IP Blacklist Check.
Find out if an IPv4 address or mail server is on a spam blacklist. The tool asks eight well-known lists and shows which, if any, list the address.
100% free, no sign-up. To stop automated scanning, each browser can run up to 10 scans per tool every 3 hours; only that count is kept (privacy).
What Is an IP Blacklist Check?
An IP blacklist, also called a DNSBL, is a list of IP addresses that have been seen sending spam or showing other abuse. Mail servers check it over DNS before accepting a message: if the sending IP is listed, the mail is rejected or put in the spam folder.
An address can be listed because a website or mailbox on the server was hacked, because a script sent spam, because of poor sending practice, or because a previous owner of the address behaved badly. New VPS addresses are sometimes listed when you receive them.
This check asks eight widely used lists for one IPv4 address. A "not listed" result is good news, but not a guarantee: other lists exist, and a list that times out looks the same as a clean answer.
Is Your Address on a Blacklist?
Mail servers look up the sender's IP on these lists before accepting email. A listing is a common reason for rejected or missing mail.
Eight major lists
Spamhaus ZEN, SpamCop, Barracuda, Passive Spam Block List, UCEPROTECT level 1, DroneBL, s5h.net and Mailspike.
Clear result per list
Each list shows "Not listed", "LISTED" with its return code, or a note that it could not be checked.
Reverse DNS shown
The PTR hostname of the address, since a missing or wrong one adds to spam suspicion.
What to do next
If an address is listed, the result explains how to find the cause and how to ask for removal.
Common Problems and Fixes.
If an address is listed, work through these.
I am listed on Spamhaus
Open the Spamhaus lookup for your IP, read the reason, fix the cause (for example a hacked site or open relay), then request removal on their site. It is free.
I am listed only on UCEPROTECT level 1
Level 1 lists single addresses that sent spam to its traps. Fix the cause; it expires by itself after a week. Ignore sites that ask for payment to remove you.
I am listed on SpamCop
SpamCop listings expire by themselves, usually within a day or two once the spam stops. Fix the cause so it does not return.
I just got a new server and the IP is listed
The previous user may have misused it. Ask your provider for another address, or request removal and tell the list the address is newly yours.
I am not listed but mail is rejected
Check reverse DNS with the reverse DNS lookup and SPF, DKIM and DMARC with the email authentication checker. Read the bounce message: it names the reason.
A list says it cannot be checked
Some lists refuse lookups from busy public resolvers. Try again later, or use that list's own website for a direct lookup.
Related Free Tools.
Frequently Asked Questions
Quick answers about this tool.
A Clean Address for Your Mail Server
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