Trend Micro maintains a list of IP addresses belonging to known spam senders in a central database. Email Reputation filters spam by blocking the IP addresses stored in this database.

By default, anti-spam profiles in Deep Edge use Email Reputation, which is a Smart Protection Network™ component that verifies IP addresses of incoming email messages using one of the world's largest, most trusted reputation databases, along with a dynamic reputation database to identify new spam and phishing sources, stopping even zombies and botnets when they first emerge.