DOCUMENT:Q100709 21-DEC-2001 [pcmail] TITLE :SMTP: Err Msg: Network_read: Lost Network Connection PRODUCT :Microsoft Mail For PC Networks PROD/VER:MS-DOS:2.1,3.0 OPER/SYS: KEYWORDS:kbgraphxlinkcritical ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Mail Gateway to SMTP, versions 2.1, 3.0 ------------------------------------------------------------------------------- SYMPTOMS ======== Microsoft Mail Gateway to SMTP may display this message: ERROR Network_read: Lost network connection SMTP_recv: system error CAUSE ===== This error message appears if: - An error at the TCP or IP layer has occurred. - The other host has gone down. - The network between the Gateway computer and the other host has gone down. - The other host may require that the PUSH flag be sent to push the SMTP packet up to the SMTP software, instead of remaining in the incoming buffer. RESOLUTION ========== You can test these possible causes by attempting to telnet to port 25 of the smarthost and resending the message. This can usually be done by pressing SPACEBAR and typing "25" (without the quotation marks) after the IP address on the telnet command line. If the error message appears frequently, check the network with a protocol analyzer to determine the exact problem. NOTE: Mail sent to IBM TCP/IP Version 2, Release 2 may result in this error message if the PUSH flag is not set. FTP's pc/TCP automatically sets the PUSH flag for outgoing packets. For Microsoft LAN Manager TCP/IP, please contact Microsoft LAN Manager support for information on the availability to automatically set the PUSH flag. For Microsoft LAN Manager TCP/IP, ensure you are using version 2.2b (dated 2/1/94, 42,716 bytes) or later of the file TCPTSR.EXE. By default, TCPTSR.EXE is found in the LANMAN.DOS\DRIVERS\PROTOCOL\TCPIP directory. Then add the parameter ForcePushBit=1 to the [TCPIP] section of the PROTOCOL.INI file. It defaults to 0, but when it is set to 1, it causes the PUSH bit to be set on every outgoing packet. MORE INFORMATION ================ The following file is available for download from the Microsoft Download Center: DownloadDownload Tcptsru.exe now (http://download.microsoft.com/download/pcmail/Utility/20/WIN/EN-US/Tcptsru.exe) For additional information about how to download Microsoft Support files, click the article number below to view the article in the Microsoft Knowledge Base: Q119591 How to Obtain Microsoft Support Files from Online Services Microsoft used the most current virus detection software available on the date of posting to scan this file for viruses. Once posted, the file is housed on secure servers that prevent any unauthorized changes to the file. Additional query words: 2.10 3.00 ERRMSG smart host push flag ====================================================================== Keywords : kbgraphxlinkcritical Technology : kbMailSearch kbMailGateSearch kbZNotKeyword3 kbMailGateSMTP300 kbMailGateSMTP210 Version : MS-DOS:2.1,3.0 ============================================================================= 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 2001.