Mystery Meat revisited: Spam, Anti-Spam Measures and Digital Redlining

In order to protect email users from receiving unsolicited commercial email or spam, anti-spam measures building on technologies, such as filters and block lists, have been deployed widely. However, there is some evidence that certain anti-spam measures based on the purported origin of the spam cause unintended consequences related to issues of equity of access, which we term digital redlining. In this article, we revise and expand earlier work looking at secondary effects of anti-spam measures.