IP Blacklist Check

Checks an IP against 14 DNSBLs (Spamhaus, Barracuda, SpamCop and more) and a domain against 3 domain blocklists — for a domain, both the website and mail server IPs.

216.73.217.25

Checks run: 14

listings

no answer

Not listed on any of the lists that answered. Some lists did not answer — their result is unknown, not "clean".

Checked IP: 216.73.217.25

List	Zone	Status	Details
Spamhaus ZENkey list SBL + XBL + CSS + PBL — the most influential list	zen.spamhaus.org	No answer	the list did not confirm its own test address — down or blocking us
Barracuda BRBLkey list Used by Barracuda gateways at thousands of companies	b.barracudacentral.org	Not listed
SpamCopkey list User spam reports; listings expire on their own in ~24 h	bl.spamcop.net	Not listed
PSBL Spam traps; self-service removal	psbl.surriel.com	Not listed
Mailspike Sender reputation	bl.mailspike.net	Not listed
UCEPROTECT L1 Single IPs only; listings expire after 7 days	dnsbl-1.uceprotect.net	Not listed
DroneBL Bots and open proxies; matters mostly for IRC	dnsbl.dronebl.org	Not listed
blocklist.de Attacks: SSH/mail brute force, scanning	bl.blocklist.de	Not listed
InterServer Spam and attacks seen by the InterServer host	rbl.interserver.net	Not listed
s5h.net Small private trap-based list	all.s5h.net	Not listed
SPFBL Brazilian list, common in Latin America	dnsbl.spfbl.net	No answer	DNS error (SERVFAIL) — the list's servers are unreachable
NordSpam Nordic trap-based list	bl.nordspam.com	Not listed
Spam Eating Monkey Spam traps, listings expire automatically	bl.spameatingmonkey.net	Not listed
GBUdb Truncate Only IPs that send almost nothing but spam	truncate.gbudb.net	Not listed

How we check: every list is first queried with the test address 127.0.0.2 (must be listed) and 127.0.0.1 (must not be). A list that fails this test shows "No answer", never "clean". Spamhaus refusal codes (127.255.255.x) count as errors, not listings. Check time: 0.2 s.

How to check if an IP or domain is blacklisted

The tool checks an IP address against 14 DNSBLs (Spamhaus ZEN, Barracuda, SpamCop, PSBL, Mailspike, UCEPROTECT and more) and a domain against the Spamhaus DBL, SURBL and URIBL domain lists. For a domain it checks both the website IPs and the mail server IPs from MX. Every list is first tested with a control address, so a list that is down shows "no answer" instead of a false "clean". Listings come with the return code, the reason from the TXT record and a delisting link.

17 IP lists and 3 domain lists, queried in parallel

IPv4, IPv6 and domains (website IPs + mail IPs from MX)

Honest statuses: "no answer" is never shown as "clean"

Listing reason and delisting links

How to Use

Enter an IP address (IPv4 or IPv6) or a domain
Wait while all lists are queried in parallel — usually 1–4 seconds
Start with the key lists; for any listing, read the reason and follow the delisting link

FAQ

A DNSBL (or RBL) is a list of IP addresses seen sending spam, infected or attacking; mail servers look it up over DNS for every incoming message. An address usually lands there after mail hits spam traps, recipients complain, a machine on the network gets infected, a mailbox is hacked or a relay is left open. Sometimes it is listed simply because it is dynamic or has no PTR record.

For email, Spamhaus comes first (ZEN and the DBL domain list), followed by Barracuda and SpamCop: many corporate and hosting mail servers use them. Listings on small lists (UCEPROTECT, DroneBL, s5h and the like) rarely affect delivery to Gmail or Outlook, which rely on their own reputation filters — and can reject mail even when you are on no DNSBL at all.

Fix the cause first: find the infected machine or hacked mailbox, close any open relay, stop unsolicited sending, and set up PTR, SPF, DKIM and DMARC. Then submit a request on the list's site — the link is in the row with the listing. SpamCop and many small lists expire entries on their own within 1–7 days; if the cause remains, the address will be listed again.

The list did not answer in time, returned an error or failed to confirm its own test address 127.0.0.2. For example, Spamhaus does not serve queries made through public DNS resolvers and answers them with 127.255.255.254 — many online checkers wrongly show that as "listed", while Google's resolver returns "not found", which looks like "clean". In those cases we query the list's own servers directly, and if that fails too we say "no answer".

Not directly: Google does not use DNSBLs for ranking, and shared hosting IPs are used by hundreds of sites. Domain lists (Spamhaus DBL, SURBL) matter indirectly: links to a listed domain get stripped in email and messengers, and antivirus and browser filters may block it. A domain listing usually means spam or a compromise, so scan the site for infection.

How to check if an IP address or domain is blacklisted

Enter an IPv4 or IPv6 address or a domain. An IP is checked against 14 DNSBLs — lists of addresses seen sending spam, infected or attacking. For a domain the tool runs three checks at once: the website IPs (A/AAAA records), the mail server IPs from MX, and the domain itself on the Spamhaus DBL, SURBL and URIBL domain lists, which catch domains that appear in links in spam and phishing.

Keep in mind that mail often does not leave from the MX address. If Google Workspace, Microsoft 365 or an email service provider sends your mail, their IPs are the ones to check. You can find the sending IP in the Received headers of any delivered message: open "Show original" and look for the earliest Received: from … [203.0.113.5] line outside your own network.

How to read the results

Status	Meaning	What to do
Listed	The list returned a listing code (127.0.0.x). Next to it: the code, the reason from the TXT record and a delisting link	On a key list, find the cause now; on a minor list, act if you send mail from this IP
Not listed	The list answered and the address is not on it	Nothing
PBL	Spamhaus PBL: the address is in a range its ISP says should not send mail directly (usually residential or dynamic)	Not a spam listing. For your own mail server, remove the IP from the PBL on the Spamhaus site or relay through your provider
No answer	The list timed out, returned an error or failed the test with the control address 127.0.0.2	Result unknown — not "clean". Try again later
IPv4 only	The list does not accept IPv6 addresses	IPv6 is currently covered by Spamhaus ZEN and DroneBL

Which blacklists actually matter

There are hundreds of public DNSBLs, but only a few noticeably hurt email delivery. Gmail, Outlook and Yahoo mostly rely on their own sender reputation; DNSBLs are used by corporate mail servers, hosting companies and spam filters such as SpamAssassin and Rspamd.

List	What it catches	How to get off it
Spamhaus ZEN (SBL, CSS, XBL, PBL)	Spam operations, infected machines and botnets, bad ranges	Fix the cause, then request removal at check.spamhaus.org. XBL and CSS usually clear without a manual request
Spamhaus DBL	Domains seen in spam, phishing and malware	Clean the site and file a request at check.spamhaus.org
Barracuda BRBL	IPs sending spam into Barracuda customers' networks	The removal-request form at barracudacentral.org
SpamCop	User reports and spam traps	Expires on its own about a day after the spam stops
UCEPROTECT L1	Individual IPs that hit traps	Expires after 7 days without new spam; the list charges for express removal — you do not have to pay
PSBL, Mailspike, DroneBL and others	Spam traps, missing PTR, residential addresses	Self-service removal on the list's site, or wait

We leave out dead lists that many online checkers still query: SORBS shut down in 2024, NJABL and WPBL no longer work, and the AHBL zone answers "listed" for every address. We also skip UCEPROTECT levels 2 and 3, which block entire provider networks because of their neighbours.

Why online blacklist checkers disagree

DNSBLs are queried over DNS, and the answer depends on which resolver asks. Spamhaus does not serve public resolvers: through Cloudflare's 1.1.1.1 it returns 127.255.255.254, while Google's 8.8.8.8 returns "domain not found". Many services show the first as "listed" and the second as "clean", although both mean "the check did not happen". That is why this tool first tests every list with control addresses: 127.0.0.2 must be listed and 127.0.0.1 must not. If a list does not answer our resolver (Spamhaus does this on free access), you see "No answer" with a link to check the address on the list's own site.

To check an IP by hand, reverse its octets and append the list's zone:

# IP 203.0.113.5 → 5.113.0.203
dig +short 5.113.0.203.zen.spamhaus.org
dig +short TXT 5.113.0.203.zen.spamhaus.org   # listing reason

# A domain in Spamhaus DBL
dig +short example.com.dbl.spamhaus.org

# Test the list itself: the answer must be 127.0.0.x
dig +short 2.0.0.127.zen.spamhaus.org

Spamhaus answer	Meaning
127.0.0.2 / 127.0.0.9	SBL / SBL DROP — spam operation or hijacked range
127.0.0.3	SBL CSS — poor sending reputation
127.0.0.4–7	XBL — infected machine, bot or open proxy
127.0.0.10 / 127.0.0.11	PBL — should not send mail directly
127.0.1.x	DBL — domain listed (2 spam, 4 phishing, 5 malware)
127.255.255.252 / 254 / 255	Error: malformed query / public resolver / rate limit. Not a listing

How to remove your IP from a blacklist

Find the cause. Most often it is an infected computer on the office network, a hacked mailbox (the password was guessed and spam goes out through your SMTP), an open relay, spam through a website form, or mailing to a bought list.
Close it. Change passwords, rate-limit outgoing mail, update the CMS and plugins, remove the infection.
Fix your mail DNS. The IP's PTR record should point to the server name, and that name back to the IP (check it with reverse DNS). Set up SPF, DKIM and DMARC, and verify your MX records.
Request delisting using the "Delist" link in the listing row. If the cause is still there, the address will be listed again quickly, and the next removal will be harder.
On shared hosting the address is shared and a neighbour may be to blame. Contact your host, or send mail through a separate service with its own reputation.

Blacklists and SEO

Google does not use DNSBLs for ranking, and a shared hosting IP is used by hundreds of sites. You can see who shares an address with Reverse IP Lookup and who owns the network with ASN lookup. Domain lists matter indirectly: links to a domain on Spamhaus DBL or SURBL get stripped in email and messengers, and antivirus tools block it. A domain listing almost always means spam or a compromise — scan the site with the website security scanner.