Please explain the interaction between the 'Send Notification Email to event creator' in the Configuration, and the notification email setting in the Event Advanced Setting.
If 'send to event creator' is yes and I put the owner's address in the event setting will the owner be sent two emails? If 'event creator' is yes and I put a different address in the event setting will they both receive the emails.
When you set send to event creator to Yes, event creator (if he is not super admin) will receive notification email (independent with emails entered into Notification Emails parameter)
So Yes, if you enter his email into Notification Emails, he will end up with receiving two emails. If you enter a different emails, both event creator and the emails entered into Notification Emails config option will receive notification