About the Blacklist Checker
DNS blocklists publish IP addresses and domains that sent spam or were compromised. Mail servers query them in real time and may reject or filter your mail if you are listed. We query every list in parallel and verify each list is responding correctly before trusting its answer.
If you are listed, fix the cause first — an infected device, an open relay, a compromised account or a bad mailing list — then request removal using the link shown next to the listing.
What is an email blacklist?
DNS blocklists (DNSBLs) publish IPs and domains that sent spam or were compromised. Mail servers query them in real time. Being listed on a major list can block your mail entirely.