Postfix is Wietse Venema's mailer that started life as an alternative to the widely-used Sendmail program. It attempts to be fast, easy to administer, and secure, while at the same time, being sendmail compatible enough to not upset existing users. Thus, the outside has a sendmail-ish flavor, but the inside is completely different. This script builds postfix with optional support for Dovecot SASL, Cyrus SASL can be enabled with: SASL=cyrus ./postfix.SlackBuild You can also enable support for MySQL: DATABASE=mysql ./postfix.SlackBuild This script will find support for BerkleyDB and PCRE automagically; TLS support requires openssl package, openssl-solibs alone is not enough. Additionally, this script doesn't add postfix user and groups, instead it offers sane defaults that won't conflict with system users and groups, and other scripts from the SBo. Package created with this script will conflict with stock sendmail package, you *should* remove sendmail before installing postfix, otherwise sendmail updates could break your postfix instance. When upgrading from an older postfix version, make sure the variables such as html_directory and readme_directory in /etc/postfix/main.cf point to the new location. These can also be fixed later, afterwards make sure to run: postfix set-permissions Furthermore, many of the utilities in postfix have multiple manpages such as postconf(5) and postconf(8). Use man -k to find them, and don't forget to subscribe to the postfix-users mailing list!