From wiki

Setup Notifications

By default email sent from cron will go to <username>@<hostname> which is a bit of a pain to setup mail filters when you get multiple machines and multiple usernames.

The solution is to add near the top of the /etc/crontab

This apply to all crontab entries bellow this line. Which mean that you can get per entry email by having multiple MAILTO lines.

Note: You need to add this line in all crontab files. This mean /etc/anacrontab if it exist as well as users crontab.