E-mail messages take a long time to open in Outlook Web Access, and the Exchange computer is running IIS 5.0

Sometimes, e-mail messages take a long time to open in Microsoft Outlook Web Access. This issue occurs when the computer that is running Microsoft Exchange is running Microsoft Internet Information Services (IIS) 5.0.

This issue occurs when the URL that is used to open the e-mail message contains one or more period (.) characters. The period character may be in the subject line of the e-mail message or in the alias of the users mailbox (for example, "firstname.lastname"). Therefore, the period character may not be visible in the URL bar in the Web browser. To verify the presence of a period character in the URL, visit the IIS log.

To resolve this issue, add a loopback address (127.0.0.1) entry in the Hosts file. This loopback address entry maps to the period character.

Note If you use a front-end/back-end configuration on the computer that is running Exchange, you must add this entry to all front-end servers and back-end servers in your organization.

To add a loopback address, follow these steps:

1. In a text editor such as Notepad, open the following file:
   Drive:\WinDir\system32\drivers\etc\hosts
2. Under the 127.0.0.1 localhost entry, type the following entry:
   127.0.0.1 .
   Important The entry 127.0.0.1 is mapped to the period character.
3. Save the file, and then quit Notepad.
   
   Note Do not add a file name extension to the file name when you save the file.
4. Repeat steps 1 through 3 for each front-end server and back-end server in your organization.