Email Blacklist Checker
Enter a domain to check against 8 domain blacklists, or an IP to check against 18 IP blacklists. Direct delist links included.
Enter a domain (e.g., yourcompany.com) or an IPv4 address. We'll resolve A and MX records automatically.
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Blacklist Results
| Blacklist | Status | Description |
|---|
Recommendations
What is an Email Blacklist?
An email blacklist (also called a DNSBL, or DNS-based Blackhole List) is a real-time database of IP addresses and domains that have been identified as sources of spam, malware, or other abusive email activity. Blacklists are maintained by independent organizations that collect reports, analyze email traffic patterns, and use automated spam traps to identify bad senders.
When your IP or domain appears on a blacklist, receiving mail servers may reject your emails outright or route them to the spam folder. This can have a devastating effect on your email deliverability, since major mailbox providers like Gmail, Outlook, and Yahoo all consult one or more blacklists as part of their filtering decisions. Even a single listing on a widely used blacklist like Spamhaus can cause delivery rates to drop dramatically.
Blacklists serve an important purpose in the email ecosystem: they help protect users from unwanted and dangerous messages. However, legitimate senders can end up on blacklists too, often due to a compromised account, a poorly maintained mailing list, or a shared IP address that was abused by another sender. Regular monitoring is essential to catch listings early and resolve them before they cause lasting damage to your sender reputation.
How Email Blacklists Work
Email blacklists use the Domain Name System (DNS) as their query mechanism, which is why they are called DNS-based Blackhole Lists. When a mail server receives an incoming connection, it can check the connecting IP address against one or more blacklists by performing a simple DNS lookup. This happens in real-time during the SMTP transaction, before the message is even accepted.
The DNSBL Lookup Process
To check whether an IP address is listed, the receiving server reverses the octets of the IP and appends the blacklist's domain. For example, to check IP 192.0.2.1 against Spamhaus ZEN, the server queries 1.2.0.192.zen.spamhaus.org as an A record. If the blacklist returns a result (typically an address in the 127.0.0.x range), the IP is listed. If the query returns NXDOMAIN (no record found), the IP is clean on that list.
What Happens During SMTP
When a sending server opens an SMTP connection, the receiving server sees the connecting IP address. Before accepting the message, it can query multiple blacklists simultaneously. If the IP is found on one or more lists, the server may reject the connection with a 5xx error (permanent rejection), return a 4xx error (temporary rejection, try again later), or accept the message but increase its spam score, making it more likely to land in the junk folder.
Domain-Based Blacklists
Some blacklists, like Spamhaus DBL, SURBL, and URIBL, operate on domain names rather than IP addresses. Instead of reversing an IP, the receiving server queries the sending domain directly against the blacklist. For example, checking example.com.dbl.spamhaus.org. Domain blacklists catch bad actors who rotate through different IP addresses but continue using the same domain in their messages. This tool checks your domain against 8 domain-based blocklists in addition to checking your IPs against 18 IP-based lists.
All 26 Blacklists We Check
This tool checks your IP against 18 IP-based blocklists and your domain against 8 domain-based blocklists. When a listing is found, we show you exactly what it means and step-by-step instructions to get delisted.
IP Blacklists (18)
| Blacklist | What It Tracks |
|---|---|
| Spamhaus ZEN | The #1 blocklist. Combines all Spamhaus IP lists (SBL, XBL, PBL, CSS). Used by the majority of mail providers worldwide. |
| Barracuda (IP) | Spam sources detected by Barracuda Networks' global network of email security products. |
| CBL | Hacked or infected machines sending spam. Feeds into Spamhaus ZEN, so a CBL listing means you're effectively on Spamhaus too. |
| SpamCop | Crowd-sourced spam reports powered by Cisco Talos. Listings auto-expire within 24-48 hours. |
| Blocklist.de | IPs reported for attacks, spam, or abuse by fail2ban users across thousands of servers. |
| DroneBL | Compromised machines, open proxies, and botnets. Community-driven with type codes explaining the issue. |
| Hostkarma | Reputation-based IP scoring with a color system (white/black/brown/yellow). |
| Lashback UBL | IPs that send to addresses harvested from suppression/unsubscribe lists (a CAN-SPAM violation). |
| Mailspike | Real-time IP reputation from a global spam trap network. |
| Nordspam (IP) | Nordic-focused spam source detection for Scandinavian email systems. |
| SPFBL | Brazilian anti-spam DNS blocklist combining spam detection with SPF validation. |
| SpamRATS NoPtr | IPs without proper reverse DNS (PTR) records. |
| SpamRATS DYNA | Dynamic/residential IPs with generic-looking reverse DNS names. |
| SpamRATS SPAM | IPs caught sending spam to SpamRATS trap addresses. |
| PSBL | Passive spam detection via distributed spam traps. Listings auto-expire. |
| Backscatterer | IPs sending bounces to forged sender addresses (backscatter). |
| UCEPROTECT L1 | Individual IPs sending unsolicited email. Auto-clears after 7 days. |
| 0Spam | Fully automated, Canadian-operated real-time spam detection. |
Domain Blacklists (8)
| Blacklist | What It Tracks |
|---|---|
| Spamhaus DBL | The #1 domain blocklist. Tracks domains used in spam, phishing, and malware regardless of sending IP. |
| Barracuda (Domain) | Domain reputation by Barracuda Networks' email security products. |
| SURBL Multi | Domains found in spam message bodies (URI blocklist). Widely used by SpamAssassin. |
| URIBL Black | High-confidence spam domain URI blocklist. Most impactful URIBL sub-list. |
| URIBL Multi | Multi-source URI domain blocklist combining multiple detection methods. |
| URIBL Red | Domains from known spam redirectors, phishing, and malware distribution. |
| Nordspam (Domain) | Nordic-focused domain spam detection for Scandinavian email systems. |
| URIBL Grey | Domains found in spam but not yet confirmed. More false positives than Black. |
How to Get Delisted
If your IP or domain appears on a blacklist, follow these steps to get removed and prevent future listings:
1. Identify the Root Cause
Before requesting removal, you need to understand why you were listed. Common causes include sending to purchased or scraped email lists, having a compromised account or server, running an open relay, lacking proper authentication (SPF, DKIM, DMARC), or sharing an IP with another sender who was spamming. Fix the underlying problem first, or you will get listed again immediately after removal.
2. Fix the Problem
Clean your mailing list by removing bounced addresses, unsubscribed users, and spam traps. Secure your server by patching vulnerabilities, changing compromised passwords, and closing open relays. Set up proper email authentication records. If you are on a shared IP, contact your email service provider to request a move to a cleaner IP or a dedicated IP address.
3. Submit a Delisting Request
Each blacklist has its own removal process. Some, like SpamCop and PSBL, automatically remove listings after the spam stops (usually 24-48 hours). Others, like Spamhaus and Barracuda, require you to visit their website and submit a formal removal request. Our tool provides direct links to each blacklist's delisting page. When submitting a request, be honest about what happened and what steps you took to fix it.
4. Monitor Going Forward
After getting delisted, monitor your IPs and domains regularly. Set up a recurring check (weekly at minimum) to catch new listings early. Consider using a dedicated monitoring service or running this tool periodically to stay ahead of any issues.
Preventing Blacklisting
The best approach to blacklists is prevention. Follow these best practices to minimize your risk of getting listed:
Maintain Clean Email Lists
Never purchase or scrape email addresses. Use confirmed opt-in (double opt-in) for all new subscribers. Remove bounced addresses immediately and honor unsubscribe requests promptly. Regularly clean your list by removing inactive subscribers who have not engaged in 6-12 months, as these old addresses may have been converted to spam traps.
Authenticate Your Email
Implement all three major authentication protocols: SPF to declare which servers can send as your domain, DKIM to cryptographically sign your messages, and DMARC to tie them together with a policy. Proper authentication proves you are a legitimate sender and protects your domain from being spoofed by others.
Configure Your Infrastructure
Set up proper reverse DNS (PTR records) for all sending IPs. Make sure your server is not configured as an open relay. Use TLS encryption for all SMTP connections. If you use a shared IP for sending, consider moving to a dedicated IP once your volume justifies it, so you are not affected by other senders' behavior.
Monitor Sending Behavior
Watch your bounce rates, complaint rates, and engagement metrics closely. A sudden spike in bounces or complaints is often a warning sign that a blacklisting may follow. Most email service providers offer dashboards with these metrics. Aim to keep your complaint rate below 0.1% and your bounce rate below 2%.
Warm Up New IPs
If you start sending from a new IP address, gradually increase your sending volume over 2-4 weeks. Start with your most engaged recipients and slowly ramp up. Sending a large volume from a brand new IP with no reputation is a common trigger for blacklisting.
Frequently Asked Questions
How often should I check my blacklist status?
At minimum, check weekly. If you send high volumes of email (over 10,000 per day) or have experienced blacklisting in the past, daily monitoring is recommended. Many deliverability issues start with a blacklisting that goes unnoticed for days, causing significant damage to your sender reputation before you even realize there is a problem. Set a recurring reminder or use an automated monitoring solution to stay on top of it.
Can I be blacklisted even if I don't send spam?
Yes. There are several scenarios where legitimate senders end up on blacklists. If you use a shared IP address (common with most email service providers), another sender on the same IP may have triggered a listing that affects you. A compromised user account in your organization could send spam without your knowledge. Sending to a very old or purchased list often contains spam traps, which are email addresses specifically set up by blacklist operators to catch senders who do not follow best practices. Even a misconfigured mail server (such as an open relay) can get listed.
How long does it take to get delisted?
It varies significantly by blacklist. Some lists like SpamCop and PSBL automatically expire listings within 24-48 hours once the spam stops. Spamhaus typically processes removal requests within a few hours if the underlying issue has been resolved. Barracuda can take 12-24 hours. UCEPROTECT auto-clears after 7 days. The key factor is whether you have actually fixed the problem. If the issue persists, you will be re-listed immediately even if you successfully get removed.
Does being on one blacklist affect all my email?
Not all blacklists are weighted equally. Spamhaus is the most impactful because it is used by the vast majority of mail servers worldwide. A listing there will cause widespread delivery failures. Smaller or regional lists like Nordspam or DroneBL are used by fewer providers, so the impact is more limited. However, being on any blacklist is a negative signal. Major providers like Gmail and Microsoft use their own internal reputation systems alongside public blacklists, so a single listing may only be one factor in their filtering decision.
What is the difference between an IP blacklist and a domain blacklist?
IP blacklists track the numerical IP addresses of servers that send spam. When you send an email, the receiving server sees your IP address and can check it against these lists. Domain blacklists track domain names that appear in spam messages, regardless of what IP sent the message. This is important because sophisticated spammers often rotate through many IP addresses but reuse the same domain. Domain blacklists like Spamhaus DBL catch these senders by flagging the domain itself. Both types of blacklists play a role in email filtering, which is why this tool checks your domain against DBL in addition to checking your IPs against the IP-based lists.