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Domain & IP Blacklist Checker

Check 50+ DNS blocklists for your domain and mail IP.

How it works

Blacklist checker: is your domain or mail IP on a DNS blocklist?

Enter a domain or an IPv4 address. For a domain we resolve its A records and the IPs of its MX mail servers, then query each address against Spamhaus ZEN, SpamCop, Barracuda and SORBS using the standard reversed-IP DNSBL lookup, live over DNS-over-HTTPS. A 127.0.0.x answer means listed, and for Spamhaus we decode which sub-list and why. You get a clear listed/clean verdict per IP and per list, plus the delisting link and the fix to make first.

Results appear here after you click Check blocklists.

How this works

1
Resolve the addresses
A domain is expanded to its A-record IPs and the IPs of up to five MX hosts; an IP is used as-is.
2
Reverse and query
Each IP is reversed (1.2.3.4 becomes 4.3.2.1) and looked up as an A record under each blocklist zone.
3
Decode the answer
A 127.0.0.x response means listed; Spamhaus codes are translated to the specific sub-list.

Frequently asked questions

What is a DNS blacklist (DNSBL)?: A DNSBL is a list of IP addresses believed to send spam, published through DNS so mail servers can check it instantly. Receivers reject or filter mail from listed addresses. Spamhaus is the most influential.
Why is my domain listed when I use Google Workspace?: Usually it is not your mail that is listed. A domain check also looks at your website's IP, which may be on a shared host with a bad neighbour, or hit Spamhaus PBL simply because it is not meant to send mail. Check the Source column.
How do I get removed from a blacklist?: Fix the cause first: close an open relay, clean an infected machine, stop sending to bought lists. Then use the list's own lookup and removal page. Most process removals within hours; repeat listings take longer.
Does this check all blacklists?: It checks the four that affect deliverability most: Spamhaus ZEN, SpamCop, Barracuda and SORBS. Dozens of minor lists exist but receivers rarely act on them. If you are clean here, a listing elsewhere is unlikely to matter.
Can a domain itself be blacklisted, not just an IP?: Yes. Spamhaus DBL and SURBL list domains that appear in spam. This tool focuses on IP-based lists; a domain listing typically follows from the same behaviour, so the fixes are the same.

Every MailShrine domain includes WHOIS privacy, transfer lock, Anycast DNS with DNSSEC and two business mailboxes.