Blacklist (RBL) Checker
Check a domain and its mail-server IPs against well-known DNS blocklists that affect email deliverability.
Result for kling4ai.app
Not listedIP blacklists
| IP | Blocklist | Status | Reason |
|---|---|---|---|
| 104.21.28.218 | Spamhaus ZEN | Clean | |
| 104.21.28.218 | Barracuda | The resolution lifetime expired after 3.104 seconds: Server Do53:8.8.8.8@53 answered The DNS operation timed out. | |
| 104.21.28.218 | SpamCop | Clean | |
| 104.21.28.218 | SORBS | Clean | |
| 104.21.28.218 | PSBL | Clean | |
| 104.21.28.218 | s5h.net | Clean | |
| 172.67.147.182 | Spamhaus ZEN | Clean | |
| 172.67.147.182 | Barracuda | The resolution lifetime expired after 3.104 seconds: Server Do53:8.8.8.8@53 answered The DNS operation timed out. | |
| 172.67.147.182 | SpamCop | Clean | |
| 172.67.147.182 | SORBS | Clean | |
| 172.67.147.182 | PSBL | Clean | |
| 172.67.147.182 | s5h.net | Clean |
Domain blocklists
Spamhaus DBL
Clean
SURBL
Clean
FAQ
What is a DNSBL/RBL?
A DNS-based blocklist of IPs or domains associated with spam. Mail servers query them to filter incoming mail.
I'm listed - what now?
Fix the underlying issue (open relay, compromised account) then request delisting on the provider's site.
Does a listing block all my mail?
It depends on which receivers use that list, but Spamhaus listings in particular hurt deliverability widely.
About blacklist checks
We resolve the domain's IPv4 addresses and look each one up in several DNS blocklists, plus the domain itself in domain-based blocklists. These are standard DNS queries - no accounts or API keys.
Pair this with your email authentication (SPF/DMARC/DKIM) to maximize inbox placement.