You receive a "Sorry! The Microsoft Exchange Server Is Down" error message in OWA (180417)

WORKAROUND

1. Verify that the HTTP service is enabled at the site level. To do this, follow these steps:
   
   
   1. Start the Exchange Server Administrator program.
   2. Click the Site container in which the server is located, click the Configuration container, and then click the Protocols object.
   3. Open the HTTP (Web) Site Settings object, and verify that the Enable Protocol option is enabled.
   NOTE: In some cases where the HTTP protocol has been disabled, the Logon.asp screen reappears and an error message is not displayed.
2. Verify that the Lightweight Directory Access Protocol (LDAP) protocol is enabled at the site or server level and that the Allow Anonymous Access option is enabled for the LDAP protocol at the site or server level. To do this, follow these steps:
   1. Start the Exchange Server Administrator program.
   2. Click the Site container in which the server is located, click the Configuration container, and then click the Protocols object.
   3. Verify that the Protocol Enabled option is enabled.
   4. Open the LDAP (Directory) Site Defaults object, and click the Anonymous tab.
   5. Verify that the Allow Anonymous Access option is enabled.
   6. Now that you have verified the site settings, you need to verify the server settings. To do this, click the Protocols object of the server that you are connecting to.
   7. Open the LDAP (Directory) Settings object, and click the Anonymous tab.
   8. Verify that the Allow Anonymous Access option is enabled.
3. Verify that the MSExchangeWeb registry key contains the correct values for the Organization, Site, and Server names of the Exchange Server computer that you are connecting to. To do this, follow these steps:Warning If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
   
   1. Start the Exchange Server Administrator program.
   2. Note the Organization, Site, and Server names that are displayed for the server that you are connecting to.
   3. Start the Registry Editor (Regedt32.exe) on the Exchange Server computer.
   4. Select the following registry key:

      \HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeWeb\Parameters

   5. Verify that the following three values match the names found above:

      Enterprise - (Must match the organization name)
      Site - (Must match the site in which the server is located)
      Server - (Must match the server to which you are connecting)

      If any of the above values are incorrect, change them to match the names that the Exchange Server Administrator program displays.
      
      NOTE: These values are not case sensitive.
   6. Quit the Registry Editor.
   7. In Control Panel/Services, stop and restart the World Wide Web Publishing Service.
      
      NOTE: You must start and stop the WWW service with the Control Panel/Services. In some reported cases, stopping and starting the WWW service in the Internet Service Manager program has not corrected the problem.
4. Verify that the WWW Anonymous Logon account (IUSR_machine name) on the Microsoft Internet Information Services (IIS) is at least a member of the Domain Users and Guests groups. This account must have the proper Windows NT credentials to access the IIS and Exchange Server. This may be an issue if you are attempting to access an Exchange Server computer that is located in another domain. Another alternative is to specify an account from the Domain Administrators group as the Anonymous Logon account for the WWW service. To change this account, perform the following steps:
   1. Start the Microsoft Internet Service Manager (ISM).
   2. Click the WWW service.
   3. Click the General tab, and then type an existing Windows NT account name and password for the Anonymous Logon option.
   4. Click OK, and then quit the Internet Service Manager.
5. Exchange Server version 5.5 introduces a new right (and role) called Search, which controls read access of the Exchange Server directory. To enable this functionality for an account on any object in the Exchange Server directory, you must first define an anonymous account on the General tab of the DS Site Configuration object. After you do this, any account can be granted the Search permission on any object in the directory. However, the Anonymous account must also be explicitly granted Search permissions at the Configuration container level.
   
   To verify whether Search permissions have been enabled within the Exchange Server directory, check the Permissions tab of the Organization, Site, and Configuration containers. If any account has been given the Search permission, you also need to grant this right on the Configuration container to the Anonymous account specified in the DS Site Configuration object.
   
   The other alternative is to remove the Search permission for all accounts from each object in the Exchange Server directory that has this permission set.
6. Verify that all Web Access files have been installed on the server and that they are the proper versions. This scenario may occur if any MAPI- enabled applications (Exchange or Microsoft Outlook clients, UPS systems, and so on) were not closed or disabled before running the Setup program. Because Exchange Server is forced to use older versions of certain system files such as the Mapi32.dll file, the OWA components may not function correctly. To verify that the files are correct, perform the following steps:
   1. Run Exchange Server Setup and choose the Reinstall option. This runs through the last successful installation and updates any corrupt or missing registry entries and system files.
      
      -or-
   1. If you have made any customizations in the \Webdata directory, you must back up the directory.
   2. Run Exchange Server Setup, choose the Add/Remove option, and remove the Outlook Web Access (5.5) components. Complete the Setup to uninstall these components.
   3. Run Setup again to add the OWA components. This creates a clean \Webdata directory.
7. In the Exchange Server Administrator program, in the properties of the organization-level container, make sure that the Display Name is the same as the Directory Name. Do the same thing with site-level container.
8. If you are using Address Book Views and the Service account has search rights at the Organization level, remove Address Book views from the Exchange Organization, or enable a valid anonymous account in the DS Site Configuration object. This would typically be the IUSR account that is created by the IIS. Verify that the password that is set in the DS Site Configuration object matches the password for this account in the User Manager tool. When the passwords match, the user can log on correctly and see the Address Book view that he or she belongs to. If the passwords do not match, the error message that is mentioned in the "Symptoms" section may occur.