BounceBlock.io
Free tool

Blacklist Checker

Enter a domain or sending IP and we'll check it against well-known DNS blacklists (DNSBLs) that mailbox providers use to filter mail.

How it works

  1. 1Enter a domain or IP address.
  2. 2We query several public blacklists via DNS.
  3. 3See whether it's listed anywhere that could hurt delivery.
Questions

Frequently asked

What is an email blacklist?

A DNSBL is a published list of domains or IPs known for spam. Mailbox providers check them when deciding whether to accept your mail.

I'm listed — what now?

Each blacklist has a delisting process. Fix the underlying cause first (a compromised account, a dirty list) or you'll be relisted.

Why might a check be inconclusive?

Some blacklists block queries from public DNS resolvers. We report those as unverifiable rather than guessing.

Can I check a whole list at once?

This free tool checks one at a time. To verify a full list — email, phone and company together — upload a CSV to BounceBlock and preview your first 100 rows free.

Stop wasting hours on dead leads.

Upload your list and see how clean it really is — free, in under two minutes.

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