i want to monitor the proxy server uses by the user so isthere any free tools so can i keep tracknig of proxy/internet use
To monitor proxy by users you need proxy to use authentication to have actual usernames loged. In my case I use authentication and then Sarg to show me all reporting.
also i want mail server uses tool and network monitoring tools
Nagios is a very powerfull tool. I use it along with RRDTool to also have graphs ;) You can also try Cacti - looks very nice as well, but I believe nagios is more powerful. -- Best Regards, Alexander Mamchenkov http://alex.mamchenkov.net