> > How do I turn off sendmail on my netbsd 1.5.2 box?

Now I see that you are the same person working with qmail -- so now I have
different comments :)

The sendmail command is just a wrapper.

$ ls -l `which sendmail`
lrwxr-xr-x  1 root  wheel  21 Oct 21  2000 /usr/sbin/sendmail ->
/usr/sbin/mailwrapper

Have a look at /etc/mailer.conf and the mailer.conf(5) and mailwrapper(8)
manual pages. Then if you want to use this method, set /etc/mailer.conf up
to point to your qmail tools. Maybe something like:

sendmail        /var/qmail/bin/sendmail
send-mail       /var/qmail/bin/sendmail
mailq           /var/qmail/bin/qmail-qstat
newaliases      /var/qmail/bin/newaliases

(Note that mailq and other tools behave slightly different.)

Good luck,

   Jeremy C. Reed
   http://www.reedmedia.net/