That means the error email address is not authorized. You need to contact deliverability if you don't have the deliverability rights
update: I forgot to say that domain for the sender and error email need to be delegated by deliverability. If the domain is already delegated asked them to use *@domain instead of xxx@domain
Has your sub domain delegation happened by the deliver-ability team of Adobe? You need to reach out to them first for the sub domain delegation. They should be able to configure the mask for you as well.