Hello all, Our Exchange systems forward all mail to a 'Smart Host' that resides in our DMZ. The Smart Host is nothing more than a Windows 2003 Server with IIS SMTP services and GFI Mail Essentials and Mail Security. As far as blocking/preventing SPAM and Virus' mail - it works GREAT. My problem is that the SMTP service seems to flake out 2 to 3 times a week here lately. The SMTP service is still running and receiving mail from Exchange, and it receives mail from the internet, but the queues will back up and not deliver the mail at all... A reboot of the server will get the server to process mail again and flush out the queues... Restarting the services does nothing to assist and there are no events in any of the logs. Can anyone point me to any information that indicates what mail volumes the standard IIS SMTP mail service can handle? I want to verify that we are not overwhelming the service with too much volume. Regards, Chris