DOCUMENT:Q303889 15-AUG-2002 [crossnet] TITLE :MX Record Failover Does Not Occur When 4xx Error Occurs PRODUCT :Windows for Workgroups and Windows NT Networking Issues PROD/VER::2000,2000 SP1,2000 SP2 OPER/SYS: KEYWORDS:kbenv kberrmsg kbnetwork kbtool kbSysAdmin kbWin2000PreSP3Fix kbWin2000sp3fix ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows versions 2000, 2000 SP1, 2000 SP2 Server - Microsoft Windows versions 2000, 2000 SP1, 2000 SP2 Advanced Server - Microsoft Exchange 2000 Server ------------------------------------------------------------------------------- SYMPTOMS ======== When an external DNS resolver is used on your Simple Mail Transfer Protocol (SMTP) virtual server, the next MX record is not tried when the host for the first MX record returns a "4xx" error. 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: Q260910 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 ---------------------------------------------------- 09/13/01 10:52 5.0.2195.4051 320,784 Aqueue.dll 09/13/01 10:52 5.0.2195.4051 66,832 Mailmsg.dll 09/13/01 10:52 5.0.2195.4051 38,160 Ntfsdrv.dll 09/13/01 10:52 5.0.2195.4236 435,472 Smtpsvc.dll NOTE: Before you apply the hotfix that is described in this article, install Windows 2000 Service Pack 2 (SP2) and Exchange 2000 Service Pack 1 (SP1). 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 3. Additional query words: kbMgmtAdmin esm ====================================================================== Keywords : kbenv kberrmsg kbnetwork kbtool kbSysAdmin kbWin2000PreSP3Fix kbWin2000sp3fix Technology : kbwin2000AdvServ kbwin2000AdvServSearch kbwin2000Serv kbwin2000ServSearch kbwin2000Search kbExchangeSearch kbExchange2000Search kbWinAdvServSearch kbWin2000AdvServSP2 kbWin2000AdvServSP1 kbwin2000ServSP1 kbwin2000ServSP2 kbExchange2000Serv Version : :2000,2000 SP1,2000 SP2 Hardware : 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.