DOCUMENT:Q272492 08-MAY-2002 [winnt] TITLE :POP3 and IMAP Clients Are Not Authenicated on Exchange Server PRODUCT :Microsoft Windows NT PROD/VER::4.0,4.0 SP6a OPER/SYS: KEYWORDS:kbWinNT400PreSP7Fix ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server versions 4.0, 4.0 SP6a - Microsoft Windows NT Server, Enterprise Edition versions 4.0, 4.0 SP6a - Microsoft Windows NT Workstation versions 4.0, 4.0 SP6a - Microsoft Exchange 2000 Server ------------------------------------------------------------------------------- SYMPTOMS ======== When the Exchange Server 2000 registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\LSA has the LmCompatibilitylevel value set to 5, POP3 and IMAP clients are not authenticated. CAUSE ===== This issue occurs because the 5 value does not allow a check for clear text passwords, and authentication therefore does not work properly. RESOLUTION ========== A supported fix is now available from Microsoft, but it is only intended to correct the problem described in this article and should be applied only to systems experiencing this specific problem. To resolve this problem, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web: http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS NOTE: In special cases, charges that are normally incurred for support calls may be canceled, if a Microsoft Support Professional determines that a specific update will resolve your problem. Normal support costs will apply to additional support questions and issues that do not qualify for the specific update in question. The English version of this fix should have the following file attributes or later: Date Time Size File name Platform --------------------------------------------------- 25-Sep-2000 21:07 247,056 Advapi32.dll x86 25-Sep-2000 21:08 48,400 Msv1_0.dll x86 25-Sep-2000 21:06 403,728 Advapi32.dll Alpha 25-Sep-2000 21:06 79,632 Msv1_0.dll Alpha STATUS ====== Microsoft has confirmed this to be a problem in Windows NT 4.0. Additional query words: 4.00 ====================================================================== Keywords : kbWinNT400PreSP7Fix Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTSEntSearch kbWinNTSEnt400 kbWinNTS400sp6 kbWinNTS400search kbWinNTS400 kbExchangeSearch kbExchange2000Search kbWinNTSEnt400SP6a kbWinNTW400SP6a kbExchange2000Serv Version : :4.0,4.0 SP6a Hardware : ALPHA x86 Issue type : kbbug Solution Type : kbfix ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2002.