How to Check If Your Domain Is Blacklisted

Your emails were getting through just fine last week. Now customers say they never arrived. Your website traffic dropped for no clear reason. A visitor mentions a browser security warning when they try to open your site.

These are classic signs of a blacklisted domain. Knowing how to check if your domain is blacklisted is the first step toward fixing it. This article covers everything from spotting the warning signs to getting removed and staying off blacklists for good.

Using Truehost for your domain and hosting? Log into your account to review your settings and keep your domain in good standing.

What Does It Mean When a Domain Is Blacklisted?

A blacklisted domain has been flagged by security organizations, email providers, or search engines as a source of spam, malware, or suspicious activity.

What is a Domain Blacklist?

A domain blacklist is a database that tracks domains linked to harmful activity. When your domain appears on one, other servers, browsers, or email clients use that information to block or filter your content.

How Blacklisting Affects Websites and Email

A blacklisted domain causes emails to land in spam or get blocked entirely. It can also trigger browser security warnings that stop visitors from reaching your site.

Signs Your Domain May Be Blacklisted

1) Emails Going to Spam

If contacts consistently find your messages in junk folders, your email deliverability may already be affected. This is usually the first symptom people notice.

2) Browser Security Warnings

When Chrome or Firefox displays a warning like “This site may harm your computer,” your domain has likely been flagged by a website blacklist like Google Safe Browsing.

3) Sudden Drop in Website Traffic

A sharp drop in organic traffic without any content changes can point to a blacklisting event or a search engine penalty.

4) Reports from Customers or Visitors

Sometimes the first sign comes from a customer saying they never received your email. Take these reports seriously and investigate right away.

How to Check If Your Domain Is Blacklisted

Using Online Blacklist Checkers

The fastest method is a free blacklist checker tool. MXToolbox checks your domain against dozens of blacklists at once and shows exactly which ones have flagged you.

Using Google Transparency Report

For browser-related issues, check the Google Transparency Report to see whether Google Safe Browsing has flagged your domain for malware or phishing. This is the same tool Chrome uses to generate security warnings.

Reviewing Server and Email Logs

If you have access to your hosting or email logs, look for unusual sending activity or unauthorized access. Logs can point directly to the problem source.

Common Domain Blacklists You Should Know

Spamhaus

Spamhaus is one of the most respected blacklist providers globally. A listing here can block your emails at major providers like Gmail and Outlook.

SURBL

SURBL flags domains found inside spam message bodies. If your domain appears in spam links, SURBL will catch it.

SpamCop

SpamCop builds its list from user-submitted spam reports. Even a small number of recipients marking your emails as spam can trigger a listing.

Barracuda Reputation Block List

Used by email security systems worldwide. Organizations using Barracuda products will block emails from any listed domain.

Google Safe Browsing

Flags websites distributing malware or running phishing pages. A listing here directly affects how browsers display your site to visitors.

Why Domains Get Blacklisted

1) Sending Spam Emails

Sending bulk emails to outdated or non-consenting lists generates spam complaints quickly. High complaint rates are one of the fastest routes to a blacklist.

2) Malware and Phishing Activity

If your website is hacked and used to host malware or fake login pages, security organizations will flag your domain automatically. This often happens without the owner knowing.

3) Poor Email Authentication

Missing SPF, DKIM, or DMARC records make it easy for spammers to send emails pretending to be from your domain. Blacklists see that abuse as coming from you.

4) Shared Hosting Issues

On shared hosting, your domain shares an IP address with other sites. If a neighboring site gets blacklisted for spam or malicious activity, your domain can sometimes be caught in the same listing.

How to Remove Your Domain from a Blacklist

1) Identify and Fix the Cause

Use your blacklist checker results to understand which lists you’re on and why. Fix the root issue first. Submitting a removal request before resolving the problem almost always results in getting listed again.

2) Secure Your Website and Email

Change all passwords, update your CMS and plugins, remove any malicious code, and configure SPF, DKIM, and DMARC correctly. This shows blacklist operators the problem has been resolved.

3) Request Delisting

Each blacklist has its own removal process. Spamhaus, SpamCop, and Barracuda all have online request forms. Be clear about what happened and the steps you’ve taken to fix it.

4) Monitor Afterwards

Check your domain reputation weekly for the first month after delisting. It’s common to get relisted if the underlying issue wasn’t fully resolved the first time.

How to Prevent Your Domain from Being Blacklisted

1) Enable SPF, DKIM, and DMARC

These email authentication records confirm to receiving servers that your emails are legitimate. Set them up through your DNS settings, most hosting providers make this straightforward.

2) Keep Your Website Updated

Outdated themes, plugins, and CMS versions are the most common entry points for attackers. Update everything regularly and remove anything you no longer use.

3) Scan for Malware Regularly

Schedule regular website security scans to catch infections early. Early detection means less time on a blacklist and less damage to your domain reputation.

4) Choose a Reliable Hosting Provider

A hosting provider that monitors for abuse and maintains clean server IP addresses reduces your risk significantly. Truehost offers secure hosting with the monitoring and support to help keep your domain off blacklists.

Common Mistakes to Avoid

• Ignoring security updates. Outdated software is the leading cause of website compromises.
• Sending bulk emails without permission. Unsolicited emails generate spam complaints that land you on blacklists fast.
• Skipping email authentication. SPF, DKIM, and DMARC are not optional if you care about email deliverability.
• Waiting too long to investigate. The longer a blacklisting issue sits unaddressed, the more damage it does to your domain reputation.
• Assuming it will resolve itself. Blacklists require active removal requests and won’t clear automatically.

FAQs

Ready to Protect Your Domain Reputation?

Knowing how to check if your domain is blacklisted is the first step, but staying off blacklists is an ongoing habit. Blacklisting can seriously damage your email deliverability, your search visibility, and the trust visitors have in your brand.

Most blacklisting issues are fixable when caught early. Regular monitoring, strong security habits, and a reliable hosting provider make all the difference.

Take action today: Register or manage your domain with Truehost and explore hosting built with security and reliability in mind. Find more tips on the Truehost blog.