From what I've seen, they get added to my program, but they also become unsubscribed. Some leads have forwarded their email to their alternate email (company email to a gmail or yahoo email). Because it's a newsletter, I went ahead and included them to the list, and they do have an option to unsubscribe, and so far, no unsubscribe. For now it's easy to monitor because it's only 10 records that got added overtime. Otherwise if it's a bigger number, I'd follow Craig's suggestion.