My company's current layout.
Internet-----ISP router-----WinGate box (also gateway, mail server)-----internal clients (35 clients)
The Wingate box is running on XP Pro sp2. It is a single point failure.
I want to have a linux box which act just like the Wingate box in case it crashed.
1) What distro and version should I choose (server or clients)? Where to download?
2) What option should I choose for email? Currently we have outllook as clients and Mdaemon as server from www.altn.com
3) For securiy purposes, what is the best way for this Linxu box to act as a gateway and wingate? IPTABLE?
4) How about proxy?
5) What is the best way to install this linux box so that it is hardend?
Please take it easy on me. I completely new in Linux. Thanks,