade performance. 5. Clear the browser cache manually when reading sensitive e-mail. B. OWA supports all browsers as long as the browser supports Java scripts and HTML 3.2. C. Install audio/video support for e-mail messages. Chapter 22, Lesson 2 Outlook Web Access Environments

|6| 1. Single-Server Configurations A. Provide direct client access to mail and public folders B. Client access is through IIS and the default Hypertext Transfer Protocol (HTTP) virtual server. C. Once Exchange 2000 Server is installed, all users have automatic Web access to e-mail. D. You can optionally create additional virtual servers to meet your company’s security requirements. E. You must provide the fully qualified domain name (FQDN) for Web access if you are not working within your home domain.

|7| 2. Front End/Back End (FEBE) Configurations A. Typically used when supporting a large number of users over the Internet B. Front end servers receive client requests and then find the user’s home server by using Active Directory. C. User mailboxes can be moved to different servers without needing to reconfigure the client because the client access point is always the front end server.

2 Outline, Chapter 22 Microsoft Exchange 2000 Server Implementation and Administration D. Make sure that the Public and Exchange virtual root names on the front end server correspond to the names on the back end server.

|8| 3. Front End Load Balancing A. Round-robin Domain Name System (DNS) can be implemented to achieve load-balancing on your front end servers. 1. It must be enabled on the Advanced tab for the DNS server. 2. Multiple front end servers provide fault-tolerance to your design. 3. Because the nature of Windows 2000 DNS is to prioritize IP addresses, round-robin DNS doesn’t always work as expected. B. Round-robin DNS should not be used with SSL. If a client is redirected between servers, new sessions need to be established to regenerate the bulk encryption key.

|9| 4. Resource Access A. Controlling access permissions 1. IIS is used to manage security settings and properties for the Default Web Site. 2. Exchange System Manager is used to control access to virtual directories and to set authentication requirements. 3. Active Directory Users and Computers is used to enable or disable OWA on a per-user basis by using the Protocol Settings option on the Exchange Advanced tab for the user. B. Validated resource access 1. IIS can obtain your logon credentials automatically when using Internet Explorer versions 4.0 and 5.0, eliminating the need to provide a FQDN or password. 2. You can access any mailbox that you have permission to by typing in your Web browser’s Address box http:///Exchange/ if you are working in your home domain, or http:///Exchange/ if you are accessing remotely (where is the name of your server, is your alias, and is the URL of your Microsoft OWA server). C. Anonymous resource access 1. Be careful! It may not be what you think! 2. The system uses the IIS guest account called IUSR_ (a real Windows 2000 account) to allow anonymous access. 3. The anonymous account receives the permissions assigned to the Default user because of the “real account” status. 4. A best practice is to not allow anonymous access to the Messaging Application Programming Interface (MAPI)-based public folder tree because anonymous users will have the permissions of your Default user. 5. A best practice is to mail-enable the IUSR account so that you can assign it client permissions.

Outline, Chapter 22 3 Microsoft Exchange 2000 Server Implementation and Administration D. Disable the Exchange Virtual Server by right-clicking the virtual server in Exchange System Manager and selecting Stop.

|10| 5. Backward Compatibility Issues A. Exchange 2000 OWA can’t access public folders on older versions of Exchange. B. Exchange 5.5 OWA can access mailboxes and public folders on Exchange 2000 servers as well as on Exchange 5.5 servers. C. A best practice is to replicate public folders on legacy Exchange servers to Exchange 2000 servers. D. Active Server Page (ASP)-based customizations won’t be preserved when upgrading from legacy versions of Exchange to Exchange 2000 Server.

|11| Chapter Summary Outlook Web Access Overview Outlook Web Access Environments

4 Outline, Chapter 22 Microsoft Exchange 2000 Server Implementation and Administration