Email Blacklist Check (DNSBL / RBL)
Check whether a mail server IP or a domain is listed on spam blacklists such as Spamhaus, SpamCop, Barracuda and UCEPROTECT — the usual reason mail suddenly bounces or lands in spam.
How it works
How DNS blacklists work
What a listing means
Blacklists collect IPs and domains that sent spam, hit spam traps or look like compromised hosts. Receiving mail servers query them for every incoming connection.
IP and domain lists
IP lists check the server that delivers your mail. Domain lists check the domains that appear in the message, such as links and the sender address.
Getting delisted
Fix the cause first — a hacked account, an open relay or a bad mailing list — then use the list's removal page. Many lists also expire entries on their own.
FAQ
Frequently asked questions
Why is a list shown as unavailable?
Some lists, such as Spamhaus, refuse queries that arrive through large public resolvers. When we cannot get a usable answer we say so instead of guessing.
I use Gmail or Microsoft 365. Should I check their IPs?
Their shared IPs are managed by the provider. Check your own domain instead, and check SPF, DKIM and DMARC with the email checker.
Does a single listing matter?
It depends on the list. Spamhaus, SpamCop and Barracuda are widely used; listings on small lists rarely affect delivery.
More free tools
All toolsBusiness email on your domain