This is a detailed description how to set up a CentOS 4.3 based server 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/IMAP, Quota, Firewall, etc.). This tutorial is written for the 64-bit version of CentOS 4.3, but should apply to the 32-bit version with very little modifications as well.