SMTP server details have already been entered under System > Settings > General > Edit general sttings on the Enforce UI.

What should be the next step ?

Go to System > Servers > Alerts > Configure alert

Type in the alert name and the description.

Add Event type, Server or Event code conditions. It is better to go for the Event code condition. For Example : 1008,2301 etc.

Under actions type in the Email Recipient details for the notifications. It needs to be comma-separated list of email addresses

Below tech notes can also be referred to later on :

KB : Article ID: TECH220097: How to configure Enforce Server to send email alerts

KB : Article ID: TECH219194: System Monitoring Best Practices using Prevent

* Note : for more information you may refer to System event codes and messages section on the Admin guide.