How It Works
Perform spam database checks in four steps
Enter IP or Domain
Type in your mail server IP address or domain name (e.g. mail.domain.com).
Resolve IP Target
We automatically query your domain's primary A record to discover target IPs.
Parallel DNSBL Scans
Our backend concurrently checks the reversed IP and domain against 10+ spam lists.
Detailed Audit Logs
Get listing category returns, reputation safety percentage dials, and delist links.
Audit Spam Blacklist Reputation
Enter your domain name or mail server IPv4 address to run scans against 10+ major DNSBL/RBL databases.
Why Use Our Blacklist Checker?
The fastest and most complete scanner to verify your email sender score and domain listings.
Parallel Scans Engine
Our server checks domains and IP addresses against 10+ reputable blacklists simultaneously, returning full audits in under 3 seconds.
Deep Domain & IP Lookup
Enter a domain and our utility resolves its A record, verifying both the resolved IP address and domain name against blocklists.
Actionable Delisting Help
We provide details on response codes returned by DNSBL servers and links to request removal from their database listings.
Trusted by Sysadmins & Postmasters
What professionals are saying about our spam blacklist checker
"This tool checked our server IP against all major databases in seconds, pointing out we were listed on SORBS. Fixed our mail queues immediately."
Marcus Aurel
IT Administrator
"The clean safety score makes client reporting very simple. I can quickly verify that their domain reputation is clean and healthy."
Laura Green
SEO Architect
"Great support for both domains and IPs. It resolved our domain A record and checked the underlying IP against RBLs instantly."
Steve Rogers
System Engineer
Latest Articles & Guides
Expert tips to repair domain reputations and request delistings
What is a DNSBL? Email Spam Blacklists Explained
Learn what DNS-based Blackhole Lists (DNSBLs) are, how they work, and how email providers use them to block spam messages.
How to Request Delisting from Spam Blacklists
Step-by-step guide to identifying listing reasons and submitting removal requests to Spamhaus, Barracuda, and SORBS.
Best Practices to Keep Your Mail Server IPs Off Blacklists
Discover crucial server configuration strategies, email authentication setups, and list hygiene habits to preserve your sender score.
Frequently Asked Questions
An email blacklist, or DNS-based Blackhole List (DNSBL), is a real-time database of IP addresses and domains that have been flagged as sources of spam, malware, or other network abuse.
IPs are listed when they send unsolicited bulk emails, hit spam trap honeypots, have misconfigured mail relays, or get infected by malware that sends spam emails automatically.
IP blacklists (like ZEN Spamhaus) block the physical server sending the mail. Domain blacklists (like Spamhaus DBL) target the domain name contained in the email headers or links.
First, solve the root issue (e.g. stop the spam source or secure your server). Then, lookup your IP on the blacklist's website and submit a removal/delisting request form. Most lists will remove clean IPs within hours.
Spamhaus PBL lists residential IP ranges that should not run public mail servers. If you are checking a home/residential internet connection, it is normal and expected to be listed on the PBL.