"This install process is not easy to do as there are
many commands and a lot of configuration that must be done without
mistakes. If you would like a Live Virtual Class for Postfix, click
on the link for more information. To get started you will need to
install postfix and dovecot-postfix.
"When you have the options to choose what type of mail site
select "Internet Site" and enter the domain you will use as the
canonical or main domain. Note the canonical domain cannot be
listed as a virtual domain.
"The next step is to use MySQL for the virtual users and
configure dovecot-postfix to connect to the MySQL database."