Blacklist Check
Check an IP address or domain against major email DNS blacklists (DNSBLs).
About the Blacklist Check
Blacklist check tells you whether an IP address or domain appears on the major email DNS blacklists (DNSBLs). Enter a mail server IP or a domain and the tool queries a spread of well known lists, then reports which ones list it, which are clean, and which could not be reached.
DNSBLs are databases of addresses known for sending spam. Receiving mail servers check them before accepting a message, so a listing can quietly send your email to spam or get it rejected outright. If you run a mail server or send marketing or transactional email, checking the sending IP is the first step when deliverability drops. If you enter a domain, the tool resolves it to an IP and checks that.
A listing is not always your fault: shared hosting, a previous owner of the IP, or a brief misconfiguration can all cause one. Each blacklist has its own delisting process, usually linked from the detail it returns. Fix the underlying cause first, then request removal, or many lists drop you automatically once the bad behavior stops.
The check runs on our server, which queries the public blacklists on your behalf, because a browser cannot make these DNS queries. Note that some lists, including Spamhaus, refuse queries from cloud servers and will show as Unknown here; confirm those on the provider’s own page. The IP or domain you enter is sent to our server for the check and is not stored.
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Frequently asked questions
What is a DNSBL or email blacklist?
A DNS based blacklist is a published list of IP addresses associated with spam. Mail servers query these lists in real time and may refuse or downgrade mail from listed addresses.
Should I check my IP or my domain?
Check the IP address your mail actually sends from, since DNSBLs list IPs. If you enter a domain, the tool resolves it to an IPv4 address and checks that, which may not be your real sending IP if you use a separate mail provider.
Why are some lists shown as Unknown?
Several blacklists, notably Spamhaus, block lookups that come from cloud and datacenter IP ranges. Our server runs in the cloud, so those queries are refused and reported as Unknown rather than guessed. Verify them on the provider’s own lookup page.
I am listed. How do I get removed?
First fix the cause: secure any open relay or compromised account, set up SPF, DKIM, and DMARC, and stop the spam. Then use the delisting form linked from each blacklist. Many lists also expire entries automatically once the abuse stops.
Is the address I enter stored?
No. The IP or domain is sent to our server only to run the blacklist queries and is not logged or stored.