Hello Christian
Did you added contact objects to the notification rule for the object that you are testing with?
Did you verified that the notification template is set to active and Auto notification is set to "Yes"?
Did you verify in the logs if the issue is related with the mail server and not with the notification itself?
By default this notification is active but there are no contacts added to the rule, therefore no notification would be sent.
Please verify and let us know what you found.
Best Regards,
Ruben Reyes
CA Support Engineer