There are 2 ways to prevent cron to send out e-mail notifications once the cron is executed:
01. Simply append one of the following directives to the end of your script to be executed.
so the cronjob will look like the following
* * * * * command /path/to/the/file >/dev/null 2>&1
* * * * * command /path/to/the/file &> /dev/null
Save and close the file. Restart the crond:
# /etc/init.d/crond restart
02. By editing the MAILTO variable in the cronjob
# crontab -e -u username
Save and close the file.