IP Blocklist Check
Check if an IPv4 address is listed on major DNS-based blocklists (DNSBLs) used by mail servers and firewalls.
About IP Blocklist Checking
DNS-based blocklists (DNSBLs) are used by mail servers, firewalls, and anti-spam systems to identify IP addresses associated with spam, malware, or other abuse. If your IP appears on a blocklist, your emails may be rejected or flagged.
- Spamhaus - The most widely used blocklist, covering spam sources, exploits, and policy violations
- SpamCop - Community-driven list based on user spam reports
- Barracuda - Maintained by Barracuda Networks for spam sources
- SORBS - Identifies open relays, proxies, and spam sources
- UCEPROTECT - Multi-level blocklist with individual IP and range-based listings
This tool checks your IP against 14 major blocklists using DNS queries. A "Listed" result means the blocklist has flagged the IP. Contact the blocklist operator to request removal if your IP is listed incorrectly.