🚫 Blacklist Checker

What a blacklist check actually asks

A blacklist (DNSBL) is a list of IP addresses or domains linked to spam, published as a DNS zone. Checking one is a DNS question: reverse the IP, attach the list's zone name, ask. No answer means not listed; an answer is a code in the 127.0.0.x range, each list using its own codes. This tool checks an IP against Spamhaus ZEN, SpamCop and Barracuda, and a domain against Spamhaus DBL and URIBL. Before trusting any list, it runs a control query for a test entry the list deliberately keeps listed.

Why some results say "could not check"

• Public resolvers get blocked. Lists like Spamhaus and URIBL restrict the big free resolvers (Google, Cloudflare) that a browser tool must use, answering with a blocked or refused code. When that happens this tool says so instead of guessing. A later version will run checks through our own resolver, which lists treat as a normal query.
• Codes are list-specific. 127.0.0.1 from URIBL means "query refused", not "listed", and Spamhaus uses different ranges for listings, domains and its blocked message. Reading every 127 answer as listed is how naive checkers flag almost everything.
• One list is not every list. Mail receivers combine many lists with content and reputation signals, so treat a clean result here as a strong indicator, not a verdict.

Frequently asked questions

I am listed. How do I get off the list?

Fix the cause first: a hacked account, a website sending spam, a bought mailing list. Then use that list's own removal page. Most listings expire on their own once the behaviour stops. Never pay anyone promising instant delisting; only the list operator can remove you.

What is 127.0.0.2 and why is it listed?

It is a test address, kept by long-standing convention so anyone can verify a blacklist is responding. IP lists keep it permanently listed on purpose. It is not a real spammer. This tool uses it as a control: a list that cannot confirm its own test entry is not trusted on anything else.

My IP is clean but the previous owner of it spammed. What now?

Listings attach to the address, not the person, so shared and reassigned addresses inherit history. If it is stale, use the removal page; if the address keeps collecting neighbours' listings, ask your provider for a different address or a dedicated mail IP.

Does a clean result mean my email will reach the inbox?

No. It removes one common cause of rejection. Delivery also depends on SPF, DKIM and DMARC, on content, and on recipient history. If you are troubleshooting mail, run the SPF, DKIM & DMARC Checker here next.