The addresses 'should' be auto reported to providers via a bolt on system & Xenforo's own scheme, though it makes no real odds as there'll be another script somewhere constantly generating new email accounts. (If they're even real accounts, and not just redirected to one big spoof confirmation address.) All so needless. We've all seen forums & sites buried/abandoned under this crap. Usually smaller/niche places. Even here in the dim & distant Owen pretty much single-handedly kept the place clean during a disinterested owner's few months of possession/abandonment.