<p>Hi Rolf</p><p>Thank you for taking the time to respond. </p><p>I had increased the TCP/IP timeout to 180 seconds. That seems to work. I'm not seeing the errors now.  I'm also going to follow Thomas Stephenson's advise, and get the utility to run the MTU test.</p><p>Again, thank you.</p><p>Compton </p><p> </p>

<p>Hi all,</p><p>I'm using MercuryE to send mail. I've been recieving error messages on some mail - error reading   "Network write failure error during transmission to <ip address>".</p><p>Does anyone know what this means? Should I increase the timeout to 120 secs? </p><p>Any suggestions/help would be greatly appreciated.</p><p> </p><p>Thanks all,</p><p> </p><p>Compton </p><p> </p><p> </p><p>  </p><p> </p><p> </p><p> </p>

<p>Difficult to say without more information. Do you always get errors when sending to specific domains or recipients? If so you could switch on detailed logging while sending a test mail.</p><p>Does this happen mainly for messages with big attachments? If so it could be a fragmentation problem. Thomas Stephenson has some good advise regarding this that I've taken the liberty to copy below.</p><p>You can test increasing the TCP/IP timeout if you like to. If it works better without giving unnecessary delays in other cases it could be useful. 120 secs is still a reasonable value.  </p><p>/Rolf</p><p> </p><p><i>Thomas Stephenson: </i> </p><blockquote><div><i>A POP3/SMTP transmissions may fail if the </i></div><div><i>MTU packet size is so large that a packet is fragmented.  In many cases the receiving system </i></div><div><i>router blocks the receiving servers "packets fragmented" response to the sending system </i></div><div><i>using "MTU Discovery".  These oversize packets are not accepted and so are resent.  This </i></div><div><i>results in a timeout, generally at the end of the message transmission but it can be anywhere </i></div><div><i>in the process.  You need to reduce the MTU size. Windows defaults to a 1500 MTU and many </i></div><div><i>routers and DSL connections need 1492.  You might simply want to turn off the MTU Discovery </i></div><div><i>operation.</i></div><i> </i><div><i>You might want to get a copy of SG TCP Optimizer that I find quite handy.  </i></div><div><i><a href="http://www.speedguide.net/downloads.php" eudora="AUTOURL">http://www.speedguide.net/downloads.php</a>  This little utility will allow you to test your MTU for </i></div><div><i>maximum size without fragmentation against specific servers.  If will also make it easy to </i></div><div><i>adjust the MTU.  </i></div><i> </i><div><i>And finally, does this computer, by chance, happen to have an NVidia NForce 4 chipset on the </i></div><div><i>motherboard?  If so, many other have had this exact problem, and it turned out to be an </i></div><div><i>optimization setting for the built in NIC which caused the problems with packet fragmentation. </i></div><div><i>Disabling the advanced optimization capability called "checksum offload" made all the </i></div><div><i>problems of sending SMTP mail via WinPMail disappear.</i></div></blockquote>