🚫 Spamhaus ZEN
Complete guide to the Spamhaus ZEN composite DNSBL: what listings mean, which sub-list you're on, and how to request delisting.
ℹ️ About This Blocklist
Composite zone combining the SBL (Spamhaus Block List), XBL (Exploits Block List), and PBL (Policy Block List). The most widely used DNSBL in the world.
What a Listing Means
The IP is a known spam source (SBL), an exploited or infected machine (XBL), or is in a policy-blocked range not intended for direct email delivery (PBL).
🔢 DNSBL Return Codes
When listed, the DNSBL returns one of these 127.x.x.x addresses. The specific code indicates the reason for the listing.
| Return IP | Meaning |
|---|---|
| 127.0.0.2 | SBL — direct spam source |
| 127.0.0.3 | SBL CSS — snowshoe spam operation |
| 127.0.0.4 | XBL — exploited/infected machine (CBL) |
| 127.0.0.9 | SBL — Spamhaus DROP/EDROP |
| 127.0.0.10 | PBL — ISP-maintained policy block |
| 127.0.0.11 | PBL — Spamhaus-maintained policy block |
✅ How to Request Delisting
Use the Spamhaus IP lookup tool to determine which sub-list you're on. SBL and XBL are self-serve. PBL removal requires contacting your ISP or using the Spamhaus PBL removal form.
Request Removal from Spamhaus ZEN ↗📚 Official Documentation
🔍 Check Your IP or Domain Against Spamhaus ZEN
Run a live blacklist check against all 17 blocklists we monitor, including Spamhaus ZEN.