What is an IP blacklist?

An IP address blacklist is also known as a Real time Blacklist(RBL) or DNS Blacklist (DNSBL). It is a list that prevents mail servers from sending email as a spam blocking measure. If your mail server has been blacklisted, some (or all) emails you send may never be delivered. There are currently more than 100 IP blacklists services and each has different criteria for adding domains or IPs to their list.

Why is my IP on a blacklist?

IP addresses are blacklisted for various reasons. The IP may be listed on one blacklist, or on multiple different blacklists. IP blacklists are maintained independently and each has different criteria for listing and delisting an IP address on the list.

IPs could be blacklisted due to malware, viruses, or spam. If a computer has a virus or malware and it constantly pings or tries to connect to other computers, it is bound to at some stage communicate with a computer where it is seen as an 'attack'. The admin then blocks the IP address and reports it accordingly. If spam is sent from the IP, or a mail server is used that is not configured properly and is used by third parties to send spam, the IP address will be blacklisted.

If a DHCP IP address is used and you do not spam and don't have malware or viruses, it is possible that a person who used the IP address previously was sending spam or had a virus. You may have done nothing wrong.

How can I see if my IP is blacklisted?

There are a number of blacklist checking sites where you can check if your IP Address is on a blacklist.

If you sending emails is affected by the blacklisting of the sending IP address, you may receive a bounce notification. The message will indicate that your email was rejected because the IP is listed on a blacklist.

How do I get my IP address off a blacklist?

• Step 1 - The first step is to ensure that no device on the network is infected with a virus or malware. Use an anti-virus solution like Bitdefender, Avast, Norton, Panda.
• Step 2 - Once you are sure the network is virus free and it does not send any unauthorized traffic, find the list where the IP address is blacklisted. You may use our IP blacklist checker or a similar one.
• Step 3 - Then, contact them to ask for removal. Blacklists will have different methods to follow to request removal of an IP. If you make a removal request, it does not necessarily mean that the request will be honored.

Blacklists will have different methods to follow to request removal of an IP. If you make a removal request, it does not necessarily mean that the request will be honored.

Summary

For average home users, having their IP address blacklisted will probably not have any impact on their normal surfing. Business running their own mail servers may, however, have problems getting unlisted. They need to ensure all devices on the network is clean and configure the mail server correctly and lock it down so it can’t send unauthorized messages.