Blacklist Checker
Is your mail server on a DNS blocklist?
Mail servers get blocked by reputation lists, and being on one is usually the reason your mail silently stops arriving. This checks an address against a set of public blocklists and — unlike many free checkers — tells a genuine listing apart from a list that simply refused the query, so you are never told you are blacklisted when you are not.
Frequently asked questions
I am listed. How do I get removed?
Fix the cause first — a compromised account, an open relay, or a mailing list nobody opted into. Then use the delisting form on that list's own site. Delisting without fixing the cause gets you relisted within days.
Why do some lists show as unavailable?
Several blocklists refuse queries that come from datacenter addresses or public resolvers, because their free tier is meant for mail servers checking their own traffic. A refusal is not a listing, and this tool reports it as neither.
Does one listing matter?
It depends which. A listing on a widely used list will bounce mail at many providers; an obscure list may affect almost nothing. Look at whether your mail is actually being rejected before panicking.