How to make a droplet send email?

Hi,

I have installed CSF as the firewall for my droplet by following this tutorial: https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-config-server-firewall-csf-on-ubuntu

Now, in the sub-heading called Process Tracking, it says that CSF can be configured to send emails to the system admin about the various firewall processes. My questions are:

1. Where do I add the system admin email id?
2. I have CentOS with MySQL, PHP, Apache running. Will this automatically ensure system emails being sent out or do I need to add some email system?

Thanks in advance.