SpamCop.net includes new spam traps on a regular basis. They also mix things up by reactivating spam traps that were as much as two years old.

Spam trap operators like SpamCop play an important role by identifying email abuse ranging from malicious botnets to inexperienced marketers who inadvertently send to bad lists. In order to be effective, SpamCop and other spam trap operators must update their networks frequently to capture enough data to identify abuse. So the fact that SpamCop has been deploying new traps without warning should come as no surprise. However, their recent tactic of reactivating old traps has caught some email marketers off guard.
Over the past several weeks, a lot of email marketers who thought they overcame the traps in October suddenly ran afoul once more, finding themselves on the dread blacklist. If you have encountered a higher incidence of SpamCop issues over the past thirty days, you might take a look at a couple of things.

First, eliminate the possibility that you’re getting caught by the October traps. If you were caught in October but were subsequently cleared, start by revisiting the batch of addresses from that time period. SpamCop usually clears a blacklisting after about 24 hours. If you send less frequently to a particular list, it may still contain one or more of the offending addresses. As a result, you could be getting caught by the October traps all over again.

Next you should look at older addresses to determine those that have been inactive. Given SpamCop’s most recent spam trap reactivation, go back at least two years. Regular scrubbing of old, inactive addresses from lists can help you avoid getting caught by spam traps and improve overall deliverability.