I need to make a script to start the postfix service on a server when the machine starts up.

I have a script written below, which I think will work, but I am confused on how the rc2.d & rc3.d etc directories actually work.

If I enter the script below, and stick it in the rc3.d directory, will it start the postfix service?

What i am confused on is, does the S25postfix filename tell the system to run the script with the start option? and the K25postfix tell the system to run it with the stop option?

here is the script, will this work if i drop it into the proper rc directories with the K or S prefix?

#!/sbin/sh
#
#
#
#
#START POSTFIX SERVCIES

case "$1" in
'start')
/usr/sbin/postfix start
;;

'stop')
/usr/sbin/postfix stop
;;

*)
echo "Usage: $0 { start | stop }"
;;
esac
exit 0