Microsoft KB Archive/274359

= LmCompatibilityLevel Setting Causes POP3/IMAP User Authentication Not to Work =

Article ID: 274359

Article Last Modified on 2/21/2007

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APPLIES TO


 * Microsoft Windows 2000 Server
 * Microsoft Windows 2000 Advanced Server
 * Microsoft Windows 2000 Professional Edition

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This article was previously published under Q274359



SYMPTOMS
POP3/IMAP clients are not authenticated correctly if your Microsoft Exchange-based server (which is also a domain controller) is configured to use NTLM version 2 authentication and the LmCompatibilityLevel setting is set to 5.



CAUSE
When the LogonUser function is called with LOGON32_LOGON_NETWORK, the function does not work if the LmCompatibilityLevel setting is set to 5.

Setting the LmCompatibilityLevel setting to anything other than 5 works correctly.



RESOLUTION
To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

260910 How to Obtain the Latest Windows 2000 Service Pack

The English version of this fix should have the following file attributes or later:   Date        Time       Version        Size     File name ---  01/25/2001  03:24 PM   5.0.2195.2842  130,320  Adsldpc.dll 01/25/2001 03:24 PM   5.0.2195.2835  348,944  Advapi32.dll 01/25/2001 03:23 PM   5.0.2195.2816  502,032  Instlsa5.dll 01/25/2001 03:24 PM   5.0.2195.2842  140,560  Kdcsvc.dll 01/17/2001 02:17 PM   5.0.2195.2842  198,928  Kerberos.dll 12/19/2000 10:13 PM   5.0.2195.2808   69,456  Ksecdd.sys 01/25/2001 03:24 PM   5.0.2195.2816  484,112  Lsasrv.dll 01/02/2001 09:45 AM   5.0.2195.2816   33,552  Lsass.exe 01/23/2001 06:06 PM   5.0.2195.2850  108,816  Msv1_0.dll 01/25/2001 03:24 PM   5.0.2195.2844  912,656  Ntdsa.dll 01/25/2001 03:24 PM   5.0.2195.2780  363,280  Samsrv.dll 01/25/2001 03:24 PM   5.0.2195.2797  128,272  Wldap32.dll



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Windows 2000 Service Pack 2.



MORE INFORMATION
For additional information about how to install Windows 2000 and Windows 2000 hotfixes at the same time, click the article number below to view the article in the Microsoft Knowledge Base:

249149 Installing Microsoft Windows 2000 and Windows 2000 Hotfixes

Keywords: kbhotfixserver kbqfe kbbug kbfix kbqfe KB274359

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