Blocklist Lookup
Check a domain or IP address against real DNS blocklists used by mail servers and spam filters — spam, malware, phishing and general-abuse lists.
Enter a domain or IP address above to check it against real blocklists. No account needed.
The four kinds of list, and what a hit really costs you
Not every listing means the same thing — the category tells you what was actually observed.
Spam source lists
Track IPs and domains observed sending unsolicited email. The largest and most consulted category — Spamhaus ZEN, SpamCop and Barracuda are among the most widely trusted.
Domain and URI lists
Check the domain name itself, or links found inside message bodies, rather than the sending IP — used to catch phishing links and spam-advertised domains regardless of which server sent the message.
Policy lists
Flag technical policy issues rather than observed abuse — dynamic/residential IP ranges, open relays, or Tor exit nodes. A hit here doesn't mean abuse happened, only that the address matches a category some mail servers choose to restrict.
Reputation and abuse lists
Broader reputation databases covering botnet activity, compromised hosts and general abuse reports, used by both mail filters and network security tools.
Most people find out from a bounce, days late.
Blocklist Lookup shows a snapshot — the sources reachable right now. Domain Monitor is the account-based feature that tracks DNS, expiry and SSL changes on the domains you keep an eye on, so you catch a change before it becomes a delivery problem.
How blocklists work
Why you got listed: most listings follow observed behavior, not a manual decision — a compromised account sending spam, a shared IP whose neighbor was abusive, or a mail server with SPF/DKIM/DMARC misconfigured in a way that makes legitimate mail look suspicious.
Getting delisted: fix the underlying cause first — a listing source that reviews mid-cleanup usually relists shortly after. Each source runs its own removal process, linked from its row above; there is no single place to request removal from every list at once.
Staying off the lists: keep SPF, DKIM and DMARC correctly configured, monitor for compromised accounts, and avoid sending patterns (sudden volume spikes, high bounce rates) that make automated systems flag a domain even without any bad intent behind them.