IP & Domain Blacklist Checker
Check any public IP or domain against major spam blacklists including Spamhaus, Barracuda, SpamCop, and SORBS to diagnose email reputation and deliverability problems.
Useful for
Email bounces, spam folder issues, and reputation checks
Checks
Major DNSBLs used in real mail filtering workflows
Good to know
A clean result helps, but mail setup still matters
Why Blacklist Status Matters for Canadian Businesses
If your sending IP is blacklisted, messages can be blocked, delayed, or routed to spam by providers like Google, Outlook, Bell, and Rogers. That can affect invoices, customer replies, transactional messages, and internal operational email.
For Canadian businesses, maintaining secure and reputable email infrastructure is part of basic operational hygiene. A blacklist listing can be an early warning sign of abuse, poor authentication, or a compromised system that needs immediate attention.
What is a DNSBL blacklist?
A DNSBL, sometimes called a blacklist or blocklist, is a real-time database used by mail systems to identify IPs or domains associated with spam, malware, phishing, or suspicious sending behaviour.
When a receiving mail server accepts an incoming message, it may query one or more DNSBLs to decide whether the sender should be trusted, filtered, delayed, or rejected. That is why blacklist status is often one of the first things to check when email delivery suddenly breaks.
Why did my IP get blacklisted?
The most common technical and reputation reasons an IP ends up on a DNSBL.
Compromised mailboxes
A stolen mailbox password can be enough to generate large volumes of spam from an otherwise legitimate mail server.
Shared infrastructure
On shared hosting or shared mail systems, another user on the same IP can damage the reputation for everyone else.
Compromised website or server
Malware, spam scripts, abused contact forms, or a hacked CMS can quietly send mail in the background until the IP gets listed.
Weak email DNS
Missing PTR, SPF, DKIM, or DMARC records can reduce trust and make deliverability problems much worse.
Mail server checklist after a blacklist hit
A practical checklist that makes this page more useful than just a yes or no lookup.
SPF record
Confirm your sending hosts are authorized in SPF and that there are no broken includes or syntax issues.
DKIM signing
Check that outbound mail is being signed correctly and that the selector record exists in DNS.
DMARC policy
Make sure DMARC is published and aligned so receivers can evaluate your domain properly.
Reverse DNS / PTR
The sending IP should resolve back to a valid hostname, ideally matching your mail server identity.
Outbound logs
Inspect queue spikes, strange recipients, sudden volume changes, and authentication events.
Forms and scripts
Audit website forms, plugins, and scripts that could be abused to send mail without your knowledge.
How to get delisted
Identify the cause
Review sending logs, account security, DNS records, forms, and server health to find out why the IP was listed.
Fix the problem fully
Secure compromised accounts, patch vulnerable apps, remove malware, and correct DNS or mail configuration issues.
Use the blacklist operator’s process
Each list has its own lookup and delisting system. Use the instructions for the specific service that flagged your IP.
Monitor after cleanup
Re-test the IP, watch logs for repeat abuse, and keep an eye on bounce messages and spam-folder performance.
Related tools for deeper troubleshooting
Good internal linking and genuinely useful follow-up checks for mail and DNS issues.
MX Lookup
Check where a domain receives email and verify mail routing records.
DNS Lookup
Inspect DNS records when diagnosing name resolution or mail configuration issues.
IP Lookup
Review ownership and network context for the IP you are troubleshooting.
WHOIS Lookup
Research domain registration details and related administrative data.
Frequently Asked Questions
What is a DNSBL?
A DNSBL, or Domain Name System Blackhole List, is a reputation database used by mail servers to identify IP addresses or domains associated with spam, malware, phishing, or abusive sending patterns.
Why is my IP address blacklisted?
The most common causes are compromised accounts, infected websites or servers, poor email list hygiene, weak authentication, missing reverse DNS, or shared infrastructure where another sender hurt the reputation of the IP.
How do I get my IP off a blacklist?
First fix the root cause. Secure accounts, patch software, review logs, stop the unwanted email flow, and correct DNS or mail authentication issues. Then follow the specific delisting process for the blacklist that listed your IP.
Does being blacklisted ruin my SEO?
Typical email blacklists do not directly affect search rankings. The main impact is on deliverability and sender reputation. Security-related browser or malware blacklists are a different issue and can affect user trust and traffic.
What is the difference between an IP blacklist and a domain blacklist?
An IP blacklist focuses on the sending server or network address. A domain blacklist targets the domain itself. In some cases, moving to a new host or IP will not solve the problem if the domain reputation is the real issue.
How long does delisting take?
That depends on the blacklist. Some remove entries automatically after the abusive activity stops, while others require a manual review or formal request. Repeat issues can slow or prevent removal.