XFOR: POP3 Clients Cannot Log In with Clear Text Authentication through Membership Server

POP3 clients cannot gain access to a Microsoft Exchange Server information store when logging on using clear text authentication and the authentication type for the POP3 interface in Exchange Server is configured to be MCIS Authentication (meaning it will use Membership Server). In Exchange Server 5.5, there is currently no provision to allow clear text authentication through Membership Server.

Microsoft recognizes the need for POP3 clients to be authenticated with clear text authentication through Membership Server. We have modified Exchange Server 5.5 so that it is now possible for POP3 clients to access an Exchange Server using clear text authentication through Membership Server.

To obtain this feature, obtain the latest service pack for Exchange Server version 5.5. For more information, please see the following article in the Microsoft Knowledge Base:
The English version of this feature should have the following file attributes or later: This feature was first included in Exchange Server 5.5 Service Pack 2.

In addition to the new files noted above, the following registry changes must be made to enable this functionality. To make the registry changes, perform the following steps:

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it.

1. Stop the Microsoft Exchange Information Store service.
2. Apply the fixed files noted above.
3. Start Registry Editor (Regedt32.exe).
4. Go to the following location in the registry:

        HKEY_LOCAL_MACHINE\CurrentControlSet\Services\MSExchangeIS
        \ParametersSystem

5. On the Edit menu, click Add Value.
6. In the Value Name box, type MBS Package.
7. Set the Data Type to REG_SZ.
8. Click OK.
9. In the String box type MBS_BASIC.
10. Click OK.
11. Again, on the Edit menu, click Add Value.
12. In the Value Name box, type MSB Broker.
13. Set the Data Type to REG_SZ.
14. Click OK.
15. In the String box, type the instance ID of the MBIS broker instance (for example, 3).
16. Click OK, and quit Registry Editor.
17. Restart the Microsoft Exchange Information Store service.