Email providers keep a blacklist of email addresses and IP addresses that are known for sending spam. From time to time, you may find yourself on a blacklist.
There are a number of ways this can happen, however the most common is when one website on your host has been hacked. This happened to me in the past. A hacker placed a malicious script on one of my websites that was using an old version of WordPress. They then used my host’s mail server to send thousands of spam emails. This placed my IP address on a number of known blacklists as a spammer.
Email providers are aware that this happens. That is why they allow you to remove your IP address if it has been placed on a list. They usually do not remove your IP from a blacklist unless you request it to be removed.
It is therefore up to you to monitor the status of your IP addresses frequently. You can do this through blacklist checking services. They will advise what blacklist services your IP has, or has not, been listed on.
In this page, I have listed many blacklist checking services that will verify whether your IP address has been placed on any blacklists.
Be sure to check out the blacklist monitoring article in my website hosting guide to read more about the benefits of monitoring IP addresses.
 | DNSBL.infoA free blacklist checking service that will check your IP on over 100 DNS based blacklists |
 | DNSBL LookupA simple blacklist checker that checks your IP in over 60 blacklist services. |
 | HetrixToolsHetrixTools offers uptime monitoring, blacklist monitoring, and a blacklist check. They check IPs against a list of 132 blacklists Their free service allows you to monitor up to 32 IP addresses with monitoring occurring every 24 hours and reports kept for 15 days. Signing up to their professional plan at $9.95 per month increases this limit to 512 IP addresses. |
 | IPVoidDeveloped by the NoVirusThanks Company, IPVoid will check an IP against multiple IP reputation engines and DNS based blacklists. |
 | MxToolboxMxToolbox is a fantastic service that will email you weekly reports on the status of your IP address. The free account allows you to track one IP address. Up to 10 IP addresses can be tracked for only $20 per month. |
 | RBLTrackerRBLTracker is a multi-channel blacklist monitoring for your website, email addresses, and social media accounts. They have a fair pricing system that operates on how many checks you perform. Pricing starts at $0.005 per check and goes down with the more checks you perform. They are one of the only blacklist monitoring services offering social media protection. Top social media companies such as Facebook and Twitter use the Facebook Threat Exchange network. RBLTracker protects your IP addresses to ensure your social media presence is not affected. |