This is a detailed description about the steps to be taken to setup a Ubuntu based server (Ubuntu 5.10 - Breezy Badger) that offers all services needed by ISPs and hosters (web server (SSL-capable), mail server (with SMTP-AUTH and TLS!), DNS server, FTP server, MySQL server, POP3/POP3s/IMAP/IMAPs, Quota, Firewall, etc.).

I will use the following software:

• Web Server: Apache 2.0.x

• Mail Server: Postfix (easier to configure than sendmail; has a shorter history of security holes than sendmail)
• DNS Server: BIND9
• FTP Server: proftpd
• POP3/POP3s/IMAP/IMAPs: in this example you can choose between the traditional UNIX mailbox format (we then use ipopd/uw-imapd) or the
• Maildir format (in this case we will use
• Courier-POP3/Courier-IMAP).

• Webalizer for web site statistics

In the end you should have a system that works reliably and is ready for the free webhosting control panel ISPConfig (i.e., ISPConfig runs on it out of the box).

Full Article.