Ubuntu comes with the mail command (part of mailutils) which can be used to send email notifications. First, you need to install mailutils:
sudo apt-get install mailutils
Ensure that your system can send emails by setting up a simple Mail Transfer Agent (MTA). postfix is commonly used:
sudo apt-get install postfix
/usr/local/bin/clamav_scan_notify.sh sudo chmod +x /usr/local/bin/clamav_scan_notify.sh sudo crontab -e 0 3 * * * /usr/local/bin/clamav_scan_notify.sh
/usr/local/bin/snort_notify.sh sudo chmod +x /usr/local/bin/snort_notify.sh sudo crontab -e 0 * * * * /usr/local/bin/snort_notify.sh