Is your IP or domain blacklisted?
We query 50 major spam and reputation blocklists, including Spamhaus, Barracuda, SpamCop and SURBL, in one click.
How the Blacklist Check Works
From the moment you submit an address to the verdict badge, every lookup follows the same six stages, with no manual steps on your side.
Input Detection
Your entry is classified automatically (IP versus domain) before anything else runs.
DNS Resolution
Domains are resolved to the A-record addresses they currently point at.
IP Zone Queries
Reverse lookups fan out across the major IP blocklists for every address involved.
Domain Zone Queries
SURBL and URIBL-style lookups question the name itself, not just the servers behind it.
Verdict Compilation
All responses roll up into a single listed / not-listed badge with the counts attached.
Remediation Pointers
Every listed zone arrives with a direct link to its own removal information.
One Query, Every Major Blocklist
A single submission fans out across every zone we track and returns one consolidated answer. These are the list families doing that work behind the badge.
Spamhaus Zen & DBL
Zen flags spam sources, hijacked servers and botnets by IP, while DBL catches domains used in spam by name. These are among the most referenced filtering sources around.
Barracuda & SpamCop
Appliance-driven and report-driven listings alike. SpamCop entries are short-lived records built from what recipients reported.
SURBL / URIBL
Body-focused lists that flag domains appearing inside spam messages, rather than the sending IPs that delivered them.
SORBS & DroneBL
Dynamic IP pools, open relays and botnet infrastructure: the technical backgrounds receivers refuse mail from outright.
Shared-Hosting Visibility
Neighbours shape a shared IP's reputation, so the verdict makes it obvious when someone else's behaviour is costing you.
Delist Guidance
A removal link surfaces for every list in the table, so a listing always comes with its way out one click away.
Two Senders, Two Very Different Verdicts
Both outcomes below are illustrative samples rather than live data; run the checker above to query the zones yourself.
198.51.100.24
- IP zones queried30
- Domain zones queried4
- Listings0
203.0.113.77
- SpamCopListed
- BackscattererListed
- First stepCheck for open relays
Why Blacklist Monitoring Matters
Receivers consult DNS blocklists on every incoming connection. When your IP or domain shows up on one, messages start landing in spam folders or bouncing, usually before you have any idea something went wrong.
Catch Reputation Damage Early
Surface listings while they are fresh, instead of learning about them from dropped opens and customer complaints.
Protect Revenue Sends
Campaigns reach inboxes instead of junk folders, protecting the income every delivery depends on.
Diagnose Fast
The verdict tells you exactly which list flagged you and on which address, so the investigation starts narrow.
Fix Root Causes
Removal links sit alongside authentication and list-hygiene guidance, so the fix targets the source rather than the symptom.
Four Teams, Four Reasons to Look
Pick a team to see where a blacklist check slots into its routine.
Weekly reputation routine
- List every IP your servers send from
- Check each IP against all zones
- Open delist pages for anything listed
- Re-run until every badge turns clean
Shared infrastructure watch
- Record the addresses your provider sends from
- Check them before major launches
- Compare results after provider or region changes
- Alert your email vendor early on any listing
Client takeover vetting
- Collect the client's sending domains
- Let the check resolve and query each one
- Note inherited listings and their likely causes
- Agree a remediation plan before go-live
Deliverability cliff triage
- Start the moment mail begins bouncing
- Feed in the IP your bounce logs point to
- Read the badges to identify offending zones
- Delist and patch the root cause
Listed? Here Is the Way Back
A listing is a setback with a known playbook: find the cause, clean it up, then ask each operator for review. This is how senders end up flagged, and how they get off again.
How senders end up listed
- A hacked website or mailbox quietly pumps out spam on your behalf.
- Bought or scraped recipient lists turn out to hold spam traps.
- Shared hosting neighbours misbehave and drag down the IP you both use.
- SPF, DKIM or DMARC is missing, leaving your mail unverified at receivers.
- Unverified recipient lists push bounce rates, and suspicion, upward.
Getting delisted
Fix the root cause before anything else. Operators relist repeat offenders faster and keep them listed longer, so a removal request without a fix rarely sticks. Then work through the delist link shown for each listed zone in the results table above.
- Spamhaus listings often expire on their own for low volumes of mail.
- SpamCop entries typically lapse about a day after the reports stop.
- Barracuda handles removals through a request form on its website.
Prevention checklist
- Authenticate your domain. Start with the SPF, DKIM and DMARC checker.
- Screen recipients through the bulk email checker before every campaign.
- Never buy or scrape email lists.
- Watch bounce rates after each send.
- Guard signup forms with captcha so bots cannot submit junk addresses.
The lists behind the verdict
Eight of the zones feeding the badge, and what each one watches for.
| Blocklist | What it tracks |
|---|---|
| Spamhaus Zen | Spam sources, hijacked servers and botnets. It is the most referenced list in mail filtering. |
| Barracuda | IPs sending spam through Barracuda appliances. |
| SpamCop | Reported spam sources, with short listings. |
| SORBS | Spam sources, open relays and dynamic IPs. |
| SURBL / URIBL | Domains appearing in spam message bodies rather than sending IPs. |
| Backscatterer | Servers sending bounce spam to innocent third parties. |
| DroneBL | Botnets and malware infrastructure. |
| Spamhaus DBL | Domains used in spam, checked by name instead of IP. |
When One Lookup Is Not Enough
This page runs single, browser-based blacklist lookups. Emails Checker verifies entire lists end to end; here is exactly where each one stops.
| Capability | Free CheckerThis page | Emails CheckerFull platform |
|---|---|---|
| Single-address lookups | Yes | Yes |
| Blocklist queries | 50 zones per lookup | Not part of verification plans |
| Bulk list verification | Not on this tool | CSV files of any size |
| Disposable detection | Not on this tool | Included |
| Full SMTP mailbox checks | Format & DNS only on this tool | Yes |
| Account required | No | 100 free credits on signup |