How to Check if Your Domain Is Blacklisted and How to Fix It
Why Domain Blacklisting Matters
Imagine spending months building your online presence, only to find that your emails land in spam folders and your website is flagged as unsafe. That's exactly what happens when your domain gets blacklisted. Email providers like Gmail, Outlook, and Yahoo, as well as security companies like Spamhaus and SURBL, maintain lists of domains and IP addresses known for sending spam or hosting malware.
If your domain appears on one of these lists, your legitimate emails bounce or get filtered, your site may display a red warning screen in browsers, and your brand reputation takes a serious hit. For website owners, developers, and domain investors, a blacklisted domain can be a silent killer of traffic and trust.
How to Check if Your Domain Is Blacklisted
Before you panic, you need to confirm whether your domain is actually blacklisted. There are several ways to do this, and using the right tools saves time.
1. Use a Blacklist Check Tool
The fastest method is to use a free online blacklist checker. Services like MXToolbox, MultiRBL, or WhatIsMyIPAddress let you enter a domain or IP and see results from dozens of blocklists in seconds. These tools check lists maintained by Spamhaus, Barracuda, SURBL, SORBS, and many others.
If you want to dig deeper into the health of your domain, our Domain Valuation tool includes reputation metrics that can hint at blacklisting issues. For a more technical audit, try the DNS Analyzer to see if your DNS records are misconfigured — a common trigger for blacklisting.
2. Check Your Email Deliverability
Send a test email to a service like Mail-Tester or Glocksoft. They'll score your email and flag any blacklist hits. If your score is low, you likely have a listing problem.
3. Monitor Browser Security Warnings
Google Safe Browsing and others will warn users if your site contains malware or deceptive content. You can check directly at https://transparencyreport.google.com/safe-browsing/search.
Common Reasons Domains Get Blacklisted
Knowing what caused the blocklist helps you fix it permanently. Here are the most frequent culprits:
- Spam complaints — recipients mark your emails as spam.
- Malware or phishing — your site was hacked and used to host malicious files.
- Poor email authentication — missing or incorrect SPF, DKIM, or DMARC records.
- Abused domain history — the domain was previously used for spam by a past owner.
- Shared IP reputation — if you're on a shared hosting IP, a neighbor's bad behavior can drag you down.
This last point is especially important: many blocklists focus on IP addresses rather than domain names. If your IP is dirty, even a clean domain will be affected. Use the Reverse IP Lookup to see what other domains share your server IP — you might find a toxic neighbor.
Step-by-Step: How to Fix a Blacklisted Domain
Once you've identified the problem, take these actions in order. Patience is key; delisting can take hours to weeks depending on the list.
Step 1: Clean Up the Root Cause
If your site was hacked, remove the malicious files, update all software (WordPress, plugins, themes), and change every password. For email issues, stop sending to old or purchased lists. Use a tool like Domain History to see if your domain was previously used for spam — if so, you may need to start fresh on a new domain.
Step 2: Fix Email Authentication
Set up SPF, DKIM, and DMARC records in your DNS. Many blocklists will blacklist domains that lack these even if you aren't spamming. The DNS Analyzer can help you verify that your records are correct and not missing.
Step 3: Request Delisting
Each blocklist has its own removal process. Visit the list's website, fill out the removal form, and explain the steps you've taken to fix the issue. Common ones include:
- Spamhaus —
https://www.spamhaus.org/lookup/ - Barracuda —
https://www.barracudacentral.org/lookups - SURBL —
https://surbl.org/removal
Always be honest. If you try to cheat the system, you'll likely end up permanently listed.
Step 4: Warm Up Your Sending Reputation
After delisting, gradually increase email volume from your domain. Start with small, highly engaged lists. Monitor your delivery rates using services like SendGrid or Amazon SES's reputation dashboard.
Step 5: Prevent Future Blacklisting
Set up monitoring. Many tools offer real-time blocklist alerts so you can react before a listing becomes a disaster. Also, regularly scan your website for malware and keep your software patched.
Real-World Example: A Hacked WordPress Site
Let's say you run an e-commerce store using WordPress. One day you notice your emails are bouncing and visitors see a "Deceptive Site Ahead" warning. You check with a blacklist checker and find your domain is on Google Safe Browsing and several email blocklists.
You investigate and discover a compromised plugin injected crypto-mining scripts into your site's footer. Here's the fix:
- Remove the plugin and update everything.
- Use a security scanner (e.g., Wordfence) to clean all infected files.
- Submit to Google Search Console for review.
- Request removal from each email blocklist.
- After approval, set up SPF/DKIM if you hadn't already.
Within a week, your domain is clean, and your traffic and deliverability return to normal.
Tools That Help You Stay Safe
Whose.Domains offers several utilities that can assist you in maintaining a clean reputation:
- DNS Analyzer — check your SPF, DKIM, and DMARC records.
- Reverse IP Lookup — see if your hosting IP has other nasty domains.
- Domain History — learn what a domain was used for before you buy it (a must for domain investors).
- SSL Checker — a missing or expired SSL certificate can also trigger warnings.
Final Thoughts
Domain blacklisting is stressful but not permanent. With the right checks and a systematic cleanup plan, you can restore your domain's reputation within days. The key is to act fast, fix the root cause, and learn proper email and website hygiene to avoid a repeat. Bookmark this guide and run a blacklist check at least once a month — it's a small habit that can save your online business.