What is the PSBL (Passive Spam Block List) and how does it work?

The Passive Spam Block List (PSBL) is a DNSBL listing IP addresses that send unsolicited email to spam traps. While it aims for easy listing and delisting, indicating a 'forgive and forget' approach, its effectiveness and usage by major ISPs are limited, resulting in a minimal deliverability impact for large providers. However, listing on PSBL signifies problems with email sending practices, specifically hitting spam traps and potentially indicating poor list hygiene. It's more likely used by smaller ISPs, so impacts there are more pronounced. Some experts believed it was defunct. Delisting occurs automatically after a period without detected spam.

The Passive Spam Block List (PSBL) is a DNSBL that identifies IP addresses sending spam to spam traps. While it has experienced shutdowns and isn't as widely used as other blocklists, it remains active. Listing on the PSBL, while potentially not drastically impacting deliverability across all ISPs, indicates problems with sending practices, especially regarding list hygiene and spam trap hits. Smaller ISPs and email providers are more likely to use the PSBL, making it crucial to maintain good sending practices to avoid listing.

The Passive Spam Block List (PSBL) is a DNSBL that lists IP addresses sending unsolicited emails to spam traps. Listing occurs when spam is sent to these specifically designed trap addresses. While its usage among major ISPs is limited, causing a minimal impact on deliverability for large providers, being listed indicates underlying list hygiene issues and hitting spam traps. PSBL is designed to be easy to get on and off, but consistent listings point to a need to address sending practices. Some believe it was defunct and are surprised it is still in use.

The Passive Spam Block List (PSBL) is a real-time DNSBL that identifies and lists IP addresses that have sent unsolicited email to addresses within the Passive Spam Trap Project. The PSBL uses unadvertised email addresses, or spam traps, to identify senders of unsolicited bulk email. Delisting is automatic after a period without detected spam, the length of which depends on the spam frequency. While its effectiveness can vary, it serves as an indicator of potential spam activity and can help to identify senders with poor list hygiene or compromised systems. The design is easy listing and delisting.