How do I disabling Email output?
By default the output of a command or a script (if any produced),
will be email to your local email account.
To stop receiving email output from crontab you need to append >/dev/null 2>&1.
For example:0 3 * * * /root/backup.sh >/dev/null 2>&
To mail output to particluer email account let us say vivek@nixcraft.in
you need to define MAILTO variable to your cron job:
MAILTO=”vivek@nixcraft.in”
0 3 * * * /root/backup.sh >/dev/null 2>&1
More details:
http://www.cyberciti.biz/faq/how-do-i-add-jobs-to-cron-under-linux-or-unix-oses/