Check an IP address against blacklists
Enter an IP address to check it against eight public blacklists. Leave the field empty to check your own address. The check is free and requires no sign-up.
Result for 216.73.217.13
Which lists we check
Each list collects addresses by its own criteria, so being listed on one does not mean being listed on the others.
| List | What it collects | DNS zone |
|---|---|---|
| Spamhaus ZEN | Combined Spamhaus list: spam, infected machines and home connections. | zen.spamhaus.org |
| SpamCop | User-reported spam, entries expire after 24 hours. | bl.spamcop.net |
| Barracuda | Maintained by a mail filtering vendor, based on its own spam traps. | b.barracudacentral.org |
| UCEPROTECT L1 | Level 1 - individual addresses caught sending spam. | dnsbl-1.uceprotect.net |
| Blocklist.de | Addresses attacking SSH, FTP and mail servers within the last 48 hours. | bl.blocklist.de |
| InterServer | Mixed list: spam, port scanning, intrusion attempts. | rbl.interserver.net |
| DroneBL | Machines in botnets and open proxies. | dnsbl.dronebl.org |
| Tor Exit | Tor exit node - anonymous traffic, not abuse by itself. | tor.dan.me.uk |
How the check works
DNSBL blacklists are collections of IP addresses reported for spam, attacks or other abuse. They are not queried over the web but over DNS: to check 1.2.3.4 against zen.spamhaus.org, you ask for the 4.3.2.1.zen.spamhaus.org record. An answer means the address is listed, and its value says why.
Mail servers worldwide rely on these lists. If your address is listed, mail sent from it may land in spam folders or be rejected at connection time.
How to get delisted
Removing the entry is not enough on its own - if the cause remains, the address will be listed again within hours.
- Find the cause: an infected machine on the network, a misconfigured mail server acting as an open relay, or a website form being abused to send messages.
- Fix the problem and confirm that no suspicious traffic leaves the address any more.
- Go to the list operator site and fill in its removal form. Every list has its own - Spamhaus and SpamCop process them instantly, others after review.
Many lists drop entries automatically when no new reports arrive for a few days. On a home connection with a dynamic address, the entry may well concern whoever had the address before you.