for ns6
yum install http://mirror.de-labrusse.fr/NethDev/nethserver-yum-cron/nethserver-yum-cron-0.0.1-1.ns6.sdl.noarch.rpm
for ns7
yum install http://mirror.de-labrusse.fr/NethDev/nethserver-yum-cron/nethserver-yum-cron-0.1.3-1.ns7.sdl.noarch.rpm
You have several differences between ns6 and ns7, due to the yum-cron version. Some big changes has been done.
For both the default recipients is root now, the random starts is set to 60 minutes whatever the version, and this below is still right
By default, the notifications are sent and you download the updates. All notifications are sent to the root user. If you need it, you can direct the notifications on other email addresses, of course I can not do the settings of your smarthost, please verify in /var/log/maillog if you don’t receive the emails, why they are bounced.
Each day a cron job starts during the night (after a random sleep time) and looks after update.