Blacklist monitor
Check whether your IP or domain is on a public email blacklist. We query 25+ DNSBLs (Spamhaus, Barracuda, SpamCop, SORBS, UCEPROTECT and more) live, and show every listing as it comes back.
We don't save the IP or domain you check.
How blacklist monitoring works
Every blacklist publishes a DNS zone where listed IPs return a record. We reverse your IP (or resolve your domain to its mail-server IP via MX), query each zone in parallel, and aggregate the answers. The full sweep usually takes under two seconds, and results stream in live as each list responds.
A clean result is reassuring but not a guarantee: receiving servers also use private blocklists, reputation scores, and content filters. If you send cold email, MailCull's verify-list workflow catches the typo, disposable, and dead-mailbox addresses that get you listed in the first place.
What is a DNS blacklist (DNSBL)?
A published DNS zone listing IP addresses with poor sending reputation. Receiving mail servers query these lists to accept, flag, or reject mail. A listing can route your messages to spam until it is cleared.
My IP or domain is listed. What do I do?
Read the listing reason, fix the cause (often a compromised account, a dirty list, or an open relay), then request delisting on the blacklist's own site. Most lists delist quickly once the underlying issue is resolved.
Does a clean result guarantee inbox placement?
No. Receivers also use private blocklists, reputation scores, and content filters. Authentication (SPF, DKIM, DMARC) and a clean recipient list matter just as much.
How often should I check?
Check before a new send, when deliverability drops, or after an incident. Listings can appear at any time, so re-check periodically if you send at volume.