What is PSBL (Passive Spam Blocklist)?

You send a campaign, everything looks fine on your end, and then a deliverability check flags your IP on something called PSBL. What even is that?

PSBL (Passive Spam Block List) is a trap-based blocklist that records IP addresses caught sending email to spam traps. The word "passive" is the key here. PSBL doesn't go hunting for spammers. It just sits quietly with a network of trap addresses and notes who mails them.

If your IP hits one of those traps, you get listed. No human reviews it. No complaint form triggers it. The trap itself does all the work.

How you end up on PSBL:

• You're sending to an old or purchased list that contains trap addresses
• Your ESP's shared IP pool has had a previous sender hit traps
• Your list hygiene has slipped and you're mailing addresses that were once real but have since been recycled as traps

What it means for deliverability: PSBL has a relatively low deployment footprint compared to major lists like Spamhaus. Most major mailbox providers don't rely on it directly. That said, some mail servers and spam filters do query it, so a listing isn't something to ignore.

The good news on delisting: PSBL listings expire automatically once the spam activity stops. You don't need to file a removal request or wait for a human to review your case. Stop hitting the traps, and the listing ages out on its own. You can check your current status and see the expiration timeline at psbl.org/listing.

If you're showing up on PSBL, the real question is how trap addresses got into your list in the first place. That's usually a sign your list needs a clean. You can run it through our list validation service to catch those risky addresses before they cause more damage, or check whether you're on any other blocklists with our free blocklist checker.