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BlacklistMonitoring
IP blacklist ยท Spamhaus

Spamhaus ZEN lookup and removal

Combined Spamhaus IP blocklist (SBL, CSS, XBL and PBL in one query). Used by most large mailbox providers and corporate filters; a ZEN hit usually means rejected mail. Check your IP below, then follow the removal steps if it is listed.

Checks run by DNS only. Nothing is sent from or to your domain.

How to get removed from Spamhaus ZEN

Spamhaus ZEN removals go through the operator's lookup and removal portal. Fix the cause first, then request removal for the listed address.

  1. 1 Look up the IP address on the operator's site and read the listing reason and return code.
  2. 2 Find the cause on the sending host: a compromised mailbox or script, an open relay, a missing or generic PTR record, a sudden volume spike or a stale list hitting spam traps.
  3. 3 Fix the cause before asking for removal. A list that relists you quickly usually takes longer to remove you the second time.
  4. 4 Open the removal page (https://check.spamhaus.org/), enter the listed IP address and follow the confirmation steps (often an email link).
  5. 5 Re-check the IP address here after the next zone update to confirm the listing is gone. Monitoring alerts you if it comes back.

Spamhaus ZEN at a glance

OperatorSpamhaus
DNS zonezen.spamhaus.org
ListsIP addresses
Impact on deliveryHigh
RemovalOperator lookup and removal portal
Removal pagecheck.spamhaus.org
IPv6Supported

What the Spamhaus ZEN return codes mean

A DNS blacklist answers with an address in 127.0.0.0/8 when something is listed. The last part of the address tells you why.

Return codeMeaning
127.0.0.2SBL, Spamhaus maintained spam source
127.0.0.3SBL CSS, low reputation sending detected
127.0.0.4XBL, exploited or infected host
127.0.0.9SBL DROP, hijacked or criminal network
127.0.0.10PBL, ISP maintained end user range
127.0.0.11PBL, Spamhaus maintained end user range
127.255.255.252Query refused or error, not a listing
127.255.255.254Query refused or error, not a listing
127.255.255.255Query refused or error, not a listing

Frequently asked questions

How do I check if I am listed on Spamhaus ZEN?

Enter your sending IP in the check box on this page. We query zen.spamhaus.org by DNS and show the result with the return code and what it means.

How do I get removed from Spamhaus ZEN?

Spamhaus ZEN removals go through the operator's lookup and removal portal. Fix the cause first, then request removal for the listed address.