GUIDE
Email blacklists (DNSBLs) explained — and how to get delisted
What DNS blacklists are, which ones matter, and what to do when you are listed.
A DNS blacklist (DNSBL/RBL) is a zone that answers “listed” for IP addresses or domains that sent spam, are compromised, or should not send mail directly (dynamic IP space). Mail servers query several lists before accepting a message.
Which lists matter
Spamhaus ZEN (SBL, XBL, PBL) and Spamhaus DBL have the widest adoption, followed by SpamCop, Barracuda, SURBL and URIBL. Listings on smaller lists rarely affect delivery but hint at a problem.
Getting delisted
- Find the cause: compromised account, open relay, malware, misconfigured forwarding.
- Fix it — most operators re-list within hours otherwise.
- Use the operator’s removal form (linked in every StatusDNS result).
Run a Blacklist Check now or monitor your IPs to be alerted the moment you are listed.