Blacklist checker
To check a blacklist, enter your sending IP or domain. ZapBounce queries Spamhaus and the other public blocklists receivers consult, and shows each list's return code and reason text in a few seconds, free and with no signup.
The short version
- Enter an IPv4 address to check the IP lists, including Spamhaus ZEN. Enter a domain to check the domain lists, including Spamhaus DBL.
- A clear row means that list has nothing against you today. A red row shows the list's own code and reason, which names the fix.
- Listed on Spamhaus ZEN or on several lists at once? Stop the sends from that host and find the cause before you ask for removal.
- Most listings start with mail to dead or abandoned addresses, so clean the list with the bulk email verifier before the next send.
How the Spamhaus check works
Spamhaus runs the blocklists most mail servers consult. The checker queries two of their zones, one for IP addresses and one for domains.
Spamhaus ZEN is one lookup that covers three lists. The SBL lists IPs seen sending spam. The XBL lists hijacked machines and infected hosts. The PBL lists ranges that should never send mail straight to the internet, such as home broadband. You'll see which one matched from the return code.
The Spamhaus DBL lists domains found in spam: the sender's domain, link domains and tracking domains. It catches senders who rotate IPs but keep the same domain in every campaign, so check your sending domain and your link domain both.
A PBL listing is policy, not a penalty. It means that IP should hand mail to a proper mail server first. If your mail goes out through an email provider, the IP that matters is theirs, and the email header analyzer shows you which one it was.
| Spamhaus ZEN code | List | What it means for you |
|---|---|---|
| 127.0.0.2 | SBL | The IP was seen sending spam or is under a spammer's control. Fix the source, then open a removal ticket. |
| 127.0.0.3 | SBL CSS | Low-reputation mail came from this IP, often a bad list or a hacked form. It clears once the traffic stops. |
| 127.0.0.4 to 127.0.0.7 | XBL | A machine on this IP is infected or hijacked. Clean the host, then use the self-service removal. |
| 127.0.0.9 | SBL DROP | The whole range is hijacked or run by spammers. Move to a different provider. |
| 127.0.0.10 and 127.0.0.11 | PBL | The range should not send direct to the internet. Send through a mail server or your provider. |
Return codes as documented by Spamhaus, checked September 2026. Codes in 127.255.255.0/24 are query errors, not listings, and the checker never reports them as a listing.
The blocklists this checker queries
| List | Checks | How much receivers use it |
|---|---|---|
| Spamhaus ZEN | IP addresses | Consulted very widely. A listing here is serious |
| Spamhaus DBL | Domains | Widely used for domains found in message bodies |
| SpamCop | IP addresses | Fed by user reports, and expires listings automatically |
| Barracuda | IP addresses | Used by Barracuda appliances, common in mid-sized firms |
| PSBL, WPBL, Lashback UBL, UCEPROTECT level 1, s5h | IP addresses | Smaller lists. One of these alone rarely moves delivery; several together is a signal |
| SURBL, NordSpam DBL | Domains | Link and sender domains, used by many spam filters |
Zone behavior as documented by each operator, checked September 2026. SORBS is not queried: it shut down in June 2024 and its zones no longer carry listings.
We query a short list of zones on purpose. Checkers that report a hundred or more lists include zones nobody consults, zones abandoned for years, and a few that list whole countries. A red row from a list no receiver queries is noise dressed as an alert.
Private scores come next. Gmail, Microsoft and Yahoo each keep their own reputation for your IP and domain, so watch Google Postmaster Tools and Microsoft SNDS alongside this page. Read how sender reputation is scored for what feeds those numbers.
What to do about a listing
Read the reason before you touch a removal form. Most lists publish a TXT record with a short explanation and a link, and that text usually names the behavior: a spam trap hit, a volume spike, or output from a hacked account.
Then find the cause. A sudden listing after a campaign points at the list you mailed. A listing on an IP you share with other tenants points at your host. A listing that keeps coming back after each removal means the traffic never stopped.
Only then request removal. Spamhaus and several others drop a listing on their own once the traffic stops, so patience costs nothing. If the cause was old addresses, our guide on how to remove spam traps covers the clean-up, and a verified list keeps the next campaign off these zones. ZapBounce gives every account 100 free credits a month, and paid credits never expire (see pricing).
Questions people ask
How do I check if my IP is on the Spamhaus blacklist?
Enter the sending IP in the checker above. ZapBounce queries Spamhaus ZEN, which combines the SBL, XBL and PBL lists, and shows the return code and reason text for any listing. For a domain, it queries the Spamhaus DBL instead.
What is a DNSBL?
A DNS blocklist is a zone that answers a DNS query for a reversed IP address or a domain. If the host is listed, the zone returns a code in 127.0.0.0/8 and usually a TXT record explaining why. Receiving mail servers query these zones during the SMTP conversation.
How do I get removed from the Spamhaus blacklist?
Fix the cause first, then use the removal page Spamhaus links from the listing. XBL and PBL entries have a self-service form on check.spamhaus.org. SBL listings are opened as tickets with the network owner. Requesting removal while the traffic continues gets the host relisted within days.
Does being on a blocklist mean my mail bounces?
Only at receivers that consult that list. Spamhaus ZEN is queried by a large share of mail servers, so a listing there is serious. A listing on one small zone that few receivers query rarely changes delivery on its own.
Can a competitor get me listed?
Not easily. Listings come from observed traffic and spam trap hits rather than complaints alone, so manufacturing one against a sender who behaves normally takes more effort than it is worth.
Clean the list before the next send
Dead addresses and recycled traps are what put a sender on these lists. ZapBounce removes the dead addresses before you send, and unknowns are never billed.