XWEB: Suddenly and Permanently Unable to Reach Inbox Using Outlook Web Access

Some users may be unable to log on to their mailboxes by using Microsoft Outlook Web Access (OWA) if they use their SMTP addresses, and the following error message may be displayed:
This problem occurs suddenly, and it is permanent. In some cases, the users can log on to their mailboxes by using their aliases or their first and last names.

This problem does not occur if the users log on by using a MAPI client, such as Microsoft Outlook.

This problem occurs when the maximum size limit for user profiles is reached, which is 0x2000 (in hexadecimal) by default.

To resolve this problem, an administrator can increase the profile limit by changing the setting in the registry on the Internet Information Service (IIS) server.

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 Registry Editor (Regedt32.exe).
2. Locate the ProfileMemMaxSize value under the following key in the registry:
   HKEY_LOCAL_MACHINE\Software\Microsoft\Window MessagingSubSystem\Application\Inetinfo
   NOTE: The above registry key is one path; it has been wrapped for readability.
3. On the Edit menu, click DWORD, type 0x4000 , and then click OK.
4. Quit Registry Editor.
5. Stop and restart the IIS.

After an administrator performs these steps, the users are able to access their mailboxes by using their SMTP addresses again.

To work around this problem, use one of the following methods:

• An administrator can re-create the entry in the directory by moving the mailbox to another server or by using the Exmerge utility, and then deleting or re-creating the mailbox on the same server (many sites have only one server).
• Users can use their aliases or their first and last names to log on to their mailboxes when they use OWA.

With a modified version of the Logon.inc file, the following error message is logged: