Disable Socket Pooling
IIS 6 (Windows 2003 Server)
To disable HTTP socket pooling you need a tool named httpcfg.exe' which is available from the support tools on a Windows Server 2003 CD-ROM. (\support\tools\support.cab)
Open a command prompt and type:
net stop http /y
This stops all IIS services.
httpcfg set iplisten -i IP:80
Substitute the IP with the appropriate IP address on which you want to have IIS listening.
NOTE: List the IP Addresses (with ports) that you want IIS to LOCK, not the IP that you want Icewarp's Web Server to use.
A successful change will result in:
"HttpSetServiceConfiguration completed with 0" being displayed.
Now you can run another application on port 80 on different IPs other than you used for IIS. Sometimes, it will be necessary to reboot the server after this change but you can try to start IIS by net start w3svc
Microsoft article: here
To disable SMTP socket pooling you should run a command prompt, go to c:\IntePub\AdminScripts folder and run following command:
cscript adsutil.vbs set /smtpsvc/1/DisableSocketPooling true
IIS 5 (Windows 2000 Server)
Open a command prompt and browse to the C:\InetPub\AdminScripts folder. Then type:
cscript adsutil vbs set w3svc/DisableSocketPooling TRUE
cscript adsutil.vbs set /smtpsvc/1/DisableSocketPooling TRUE
The first command disables HTTP socket pooling and the second one disables SMTP socket pooling. Reboot the server after that.
Microsoft article: here , and here