What are malicious bot signups?

Bot signups are automated fake subscriptions to email lists. Bots fill signup forms with: invalid addresses (causing bounces), spam traps (damaging reputation), or real addresses belonging to others (causing complaints).

Purposes: list bombing (flooding victim inboxes), reputation attacks (damaging sender through bounces/complaints), and resource consumption (wasting sender capacity and costs).

Impact: bounces from invalid addresses harm deliverability, trap hits trigger blocklisting, and complaints from unwitting recipients damage reputation. Bot signups cause multi-dimensional harm.