IP Blacklist Checker

How to use this blacklist checker

  1. Enter an IPv4 address.
  2. It's checked against several major email blacklists (DNSBLs) at once.
  3. A listing means mail servers may reject or flag email from that IP as spam.

How does a DNSBL check work?

Each blacklist publishes its list as a special DNS zone — checking an IP means querying a reversed version of it against that zone. A response means the IP is listed; no response means it's clean, at least for that particular list.

My IP is listed — what do I do?

Each blacklist has its own delisting process, usually a form on their website — search for the specific list's name plus "delisting" or "removal request" to find it.

Does this check every blacklist that exists?

No — there are dozens of DNSBLs in existence. This checks several of the most widely used ones, which cover the majority of real-world impact, but a clean result here doesn't guarantee a clean result everywhere.