Select the "System Settings" tab on the left side of the page then the "Administration" tab at the top.


Under the "GUI access" heading, you can change your HTTPS port, allowed network addresses, and GUI authentication password. More information on this section can be found here.


Scroll down to find the "E-mail notifications" section. Here, you can set your SMTP account settings. 

Test!  Your settings and results depend on your setup!