Thank you very much Croydon that did it!
I am trying to access http://giganetwirelss.net/webmail
and the server is returning 404 Not Found.
The only sites I have added to ISPConfig3 at this point are giganetwireless.net which is the primary server host and then giganetwirelss.com which is for our web-site.
Have you got an idea what I would check to restore access to 'webmail'?
Thank you once again