Hi Marc,
This works in this way. When you create an e-mail campaign you can also let the system assign a task to the account owners in case there are e-mail bounces where the account owner should follow-up to update the master data. So it will create a notification when an email bounce happens considering the fact that you have enabled Enhanced Marketing Functionalities option in Business configuration. For more info. and clearity on this plz. check Handling E-Mail Campaigns in user guide.
Regards,
Saurabh