[pmmail-list] PMmaill cannot send bigger eMails - It stops after some Kbytes of transmission

[Ben Stover]

Hello,

I have a very special problem on one of my PMMail installations on a WinXP system.

When I sent bigger eMails (e.g. > 100 KB) then the upload speed is at first normal but then slows down and finally halts at approx 57 kB forever.
The eMail is NOT sent.
This problem occurs for all my PMMail accounts but it does NOT occur when I sent the same
eMail over e.g. Thunderbird and it does NOT occur when I sent the same email with PMMail from another, second computer.

Because this problem appears only since a few weeks the reason must be found in some modifications of underlying TCP DLLs
on my WinXP system - not in PMMail itself.  
I could have (accidentially) changed some OS parameter/configuration settings which prevent sending bigger eMails.

Can someone tell me what problem is?

Is there a log which shows more verbose the SMTP protocol and transfer progress ?

Regards
Ben