I apologize for the delay in responding. In the future, please create a ticket here: https://codemonkeysllchelp.freshdesk.com/support/tickets/new
Typically there are 2 issues with notification emails. The first is that they are not working at all. SMTP plugin should resolve.
For plugin-specific issue, typically it is with the setup. Most likely the from email. Some sites will not all generic emails to be sent (gmail, for example). Others will have constraints for @domain.com to avoid spoofing.
Here is the the setup information. Please create a ticket if you still need assistance.
https://codemonkeysllchelp.freshdesk.com/support/solutions/articles/48000946433-e-mail-notification-options
