Virtual User - ISP - usefull links
"spamassassin":http://www.spamassassin.org/dist/sql/README
"Postfix - Courrier Imap - MySql":http://www.high5.net/howto/
"Apache Config":http://www.unix-girl.com/geeknotes/apache_virtual_host_conf.html
"Pure FTP":http://www.pureftpd.org/README.Virtual-Users
"ProFTPD":http://groups.google.com/groups?q=virtual+user++ftp&hl=en&lr=&ie=UTF-8&oe=utf-8&selm=71z%25a.742110%24ro6.15224438%40news2.calgary.shaw.ca&rnum=5
" ISP-Planet Guide to Building an ISP":http://isp-planet.com/resources/isp_guide/index.html
"Scripts and Patches for Internet Service Providers":http://www.westnet.com/providers/