Is your sending IP on a blocklist?
Enter an IPv4 address, or a domain to check the addresses of its mail servers. We query public blocklists whose terms allow free use, live, and tell you exactly which ones.
Check an IP or domain
Lists we check
Only lists whose published terms let a commercial website query them for free.
PSBL (Passive Spam Block List)
IP addresses that sent mail to spam traps.
Terms: “Anybody is free to use PSBL.” Source, read 8 November 2026.
DroneBL
Open proxies, infected machines and other abused hosts (not spam reports).
Terms: Free for commercial and non-commercial use. Source, read 8 November 2026.
Lists we don’t check, and why
- Spamhaus (ZEN, DBL)Free public mirrors are for non-commercial use; commercial tools need a paid data feed. Their terms, read 8 November 2026.
- SURBLAny product or service using its data needs a usage agreement. Their terms, read 8 November 2026.
- URIBLPublic zones are for low-volume end users; commercial use is through a paid data feed. Their terms, read 8 November 2026.
- SpamRATSFree only for non-commercial use, with a registered key. Their terms, read 8 November 2026.
Inside Inboxed, every sending domain is checked against domain blocklists every 6 hours, and a listed domain pauses its mailboxes. Also try the SPF, DKIM and DMARC checker.
Part of Deliverability suite in Inboxed. Placement tests with Gmail tabs, DMARC reports, Postmaster spam rate, blocklist and DNS checks.
See Deliverability suiteStart freeQuestions
Which IP should I check?
The address of the server that sends your email. Open an email you sent, view the original message, and look at the first Received header from your provider. If you send through Google Workspace or Microsoft 365, those servers are shared by millions of senders and your reputation lives mostly in your domain.
Why don’t you check Spamhaus?
Spamhaus’s free public mirrors are for non-commercial use; a commercial tool needs a paid data feed. The same goes for SURBL and URIBL. We only query lists whose published terms allow us to, and tell you which those are.
What does “couldn’t check” mean?
Before every check we look up each list’s test entry. If it doesn’t come back listed, the list isn’t answering us right now, so we never show a “not listed” we can’t trust.
I’m listed. What now?
Find the cause first: a compromised account, a form bots abuse, or a bought list. Fix it, then request removal on the list’s site. Delisting without fixing the cause usually means being listed again.
Is there a limit?
10 checks per network every 10 minutes, and a cap for the whole site, so the volunteer-run lists we query never see more than light traffic from us.
Warm up today. Launch when you’re ready. Pay only for emails that send.
No subscription, no card to start. Connect a mailbox and warmup begins in under a minute.