🚫 Blacklist Checker

Check if an IP address is listed on spam, phishing, or malware blacklists that could affect email deliverability and website reputation.

Enter IP Address:

💡 Tip: Enter an IP address and click "Check Blacklist" to verify against major blacklist databases.

Enter an IP address and click "Check Blacklist" to view results.

What a blocklist lookup actually asks

The IP you type is sent to our server, which runs the queries live against DNS blocklists and returns what they say right now. A DNSBL lookup is an ordinary DNS question: the four octets are reversed and the list's zone is appended.

203.0.113.25  →  25.113.0.203.zen.spamhaus.org

  A record 127.0.0.x  = listed (the last octet says why)
  NXDOMAIN            = not listed

So "not listed" is only ever a statement about the lists that were asked, at the moment they were asked. Mailbox providers keep private reputation data as well, and a clean DNSBL result does not mean your mail is reaching inboxes.

Which address to check

The sending IP, not your domain. For email that is the public address of the machine that hands the message over - read it from the topmost Received: header of a message you sent.
If you send through Google Workspace, SES or Mailgun you are checking their shared IP. Its reputation is theirs to manage, and only they can file a delisting.
Home and office broadband ranges sit on policy lists by design. That entry says "dynamic space, do not accept direct mail from here" - it is not a mark against you.

Cloud IPs change hands. A fresh instance can arrive already listed because of the previous tenant, so check before you send on it.

Frequently asked questions

Why is my IP blacklisted when I don't send spam?

The usual causes are a compromised mailbox sending through your server, an open relay, a stale mailing list generating spam-trap hits, or an address you inherited from a previous user of that IP.

Can I check a domain name instead of an IP?

The lookups are per address, so resolve the host first - dig +short mail.example.com - and check the address it returns.

How long does removal from a blacklist take?

Automatic listings expire on their own, typically in a few days once the sending stops. Manual delisting through the list operator's form is usually same-day, but you are re-listed if the underlying cause is still there.