Free deliverability tool

Blacklist Checker

Check whether an IP address or domain is listed on the major real-time DNS blacklists used by mailbox providers.

If you enter a domain, we resolve the first A record and scan that IP.

What is a DNS blacklist?

A DNSBL (DNS-based Blackhole List) is a real-time list of IP addresses associated with spam, malware, or open proxies. Mailbox providers query these lists when filtering inbound mail — being listed on even one major list can tank your deliverability.

What we check

We query 10 of the most widely used DNSBLs including Spamhaus ZEN, SpamCop, Barracuda, SORBS, CBL/abuseat, PSBL, UCEPROTECT and NiX Spam.

If you are listed

  • Stop sending immediately — review recent campaigns, bounce rates and spam complaints.
  • Visit the provider's removal page (linked in the reason column where available).
  • Warm a new IP gradually if removal isn't possible.

Avoid it next time

Use dedicated IPs, verify lists before sending, throttle volume per inbox, and monitor blacklists daily. Every Icemail sending IP is monitored continuously.

Ship cold email that actually lands

Icemail bundles dedicated infrastructure, warmup, enrichment, and a unified inbox so your deliverability stays green.

See pricing