> 00:42:41.859 << 0002 \0D\0A
> 00:42:41.859 << 0003 .\0D\0A
> 00:43:34.828 7: Socket read error 2746.
> 00:43:43.906 << 0006 QUIT\0D\0A
> 00:43:43.906 9: Socket write error 2746.
Typical packet fragmentation indication. The POP3/SMTP transmissions may fail if the MTU packet size is so large that a packet is fragmented. In many cases the receiving system router blocks the receiving servers "packets fragmented" response to the sending system using "MTU Discovery". These oversize packets are not accepted and so are resent. This results in a timeout, generally at the end of the message transmission but it can be anywhere in the process. You need to reduce the MTU size. Windows defaults to a 1500 MTU and many routers and DSL connections need 1492. You might simply want to turn off the MTU Discovery operation.
You might want to get a copy of SG TCP Optimizer that I find quite handy. http://www.speedguide.net/downloads.php This little utility will allow you to test your MTU for maximum size without fragmentation against specific servers. If will also make it easy to adjust the MTU.
And finally, does this computer, by chance, happen to have an NVidia NForce 4 chipset on the motherboard? If so, many other have had this exact problem, and it turned out to be an optimization setting for the built in NIC which caused the problems with packet fragmentation. Disabling the advanced optimization capability called "checksum offload" made all the problems of sending SMTP mail via WinPMail disappear.
&gt; 00:42:41.859 &lt;&lt; 0002 \0D\0A
&gt; 00:42:41.859 &lt;&lt; 0003 .\0D\0A
&gt; 00:43:34.828 7: Socket read error 2746.
&gt; 00:43:43.906 &lt;&lt; 0006 QUIT\0D\0A
&gt; 00:43:43.906 9: Socket write error 2746.
Typical packet fragmentation indication.&nbsp; The POP3/SMTP transmissions may fail if the MTU packet size is so large that a packet is fragmented.&nbsp; In many cases the receiving system router blocks the receiving servers "packets fragmented" response to the sending system using "MTU Discovery".&nbsp; These oversize packets are not accepted and so are resent.&nbsp; This results in a timeout, generally at the end of the message transmission but it can be anywhere in the process.&nbsp; You need to reduce the MTU size. Windows defaults to a 1500 MTU and many routers and DSL connections need 1492.&nbsp; You might simply want to turn off the MTU Discovery operation.
You might want to get a copy of SG TCP Optimizer that I find quite handy.&nbsp; http://www.speedguide.net/downloads.php&nbsp; This little utility will allow you to test your MTU for maximum size without fragmentation against specific servers.&nbsp; If will also make it easy to adjust the MTU. &nbsp;
And finally, does this computer, by chance, happen to have an NVidia NForce 4 chipset on the motherboard?&nbsp; If so, many other have had this exact problem, and it turned out to be an optimization setting for the built in NIC which caused the problems with packet fragmentation. Disabling the advanced optimization capability called "checksum offload" made all the problems of sending SMTP mail via WinPMail disappear.
