Use the blacklist check tool to disclose the reputation of an IPv4.

IPv4:

Use this tool to check an IP address against the most common blacklist databases. If you believe your IP address or mail server has been wrongfully added to a blacklist or blocklist, this will help you determine if it has and what to do next.

What is a blacklist check?

An IP address blacklist check, or IP address blocklist check, is a procedure done to show if a URL or IP address entered is listed with a domain name server blacklist (DNSBL). There are dozens of DNSBLs online, all of which use different criteria for listing and delisting addresses. However, IP addresses or mail server IPs that exist on any of the lists are believed to be a source of spam, resulting in those addresses being blocked from sending emails.

Spam filters utilize various DNSBLs to verify that incoming emails do not come from blacklisted sites, which would be a red flag. These domain name server blacklists are generally the first line of defense against IPs or domains sending spam. However, in some cases, IP addresses that don’t send spam are added to the blacklist database. Users can use the free blacklist IP checker to find if their IP address was wrongfully blocked by the database.

How do I check if my IP is blacklisted?

Check for your IP address on blacklists by entering the address into the tool above. If you don't know your IP address, visit the WhatIsMyIP.com homepage to see your IP. The IP blacklist checker will search IP blacklists and report a table of various blacklists. It lists whether your server IP address has been blocked by each.

Domain name server blacklists don’t notify users when their IP address goes on a blacklist. Therefore, blacklist checks are essential for users, mail servers, or businesses who believe that they have a blacklisted IP address. Using the tool above is the easiest way to check your blacklist status.

How do I get my IP off a blacklist?

Even if your IP was added to an IP address blacklist, it’s possible to do an IP blacklist removal online. To fix a blacklisted IP address, first make sure that your network is free of malware, as databases sometimes blocklist IPs for infections users aren’t even aware of. If your network is clean, find the list that blacklisted your IP address and contact them directly for removal.

Each blocklist handles IP removal requests differently. You can't do a quick IP IP blacklist removal online, and unfortunately, databases can choose whether or not to honor requests; however, making a removal request still serves as the best method for clearing your IP address or mail server IP from the blocklist. If you’re an email system administrator and your server has been blacklisted, you will have to work with the various DNSBLs that listed you.

What causes IP blacklisting?

IP addresses can be blacklisted for many reasons. The intention is to protect other websites and users from dangerous IP addresses. However, sometimes blacklists wrongfully list other IPs on the list, resulting in a normal, safe IP being blacklisted. You may do a blacklist check online and find your own IP was blacklisted.

A blacklist typically adds an IP for the following reasons:

  • The IP appears to be the source of spam messaging
  • The IP is associated with a website containing inappropriate or dangerous content
  • Your device has a malware infection that could spread
  • You accessed the dark web or other illegal trading sources with the IP

Blacklisting websites for spam protection

As mentioned above, domain name server blacklists are the primary line of defense against spam as they block IP addresses believed to be spam accounts. However, there are also spam uniform resource identifier blocklists (SURBLs) that serve as backup defense. They are blacklists of websites noted for appearing in unsolicited emails; not all email spam filters are capable of using them. Spam filters that can utilize the SURBLs scan the body text of emails, extract any website addresses present, and check them against blacklists. If the server finds an address, it flags the message as spam and handles it accordingly.

Since both methods filter spam differently, they are most effective when combined. Unfortunately, as spammers become more clever, there is no method capable of catching every spam message. Users must be vigilant in checking their own inboxes and educating themselves on how to avoid email scams.

Reporting IP blacklisting by analyzing email headers

It's useful to learn how to analyze email headers using an email header analyzer tool; these tools inspect and return a sender's IP address. If you receive spam messages or experience harassment online via email, use the analyzer tool to inspect the email header and report the IP address to the anti-spam blacklists.