---
title: "Blacklist Checker | Refresh List"
description: "Check selected DNS blocklist signals for a domain or public IPv4 address."
url: https://refreshlist.net/tools/blacklist-checker
last_updated: 2026-09-25
---

[Refresh List](/) › Tools

# Blacklist Checker

Use this working tool to inspect structure, plan credits, or query a domain without confusing that action with mailbox verification.

PUBLIC DNSBL SIGNAL CHECK Sending domain or IPv4 address 

We resolve a domain to its public IPv4 address, then query selected DNS blocklist signals. No email is sent and no mailbox is contacted. 

COMMON QUESTIONS 

## Blacklist signals, answered.

What does the blacklist score measure?+

It summarizes the selected DNS blocklist signals checked for the resolved public IPv4 address. It is not a universal sender-reputation score.

What does Clear mean?+

No listing signal was returned by that specific blocklist at the time of the lookup.

What does Listed mean?+

That blocklist returned a listing signal for the checked IP. Confirm the result with the list operator before taking action.

What does Unknown mean?+

The lookup was unavailable or inconclusive. Unknown is not the same as Clear.

Which blocklists are checked?+

The tool checks Spamhaus ZEN, SpamCop Blocking List, and Barracuda Reputation Block List signals. Coverage is intentionally limited and transparent.

Can a clean result guarantee inbox placement?+

No. Inbox placement also depends on authentication, reputation, complaints, bounces, content, engagement, and recipient policy.

Why does a domain resolve to more than one IP?+

Domains can use multiple mail servers. The checker evaluates up to three returned public IPv4 addresses so results remain quick to understand.

Can this tool check IPv6?+

The current public checker evaluates IPv4 addresses. IPv6 blocklist coverage can be added as a separate enhancement.

How often should I run a blacklist check?+

Run it after a sudden bounce or complaint increase, a sending-domain change, or a blocklist notification. Avoid treating a single snapshot as a permanent status.

What should I do if my IP is Listed?+

Confirm the listing, review recent bounces and complaints, fix authentication, pause risky sending, and follow the blocklist operators removal guidance.

Does Refresh List contact the mail server?+

No. It uses DNS lookups only and does not send email or open an SMTP session.

## Sitemap

- [All Public Pages](https://refreshlist.net/sitemap.md)
- [Email Glossary](https://refreshlist.net/glossary)
- [Read This Page And Use Interactive Features](https://refreshlist.net/tools/blacklist-checker)