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zen.spamhaus.org
Spamhaus ZEN
Spamhaus ZEN is the most widely used DNS blacklist in the world. It combines multiple Spamhaus lists — SBL (known spam sources), XBL (exploited systems), PBL (policy block list for dynamic/residential IPs) — into a single query. Being listed on Spamhaus can severely impact your email deliverability across most major providers.
Tier
Major
Impact
Very High — Used by the majority of email providers worldwide. A listing here can block your emails almost everywhere.
Auto-expiry
XBL listings auto-expire once the exploit is cleaned. SBL listings require manual removal. PBL listings are policy-based.
What it lists
Known spam sources, compromised/exploited hosts, and IP ranges that should not be sending unauthenticated email (e.g., residential or dynamic IPs).
How to get delisted
- 01Visit the Spamhaus IP lookup tool at check.spamhaus.org
- 02Enter your IP address and check which specific list you appear on (SBL, XBL, or PBL)
- 03For SBL listings: Identify and stop the spam source, then submit a removal request via the form
- 04For XBL listings: Clean the malware/exploit from your system — the listing will auto-expire once resolved
- 05For PBL listings: This is a policy listing — configure your mail server to relay through your ISP's SMTP server, or request removal if you run a legitimate mail server
Open the removal formhttps://check.spamhaus.org/listed/