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Blacklist Problem Knowledge Base

What is an IP or domain blacklist problem?

A blacklist, also known as DNSBL or RBL (DNS Blacklist or Realtime Blacklist respectively) is a spam blocking list, that can prevent your mail server from sending email. If you find your mail server has been blacklisted, some email you send may never be delivered. Currently, there are more than 100 organizations that run these lists and each one has different specifications for adding your domain or ip to their list.

How does MxToolbox help?

We provide a free online blacklist check tool, where you can check if your domain or IP address is blacklisted. You can also learn how to get off and stay off blacklists with monitoring and setup a free blacklist monitor.

Not sure where to begin? We recommend starting with a Blacklist Check

Benefits to Blacklist Monitoring:

  • 30 blacklists are checked automatically for free customers
  • Get alerted instantly if you land on a blacklist, as well as when you are removed
  • Upgrade: Over 100 blacklists checked multiple times every day and free blacklist removal support