Tool
IP Blacklist Check
Check whether an IPv4 address is listed on major DNS blocklists (DNSBLs). Useful before sending email or when mail is bouncing. Checking your own IP? See it on the home page →
What an IP Blacklist Check Does
Mail servers fight spam by consulting DNSBLs, published lists of IP addresses with a bad sending reputation. If your IP is on one, your email may be delayed, filtered to spam, or rejected outright. This tool queries eight established blocklists at once and reports where, if anywhere, the address appears.
- Listed: the blocklist currently includes this IP.
- Not listed: the blocklist has no record of it.
- Couldn't check: that list did not return a clear answer (often a resolver limit).
The address checked is your public IP reputation. Not sure what your public IP is, or want to inspect another? Use the What Is My IP tool or the IP address lookup.
What to Do If You're Listed
- Find the cause: a compromised device, open relay, or misconfigured mail server.
- Fix it: clean up the source so the IP stops the behaviour that got it listed.
- Request delisting: use each blocklist's own removal form; they are independent.
- Wait and recheck: some lists auto-expire clean IPs; re-run this check to confirm.
Frequently Asked Questions
What is an IP blacklist (DNSBL)?
A DNSBL (DNS-based blocklist) is a published list of IP addresses known for sending spam or malicious traffic. Mail servers query these lists in real time and may reject or flag email from a listed IP. Spamhaus, SpamCop and Barracuda are well-known examples.
Which blocklists does this tool check?
It queries eight established DNSBLs in real time: Spamhaus ZEN, SpamCop, Barracuda, DroneBL, PSBL, Mailspike, UCEPROTECT-1 and s5h.net. Mail providers weight these differently. Spamhaus carries the most influence, while stricter lists such as UCEPROTECT are used less widely, so a listing there on its own rarely blocks your mail.
Why is my IP address blacklisted?
Common reasons include sending spam (sometimes from a malware-infected device or a compromised account), a misconfigured mail server, an open relay, or inheriting an IP whose previous owner was listed. Addresses in dynamic/residential ranges are also frequently listed by policy.
How do I get my IP removed from a blacklist?
Fix the underlying cause first (stop the spam source, secure the server, close any open relay), then use the delisting form on each blocklist that lists you. Every DNSBL runs its own. Some remove entries automatically after the IP stays clean for a while.
Does being on a blacklist affect my website?
DNSBLs mainly affect email deliverability: listed IPs have trouble sending mail. They do not usually block normal website browsing, but a poor IP reputation can still affect some security filters and forms.
Why is my IP listed when I never sent spam?
On a shared or dynamic IP, someone else's past behaviour (or a blanket policy against residential ranges) can get the address listed. This is one reason mail is best sent from a dedicated IP with a clean history.
Do you store the IP addresses I check?
No. Each check runs live DNS queries against the blocklists and returns the result to you; we do not log or store the addresses you look up.