Design Implementation


The Email Blocklist (EBL) contains email addresses, most of which are used to receive responses to spam emails. These email addresses are sometimes called contact email addresses or drop boxes. The initial target of this blocklist was "Nigerian" 419 Advance Fee Fraud spam. As time passed and more types of spam that used drop boxes was identified, these drop boxes also were listed. The EBL now lists significant numbers of drop boxes used in spam sent by mostly-fraudulent dating/hookup sites, mostly fraudulent SEO/web development companies, direct spam services, list sellers, and a number of other fraudulent or outright illegal products and services. It also lists apparently-legitimate manufacturers of high-tech and light industrial products, purveyors of business and professional training, and many other types of otherwise-legitimate businesses and organizations that spam.

The features that these types of spam have in common are:

As of March 2018 the EBL is in production. Low-volume users -- private individuals, small businesses, and small non-profit organizations that operate their own mailservers -- can query the public mirrors without cost. Companies or organizations that have over 100 users should contact the EBL reseller, SecurityZones, to arrange for commercial access.

For information and links to tools that can assist you in implementing the EBL on your mailserver, see the Implementation page.


Finally, the EBL team owes more than a few thank yous. While it would have been possible to design a blocklist without reference to existing blocklists, it would have been neither easy nor wise. The team hesitates to name names, for fear of leaving somebody important out, but there are a few teams and specific people whom we must recognize.

In addition, the team is grateful to spam filter designers, antispam researchers, and mail administrators who have beta tested the EBL and provided valuable feedback.