PART 1: BASE SYSTEM
Goal: install a Qmail system that supports sending and receiving email.
Architecture:
- Daemontools will handle starting, stopping, and serving programmes.
- TCPServer will listen on port 25 and invoke qmail-smtpd each time a connection is established.
- Qmail-Smtpd will talk to the user and eventually send mail
- Daemontools will invoke qmail-send to dispatch the email after qmail-smtpd is done