I concur, made those changes late last night and still seeing the problems this 
morning.

 

The only thing I have found that helps is to recycle the application pool on a 
timed basis of say every hour.

 

John T

 

From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Stephan
Sent: Thursday, March 29, 2007 7:43 AM
To: [email protected]
Subject: Re: [IMail Forum] TCP sockets & Windows -> maybe associated with 
2006.2 issues

 

I've made theses modifications a long time ago, which did fix some other 
problems with 2006.1, but I am still seeing problems with 2006.2 webmail with 
these tcp settings enabled.

-----Original Message-----
From: "Matt" <[EMAIL PROTECTED]>
Sent 3/28/2007 2:25:35 PM
To: [email protected]
Subject: [IMail Forum] TCP sockets & Windows -> maybe associated with 2006.2 
issues

I have run into TCP socket limitations with two different E-mail servers that 
run on Windows.  Both were the result of using too many TCP sockets.

Windows by default will only allow around 1,800 sockets to be used, and when 
you start getting to that point, unexpected things can happen.  Sockets are 
used for SMTP connections, POP3 connections, IMAP connections, DNS lookups, and 
all sorts of .NET stuff too.  Things like greylisting will keep sockets open 
for long periods of time, and systems that do spam blocking with DNS lookups to 
blacklists tend to push out more than is typical.  A good program designed to 
handle such load will pool the sockets in order to avoid hitting these limits.  
Both products that I had issues with introduced pooling in order to resolve 
these issues.

As a work around, or for tuning a Windows server that does such things, I 
recommend changing or adding the following registry parameters:

HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\MaxHashTableSize = 
65536 (DWORD)
HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\TcpTimedWaitDelay = 30 
(DWORD)
HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\MaxUserPort = 65534 
(DWORD)
HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\TcpNumConnections, 
16777214 (DWORD)

You can google each key name for a description of what they do.  This can 
definitely help if there are issues with the TCP sockets, but it's not a 
permanant solution.  The permanent solution is to have the application pool if 
it isn't already.

If this helps, it would definitely be good to share that with this list and/or 
Ipswitch in the event that they are still looking for the problem.

Matt

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