Configuration of this program in the typical case is quite simple.

1. Compile and install the program.  If you are using the RPM, skip this
step.  See the INSTALL file for more details.  Note that this package is
designed to execute as a non-privileged user named "nullmail".  When you
do the final install, add the "nullmail" user (typically with either a
non-privileged group or a new "nullmail" group) and run "make
install-root" to set up the files with the proper permissions.

2. Set up your hostname in SYSCONFDIR[1]/nullmailer/me.  Usually this
   will be as simple as typing:
	/bin/hostname >SYSCONFDIR/nullmailer/me
   You may also wish to set up the defaultdomain and defaulthost
   configuration files.  See the man page for nullmailer-inject for more
   details.

3. Into the file SYSCONFDIR/nullmailer/remotes, put one line for each of
your relay hosts (the computer or computers to which you will send all
your mail):
	HOSTNAME PROTOCOL
You will have specified the SYSCONFDIR during configuration of the
install step.  On most systems, it will be /usr/local/etc.  The RPMs use
/etc.  HOSTNAME is the fully-qualified host name of the relay host, or
its numerical IP address.  PROTOCOL will typically be "smtp" (without
the quotes), but QMQP[2] is also supported with the "qmqp" module.

4. Start nullmailer-send.  If you are using the RPM, ignore the rest of
the instructions and type:
	svc-start nullmailer
Otherwise, you will need to set up the appropriate scripts to run
nullmailer-send in the background, with its output going to a logging
program.  The following is an appropriate run script for use with
daemontools[3]:
	#!/bin/sh
	exec setuidgid nullmail nullmailer-send 2>&1

5. You're done!  The included sendmail emulator front-end should allow
most (if not all) sendmail-compatible programs to run without any
changes.  See the man page for nullmailer-inject for details on outgoing
email message header formatting options.

Footnotes:
1. SYSCONFDIR is the system configuration directory, as configured
during compilation.  It defaults to /usr/local/etc
2. QMQP is a high-speed mail queueing protocol, used with qmail.  See
http://cr.yp.to/proto/qmqp.html
3. See http://cr.yp.to/daemontools.html.