SMTP: Err Msg: Error (116) Network Read Error

The information in this article applies to:

• Microsoft Mail Gateway to SMTP, versions 2.1 and 3.0

SYMPTOMS

Microsoft Mail Gateway to SMTP may display the following error message:

   Error (116) Network Read 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 gateway 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. FTPs pc/TCP automatically sets the PUSH flag for outgoing packets.

For Microsoft LAN Manager TCP/IP, ensure you are using the 2.2b version of the file TCPTSR.EXE. By default, TCPTSR.EXE is found in LANMAN.DOS\DRIVERS\PROTOCOL\TCPIP. The 2.2b version of TCPTSR.EXE is dated 2/1/94 and is 42716 bytes. 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.