Overview
PSBL (Passive Spam Block List), maintained by Surriel.com, is a passive detection list based on spam traps. Unlike active-scanning blacklists, PSBL only logs IPs that send email to its trap addresses β no proactive scanning.
PSBL is known for fast auto-expiry β without new trap hits, listings clear very quickly.
How It Works
PSBL operates a large number of undisclosed trap mailboxes spread across various domains. Any IP that sends email to these addresses gets logged and listed. Since these addresses were never published or registered for anything, legitimate mail servers shouldn't be contacting them.
How to Get Delisted
PSBL offers a whitelist feature β submit your IP at psbl.org, and after verification you can join the whitelist to prevent future listings. For temporary listings, simply stop triggering traps and the listing typically clears within hours.