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Blacklist checkfor an IP or domain
Is a sending address on a public blocklist? We query the Passive Spam Block List live and say plainly which lists we do not check, and why.
Which lists we check, and which we do not
Most blocklist checkers query a dozen lists at once. Most of those lists publish terms that limit who may query them for free, and a free tool on a company's website is a commercial setting. We read the terms and kept to what they allow.
| List | Checked here | Why |
|---|---|---|
| PSBL | Yes | Anybody is free to use PSBL. |
| Spamhaus (ZEN, DBL) | No | Spamhaus offers its free public DNS lists for non-commercial use, and refuses queries that arrive through public resolvers. Look an address up on Spamhaus's own checker. |
| SURBL | No | SURBL's free query service is for individuals and organizations with fewer than 1,000 users or 250,000 messages a day, and does not cover products or services that charge a fee. |
| Barracuda, SpamCop, UCEPROTECT, URIBL | No | We could not confirm that their terms let a free tool on a commercial site query them. Barracuda and SpamCop have their own lookup pages: Barracuda, SpamCop. |
Terms read on 6 November 2026; they change, and the source for each is in our records.
How the check works
- Enter an IPv4 address, or a domain. IPv6 is not supported: PSBL lists IPv4 only.
- For a domain we look up its A record and any single
ip4:address in its SPF record, up to 6 addresses. - Each address is asked of PSBL by DNS. No answer means not listed; an answer means listed; anything else is shown as "No answer", never as listed.
- Private, loopback and reserved addresses are never queried.
If an address is listed
- Stop sending from it
More mail from a listed address adds to the problem.
Fix: Pause the campaign or mailbox until you know why. - Find the cause
A compromised mailbox, a purchased list or a tool sending without opt-in are the usual reasons.
Fix: Review what was sent and to whom, and fix the source. - Ask for removal
PSBL says removal of an address is instantaneous, though it can take time to reach nameservers.
Fix: Use the removal tool on the list's own site, after the cause is fixed.
Questions
Why only one list?
A blocklist is somebody's service, and each sets its own terms. Anybody is free to use PSBL. The others either limit free use to non-commercial users or we could not confirm a free tool on a commercial site may query them. We would rather check one list properly than query the rest against their terms.
Does "not listed" mean my domain is clean?
No. It means PSBL has no listing for the addresses we checked. You can be on a list we do not query. For the others, use each list's own lookup, linked above.
Why is a domain checked through IP addresses?
PSBL lists IPv4 addresses, not domains. For a domain we check the addresses it publishes: its A record and any single
ip4: address in its SPF record. Mail sent through a big provider comes from the provider's addresses, which belong to the provider, so there is often nothing of yours to check.I am listed. What do I do?
Stop sending from that address, find out why it sent what got it listed (a compromised account, a bad list), fix that, then request removal. PSBL says removal of an address is instantaneous, though it can take time to reach nameservers.
Do you keep the addresses I check?
No. The check is DNS lookups answered on the spot. Only a rate-limit counter for your network is kept, and private or reserved addresses are refused.
Outlevo watches this for you
Every sending domain is checked daily against Spamhaus and SURBL, and a campaign pauses itself above 3% hard bounces or 5% unsubscribes over its last 200 sends, or at a spam complaint.