Email blocklist · DNSBL · IP addresses
TUE · 28 JUL 2026
Passive Spam Block List
About
Maintained by a small team; conservative listing criteria emphasise correctness over coverage. A useful complement to higher-coverage lists like Spamhaus.
Listing criteria
Passive listings sourced from automated honey-pot traps. Conservative listing criteria; relatively low false-positive rate.
How to query
For an IP address 1.2.3.4, query reversed-octets-dot-zone:
dig +short 4.3.2.1.psbl.surriel.comA returned IP (such as 127.0.0.2) means listed. Each blocklist has its own set of return codes meaning different things; the operator's documentation explains theirs.