qmail-conf is a collection of tools for setting up various qmail services.
They are like *-conf programs in djbdns.

With qmail-conf, for example, setting up a minimal SMTP service takes
the following four steps:

qmail-smtpd-conf qmaild qmaill /var/qmail/service/smtpd
cd /var/qmail/service/smtpd
make
ln -s /var/qmail/service/smtpd /service

qmail-conf assumes that (recent versions of) daemontools and
ucspi-tcp have already been installed. It also assumes that svscan
is already running.

qmail-conf tries to provide reasonable defaults: it avoids DNS
reverse lookups; it avoids IDENT lookups; it lets TCP connection
attempts be logged with multilog; and for POP3 and QMQP, connection
attempts are denied unless you explicitly authorize your clients.