The Spamikaze Passive Spam Block List (PSBL) is an IP-based blocklist (blacklist) that lists addresses sending mail to spamtraps, featuring an easy, user-driven removal process designed to minimize false positives.
The Spamikaze Passive Spam Block List (PSBL) is a DNS-based blacklist (DNSBL) that aims to reduce false positives through a simple listing and delisting policy. It's designed to be an "easy-on, easy-off" list, where users can quickly remove their mail server's IP address if it is listed by mistake. This blocklist does not perform active tests for open relays or proxies. Instead, its listing decisions are based entirely on emails received by its network of spam traps.
The core principle is that most hosts sending spam are not legitimate mail servers. This blacklist (or blocklist) operates with a straightforward policy:
IP addresses are automatically removed from the list after a certain period. The goal is that legitimate mail servers, if listed, are only on the blacklist for a short time before their administrators notice and request removal. In contrast, compromised machines or 'zombies' used for spamming may remain on the list for much longer. This approach helps block spam without severely penalizing legitimate senders who may have been briefly compromised.
The Spamikaze Passive Spam Block List (PSBL) is powered by Spamikaze, which is a collection of programs designed to build and manage a spam blocklist. The software itself is passive, meaning it works by analyzing mail that comes into its spamtrap network rather than actively probing servers on the internet. To minimize false positives, Spamikaze uses regular expressions to filter out potential non-spam messages and also maintains whitelists to prevent known mail servers from being listed on this blacklist.
Spamikaze is available as free software under the GNU General Public License (GPL), making it accessible for anyone who wants to operate their own spam block list.
Removal from the Spamikaze Passive Spam Block List (PSBL) is a straightforward, self-service process. Anyone can request to have an IP address removed, which is a key part of its design philosophy. The idea is that a legitimate user can easily delist their server, while a spammer managing hundreds or thousands of compromised IPs would find it too time-consuming to delist them all from every individual blacklist.
To remove your IP address, you can use the form on their website. Remember to enter the IP address of your mail server, not your email address. Once you submit the form, the removal is instantaneous from the PSBL database. However, due to DNS caching across the internet, it may take some time for the change to propagate to all mail servers.
The impact of being listed on the Spamikaze Passive Spam Block List (PSBL) is considered medium. While it is used by system administrators globally, it is not as widely adopted as some of the largest industry blocklists. A listing on this blacklist will likely cause email delivery failures to recipients whose mail providers use the PSBL. Because of the easy delisting process, the impact can often be resolved quickly by removing your IP address from the list.
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