Anyone that has online lead generation feeding into LionDesk will have bad email addresses. When these bounce, they can be tracked. However, you cannot remove them in bulk, like in other instances. If you have a lot of these (I have over 900 bounces), deleting 1 at a time would take several hours. Also, if you want to avoid sending bad emails that count against your monthly allotment, you have to get rid of them. I am actually stunned that this is not an option already.