[linuxvadapav] need help for postfix installation

[Sukhdev Jadhav]

Hi,
I have to install postfix for local mail delivery. (Similar to
Postmaster in Windows)
My basic requirement is to download mails from another mail server and
distribute in local network.
We have 10 users in Mumbai branch and main server is located in Delhi.
We need to install postfix with Courier Imap and squirellmail.
Distro is Whitebox EL 4.
Can anybody guide me or give me any link?
I will be very much thankful for any reply.