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Free email blacklist checker
Check whether a domain, an IP address or an email address is on the blocklists mail servers query before accepting a message. Every listing links to the operator's own removal page, and every list that could not be reached is named rather than counted as a pass.
Ungated · no email required · unlimited checks
In short
- This is a free, ungated email blacklist checker from SmartReach.io. It looks up a domain, an IPv4 address or an email address in the DNS blocklists that receiving mail servers consult before accepting a message, and reports which lists it appears on. An email address is reduced to its domain.
- A domain is checked against the URI blocklists that govern whether links to it are accepted, currently SURBL and URIBL. The addresses behind the domain, taken from its MX and A records, are checked against the address blocklists: SpamCop, Barracuda, UCEPROTECT Level 1, SPFBL, Mailspike and blocklist.de.
- Spamhaus ZEN and Spamhaus DBL are reported as NOT CHECKED rather than as clean. Spamhaus answers NXDOMAIN to lookups arriving through a public DNS resolver, and that response is indistinguishable from a genuine not-listed result, so any checker treating it as a pass shows a clean Spamhaus result for every domain it is asked about.
- A list count is not a measure of coverage. Some widely advertised blocklists have shut down entirely, and a dead zone returns a clean answer forever. This tool checks a small set whose answers it can verify and states which lists it reached on each run.
- Not every answer from a blocklist is a listing. URIBL returns 127.0.0.1 for domains on its whitelist, and SPFBL answers on a reputation scale where only 127.0.0.2 is a block, so both are interpreted rather than counted as hits.
- A clean result is not a deliverability verdict. Blocklists are one input among several, and a domain on none of them can still land in spam through weak authentication, a cold sending domain, a high complaint rate or low engagement.
A domain is checked against the URI blocklists that govern links to it, and the addresses behind it are checked against the address blocklists. An email address is reduced to its domain. IPv6 addresses are not supported yet. ·
What this blacklist checker does
An email blacklist checker tells you whether a domain, an IP address or an email address is on the blocklists mail servers consult before accepting a message, because a listing is one of the few deliverability faults that stops mail outright rather than filtering it. This one checks the domain against the URI blocklists that govern links to it, resolves the addresses behind the domain and checks those against the address blocklists, reports the network that owns each address, and links the operator’s own removal page for every listing it finds. It is built by SmartReach.io, a cold email software that runs email, LinkedIn, calls and WhatsApp from one sequence. It is free and ungated, with no signup and no limit on the number of checks.
Why a listing is different
What happens when your domain is on a blacklist?
Your mail stops arriving rather than landing in spam. A blocklist hit on a list the receiver trusts produces a rejection during the SMTP conversation, so the message is never delivered anywhere and the sender gets a bounce naming the list. The free blacklist checker from SmartReach.io reports which lists a domain is on and links the removal page for each one.
A listing bounces mail, it does not filter it
Most deliverability problems move mail to a spam folder, where it can still be found. A blocklist hit on a list the receiver trusts produces a rejection at the SMTP conversation, so the message never arrives anywhere and the sender gets a bounce naming the list.
The domain outlives the address
A shared sending address can be left behind by switching provider. A domain listing follows the domain everywhere it sends and everywhere it is linked from, and it is the asset a sender actually owns.
Links get you listed too
URI blocklists catalogue the domains that appear as links inside unsolicited mail, not the servers that sent it. A domain can be listed because of where it was linked from, which is why a clean sending record is not on its own a defence.
Delisting is slower than listing
Automated listings can appear within hours of a volume spike. Removal is a request to an operator, granted at their discretion, and one made while the cause is still live is usually reversed.
One listing can affect mail you did not send
Receivers apply a domain listing to every message carrying that domain, including transactional mail, password resets and invoices sent from an entirely different system. A campaign problem becomes a billing problem the same day.
Nobody tells you when it happens
There is no notification. The first sign is usually a bounce message quoting a list, or a reply rate that halves for no visible reason, which is why the check is worth running before a campaign rather than after one goes quiet.
Checking
How do I check if my domain is blacklisted?
Three ways, and they answer different questions. The free email blacklist checker from SmartReach.io above is the only one of the three that tells you which specific list has you, which is what a removal request needs. The other two are worth knowing because they catch things a lookup cannot.
- 1
Look the domain up in the blocklists directly
Enter the domain above. It is checked against the URI blocklists that decide whether links to it are accepted, and the addresses behind it are checked against the address blocklists. This is the fastest answer and the only one that tells you which specific list has you, which is what a removal request needs.
- 2
Read the bounce message, which names the list
A rejection caused by a blocklist almost always says so in the SMTP response, quoting the list and often a lookup URL. If mail is bouncing rather than landing in spam, the bounce text is the most direct evidence you have, and it names the list without any tool at all.
- 3
Check your reputation with the mailbox providers
Google Postmaster Tools reports domain and IP reputation for mail you send to Gmail, and Microsoft SNDS does the equivalent for Outlook. Neither is a blocklist and neither replaces this check, but a domain sliding from high to low reputation there is often the warning that precedes a listing.
If mail is landing in spam rather than bouncing, a blocklist is usually not the cause. Start with the records receivers authenticate against, using the SPF, DKIM and DMARC checker, or read every record on the domain with the DNS record checker.
Two kinds of list
What is the difference between an IP blacklist and a domain blacklist?
An address blocklist lists the server a message came from. A domain blocklist lists the name that appeared as a link inside it. They are populated by different evidence and they fail in different ways, so SmartReach.io checks both on every domain rather than reporting one and calling it a verdict.
Address blocklists catalogue the server
They list the IP address a message was transmitted from, on the behaviour of that address: spam-trap hits, a volume spike, a compromised host. On shared sending infrastructure the address is your provider’s and its reputation is shared with every other sender on it, which is why a listing there is often not yours to fix.
Domain blocklists catalogue the name
URI blocklists list the domains that appear as LINKS inside unsolicited mail, not the servers that sent it. A domain can be listed for where it was linked from, by a campaign somebody else sent, while every address it sends from stays clean. This is the listing a sender owns, because the domain is the asset they own.
They fail in different ways, so both are checked
An address listing usually stops mail from one server while the domain keeps working elsewhere. A domain listing follows the domain to every server it ever sends from, and to every message that links to it. Checking one and not the other is how a sender concludes they are clean while half of their mail is being rejected.
Reading the result
What do the blacklist check results mean?
Five states, and the difference between two of them is the whole point. Not listed is an answer from a list that responded. Not checked is the absence of an answer, and the free blacklist checker from SmartReach.io never renders it as a pass.
The list answered and your domain or address is on it. Receivers consulting that list will reject or filter your mail. The operator’s own removal page is linked beside it, because that is the only place a delisting can be requested.
The list answered and does not have you. This is a real answer from a list that responded, which is the distinction that matters against the state below.
The list answered that it holds your domain on a whitelist, which is a stronger result than merely being absent from its blocklist. URIBL does this for domains it considers established.
The list answered with a reputation code rather than a block. It is not a listing and receivers do not reject on it, so it is reported separately rather than counted among your listings.
No usable answer was available, so no verdict is given. Spamhaus is permanently in this state because it returns NXDOMAIN to lookups from public resolvers, and that response cannot be told apart from a genuine pass. Treating it as clean is what produces a false all-clear, so it is left blank and linked instead.
Removal
How do I get my domain removed from a blacklist?
In five steps, and the order is not optional. There is no central delisting: each operator runs its own process, and a removal granted while the cause is still live is reversed within days.
- 1
Find the cause before you ask for anything
A delisting granted while the source is still sending is reversed within days, and repeated requests make the next one slower. Look at what changed shortly before the listing appeared: a bought or scraped list, a volume jump on a new sending domain, a compromised mailbox, or a form with no confirmation step.
- 2
Stop the sending that caused it
Pause the campaign or the mailbox involved. If a mailbox was compromised, change its password and revoke its app passwords and OAuth grants. If the cause was list quality, verify the addresses before you send to them again rather than after.
- 3
Fix the authentication the operator will look at
Most operators check whether the domain publishes SPF, DKIM and DMARC before granting a removal, because a domain that cannot be authenticated cannot be held responsible for its own mail. Publish all three and confirm they resolve.
- 4
Submit the removal request to each list separately
There is no central delisting. Each operator runs its own process and its own form, linked from every listing in the results above. Some remove automatically after a quiet period, some review by hand, and none of them are obliged to remove you at all.
- 5
Re-check, and expect the answer to lag
Removal propagates on the list’s own schedule, and receivers cache blocklist answers for their own TTLs on top of that. Re-run the check here after a day rather than after an hour, and resume sending gradually rather than at the volume that caused the listing.
Causes
Why did my domain get blacklisted?
Almost always because of something that changed shortly before the listing appeared. These are the six causes behind most listings on a sending domain, and the last two are the ones senders most often rule out too early.
Sending to addresses that do not exist
A high bounce rate is the clearest signal of a bought, scraped or stale list, and it is the one most operators weight heaviest. Verifying addresses before a campaign is the single change that prevents the most listings.
Volume from a domain with no history
A new sending domain going from nothing to hundreds of messages a day looks exactly like a disposable spam domain, because that is what disposable spam domains do. Warming the domain first is what separates the two.
A spam trap in the list
Trap addresses are seeded specifically to catch senders who did not collect their contacts, and some are recycled from addresses that were abandoned years ago. Hitting one is often enough on its own.
A compromised mailbox
A stolen password turns a legitimate mailbox into a spam source, and the listing arrives before anyone notices the sending. This is the cause most often missed, because the sender is looking at their campaigns rather than at their accounts.
Shared infrastructure someone else abused
On a shared sending address, another sender’s behaviour can list the address you send from. This is why the results here name the network that owns each address: a listing on your provider’s range is theirs to resolve, not yours.
Where your links point
URI blocklists catalogue the domains that appear as links inside unsolicited mail, not the servers that sent it. A domain can be listed for being linked from a campaign somebody else sent.
Coverage, stated honestly
Which blacklists does this tool check?
8 lists are queried and answered on the last review, and 2 are reported as not checked because they refuse lookups from public resolvers. The category advertises counts in the hundreds; a count says nothing about whether each answer is real. Those totals are also padded with zones that are not blocklists at all, such as bogon and routing-information lists, which no receiver rejects mail on. None are counted here.
| List | Checks | What it catalogues | Status |
|---|---|---|---|
| SURBL | Domains | Domains seen in spam, phishing, malware and abuse reports. | Queried |
| URIBL | Domains | Domains appearing as links in unsolicited mail. | Queried |
| Spamhaus DBL | Domains | The most widely deployed domain blocklist in email filtering. | not checked |
| SpamCop | Addresses | Addresses reported by SpamCop users for sending unsolicited mail. | Queried |
| Barracuda | Addresses | Barracuda Central reputation data, used across their mail gateways. | Queried |
| UCEPROTECT Level 1 | Addresses | Single addresses caught sending to UCEPROTECT spam traps. | Queried |
| SPFBL | Addresses | Reputation built from sender behaviour and SPF alignment. | Queried |
| Mailspike | Addresses | Reputation scoring from a large mail-flow sample. | Queried |
| blocklist.de | Addresses | Addresses reported for attacks on mail, SSH and web services. | Queried |
| Spamhaus ZEN | Addresses | SBL, XBL and PBL combined. The reference address blocklist. | not checked |
What this check cannot tell you
Can a blacklist checker prove my email will be delivered?
No. A clean result means these lists do not have you, which is a floor rather than a verdict. What follows is what this check cannot see, stated plainly, because a checker that hides its limits is the one that hands you a false all-clear.
Two lists here are reported as unchecked, on purpose
Spamhaus ZEN and Spamhaus DBL answer NXDOMAIN to queries arriving through a public DNS resolver, and that response is identical to a genuine "not listed". They are the most consequential lists in email, so reporting a guess as a pass would be the single most misleading thing this page could do. They are named, marked unchecked, and linked to Spamhaus’s own lookup instead.
A clean result is not a deliverability verdict
Blocklists are one input among several. A domain absent from every list here can still land in spam through poor authentication, a cold sending domain, a high complaint rate or low engagement. Nothing on this page measures those, and a checker implying otherwise would be selling a false all-clear.
A list count is not a quality measure
Querying two hundred zones is easy and mostly meaningless: many are defunct, several are operated by one person, and a few list entire address ranges on principle. This page checks a small set whose answers can be verified, and says which ones it reached on each run.
Only the addresses DNS can show are checked
A domain’s MX records name its inbound servers and its A records name its website. Neither is necessarily the address your campaigns send from, which for most senders belongs to their email provider and is not published anywhere in their DNS.
Once you know you are listed
Which records cause a blacklisting?
A listing is a symptom. The causes that live in DNS are a domain sending without authentication, a mail route pointing somewhere it should not, and records that contradict each other. These four tools read the records a delisting request will ask you to have fixed first.
Every record, and what they do to each other
DNS Record Checker
Read every DNS record on a domain at once, with the mail records checked against six independent resolvers, and find the faults that only exist in the combination: a CNAME voiding the MX beside it, a mail host with no address, two SPF records cancelling out.
What it looks like
MX 10 mail.example.com · TTL 300 · 6 resolvers agree
Which servers may send as you
SPF Checker
SPF lists the servers allowed to send mail for your domain. Check that yours is published, resolves, and stays under the ten-lookup limit that silently breaks it.
What it looks like
v=spf1 include:_spf.google.com ~all
Proof the message is really yours
DKIM Checker
DKIM signs every message with a key only you hold. Check that the public key is published, parses, is not revoked, and is long enough to be trusted.
What it looks like
v=DKIM1; k=rsa; p=MIIBIjANBgkq…
What happens when a check fails
DMARC Checker
DMARC tells receivers whether to quarantine or reject mail that fails SPF and DKIM, and where to send the reports. Check your policy, alignment and reporting address.
What it looks like
v=DMARC1; p=reject; pct=100
Each list is operated independently and each runs its own removal process, linked from its name in the table above and from every listing in the results. Spamhaus is reported as not checked because it refuses lookups through public resolvers; look your domain up directly at check.spamhaus.org. Last reviewed . The check is free and ungated, and what you enter is not stored or logged.
FREQUENTLY ASKED QUESTIONS
Blacklist questions, answered
The cheapest delisting is the one you never need.
Listings follow bounced sends, cold domains and volume spikes. SmartReach.io is a cold email software that runs email, LinkedIn, calls and WhatsApp from one sequence, with no per-seat pricing. It verifies every address before a campaign sends, warms and rotates the sending mailboxes, and pauses an inbox when its bounce rate crosses the threshold you set.