Blacklist Checker
Check whether an IP or domain appears on email blacklists (DNSBLs), which can affect email deliverability. No signup. Ideal for diagnosing email delivery problems.
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This blacklist check looks up whether an IP or domain appears on email blacklists, known as DNSBLs, directly in your browser. Enter an IP or domain to check. No account, no install, so you can check your email deliverability reputation on any device in seconds.
How to Run a Blacklist Check Step by Step
- Enter the IP or domain. Enter the IP address or domain you want to check against email blacklists, such as your mail server's IP or your sending domain.
- Run the check. The tool looks up whether the IP or domain appears on email blacklists, the DNSBLs it checks.
- See the results. See whether the IP or domain is listed on any blacklists, indicating whether it appears on the DNSBLs checked.
- Note any listings. Note any blacklists the IP or domain is listed on, since being listed can affect email deliverability.
- Take appropriate action. If listed, you can look into why and address it, since a listing can hurt email delivery, following each blacklist's process to resolve it.
What Email Blacklists and DNSBLs Are
Email blacklists, known as DNSBLs (DNS-based blocklists), are lists of IP addresses or domains that have been flagged, often for sending spam or other issues. Mail servers use these lists to decide whether to accept or reject email, so if a sending IP or domain is on a blacklist, its email may be blocked or sent to spam. A blacklist check looks up whether an IP or domain appears on these lists.
Being on an email blacklist can seriously affect email deliverability. If your mail server's IP or your sending domain is listed, mail servers using that blacklist may reject your email or filter it as spam, so your messages do not reach recipients. So checking whether you are blacklisted is important for diagnosing and maintaining good email deliverability, since a listing can be the cause of email not being delivered.
The check tells you whether an IP or domain is listed or not listed on the blacklists it checks. Not listed is good, indicating the IP or domain is not on those blacklists. Listed indicates it appears on one or more, which can affect deliverability and is worth investigating and addressing. So the result shows your blacklist status, helping you understand a potential deliverability issue.
Blacklist checks are used by anyone concerned with email deliverability: people running mail servers, sending email, or diagnosing why email is not being delivered. Because a blacklist listing can cause email to be blocked or filtered, checking is a useful step in diagnosing deliverability problems and monitoring email reputation, so you can find and address a listing that may be hurting your email delivery.
Being Listed Versus Not Listed
| Result | Meaning | What to do |
|---|---|---|
| Not listed | Not on those blacklists | Good for deliverability |
| Listed | On one or more blacklists | Investigate and address |
| Affects | Email deliverability | Delivery can be blocked or filtered |
| Action | Follow removal process | Resolve the listing |
Who Uses a Blacklist Check
Pro Tips for Email Reputation
Common Blacklist Check Mistakes to Avoid
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Frequently Asked Questions
How do I run a blacklist check?
Enter the IP address or domain you want to check against email blacklists, such as your mail server's IP or your sending domain, and the tool looks up whether it appears on the email blacklists, the DNSBLs it checks. See whether the IP or domain is listed on any blacklists, note any listings, and take appropriate action, since being listed can affect email deliverability. If listed, you can look into why and address it, following each blacklist's removal process to resolve it. This lets you check your email deliverability reputation, seeing whether a blacklist listing might be causing email delivery problems, so you can find and address it to restore good delivery.
What are email blacklists and DNSBLs?
Email blacklists, known as DNSBLs (DNS-based blocklists), are lists of IP addresses or domains that have been flagged, often for sending spam or other issues. Mail servers use these lists to decide whether to accept or reject incoming email: if a sending IP or domain is on a blacklist, its email may be blocked or sent to spam by servers using that list. So DNSBLs are a mechanism mail servers use to filter unwanted email based on sender reputation. A blacklist check looks up whether an IP or domain appears on these lists, telling you your blacklist status. Being listed can affect your email deliverability, which is why checking is important for anyone concerned with whether their email reaches recipients.
How does being blacklisted affect my email?
Being on an email blacklist can seriously affect your email deliverability. If your mail server's IP or your sending domain is listed on a blacklist, mail servers that use that blacklist may reject your email or filter it as spam, so your messages do not reach recipients or land in their spam folders. So a blacklist listing can be the cause of email not being delivered or going to spam. This is why checking whether you are blacklisted is important: if you are experiencing delivery problems, a listing may be responsible. So being blacklisted undermines your email reaching people, making it crucial to check for and address any listing to restore proper email delivery, since the listing directly affects whether receiving mail servers accept your email.
What does it mean if I am listed or not listed?
If a blacklist check shows you are not listed, that is good: the IP or domain is not on the blacklists checked, which supports good email deliverability. If it shows you are listed, the IP or domain appears on one or more blacklists, which can affect your deliverability, causing email to be rejected or filtered as spam by mail servers using those lists. So being listed is worth investigating and addressing. A listed result indicates a potential cause of email delivery problems, prompting you to look into why you were listed and follow the removal process. So the check shows your blacklist status, with not listed being the desirable outcome and listed signalling an issue to resolve for better email deliverability.
What should I do if I am blacklisted?
If you are blacklisted, you should take it seriously and address it, since a listing can hurt your email deliverability. First, investigate why the IP or domain was listed, since understanding the reason, such as sending spam or a misconfiguration, helps you fix the underlying issue. Address that cause, so the problem does not recur. Then follow the specific removal process for each blacklist you are listed on, as different blacklists have their own procedures for requesting removal. Requesting removal without fixing the cause can lead to being relisted, so resolve the underlying issue first or alongside. So the steps are to investigate the cause, address it, and follow each blacklist's removal process, restoring your email reputation and deliverability by properly resolving the listing rather than ignoring it.
Who should check for blacklisting?
Anyone concerned with email deliverability should check for blacklisting: people running mail servers, who need to ensure their server's IP is not listed; people sending email, who want to confirm their sending IP or domain has a good reputation; people diagnosing why email is not being delivered, since a listing can be the cause; and people monitoring their email reputation, to catch listings early. So if you send email and care whether it reaches recipients, checking blacklists is useful. It is especially important when diagnosing delivery problems, as a blacklist listing is a common cause of email being blocked or filtered. So mail server operators, email senders, and anyone troubleshooting or monitoring email deliverability benefit from checking whether their IP or domain is blacklisted.
Does a clean check mean my email will always deliver?
A clean blacklist check, showing you are not listed, is good and supports deliverability, but it does not guarantee your email will always deliver, since email deliverability can have other causes beyond blacklists. Factors like your email configuration, authentication settings, content, and sending practices also affect whether email reaches recipients. So while not being blacklisted removes one potential problem, other issues could still affect delivery. So use the blacklist check as one part of ensuring good deliverability, alongside checking other email settings and following good sending practices. A clean check is reassuring for the blacklist aspect, but maintaining good email deliverability involves more than just blacklist status, so consider the other factors too if you experience delivery issues despite a clean blacklist result.
Is the blacklist check free?
Yes, it is completely free with no account and no usage limit. You can run as many blacklist checks as you like, as often as you like, at no cost. It runs in your browser on any device, so there is nothing to download or install, and you see whether an IP or domain is listed when you check. Use it to check your email deliverability reputation, diagnose delivery problems, and monitor whether your sending IP or domain is on email blacklists. Remember to check the actual IP or domain used for your email, address the cause if listed before seeking removal, and consider blacklist status as one part of overall email deliverability alongside other factors.