restart without rebooting

[Virginia Chism]

I need to learn how to restart qmail on my BSDi system.  I have not been
able to locate a qmail-restart in any of the qmail directories.

Whenever I make changes in qmail, I have had to resort to `shutdown -r now`
thus rebooting the entire system.  I don't like doing this.

Someone told me to try 'killall -SIGHUP qmail', but someone else said this
might kill everything running - that the machine would not read to the
'qmail' at the end of the line.

Any suggestions?