NetSuite Marketing Campaign mails sending

Question

I would like to know the process of Marketing Campaign records. When we create a new record, we set the Target Group which is expected to receive email. The Target Group is of Employees. After the record is submitted, the email is sent but the Target Group doesn't receive it. I have set Marketing Preferences, Marketing Template as well.

I want to know which will be the scenario in which this Target Group will receive the emails. I want to know the customization or setting that needs to be done so that this thing will work.