IP Abuse & Blacklist Checker - Free RBL
Check any IP address against major DNSBL blacklists, calculate abuse reputation score, identify botnet proxies, and generate ISP abuse reports.
Major DNSBL / RBL Blocklist Audit
| Blacklist Provider | Zone | Status | Listing Reason / Classification |
|---|---|---|---|
| Spamhaus XBL | xbl.spamhaus.org |
Known Tor exit node / anonymizing proxy | |
| Barracuda BRBL | b.barracudacentral.org |
Automated scraping and vulnerability scan origin | |
| SpamCop SCBL | bl.spamcop.net |
CLEAN | No active high-volume email spam reports |
| SORBS SPAM | spam.dnsbl.sorbs.net |
Dynamic proxy exit subnet | |
| AbuseIPDB Index | api.abuseipdb.com |
247 individual community abuse reports | |
| UCEPROTECT Level 1 | dnsbl-1.uceprotect.net |
CLEAN | Single IP not flagged in direct spam traps |
Standard RFC 5965 Abuse Report Template
IP Reputation & Delisting Best Practices
Differentiate SBL vs PBL
Spamhaus SBL marks actively verified spam emitters, whereas PBL (Policy Block List) merely identifies consumer broadband IPs that shouldn't host direct mail servers.
Fix Root Causes Before Delist
Submitting delist requests while malware, misconfigured postfix relays, or unpatched WordPress plugins remain active results in immediate relisting and permanent blacklist penalties.
Maintain Reverse DNS (PTR)
Major mail receivers (Gmail, Yahoo, Outlook) automatically drop traffic from mail server IPs missing valid forward-confirmed reverse DNS (FCrDNS) records matching their HELO banner.
About this tool
How to use it
- Enter an IPv4 or IPv6 address into the lookup input or choose one of the sample IP preset chips.
- Click 'Check IP Reputation' to evaluate abuse confidence score, network type, and DNSBL status.
- Review the Real-Time Blacklist (RBL/DNSBL) audit matrix covering Spamhaus, Barracuda, SpamCop, and SORBS.
- Inspect threat category tags indicating SSH brute force, spam bot relaying, DDoS reflection, or proxy exits.
- Generate an RFC-compliant Abuse Contact Notification template to forward to the host network's NOC.
Why it matters
Security engineers and sysadmins investigating server intrusion attempts, email delivery rejections, or malicious scraping need an immediate, trustworthy blacklist check without signing up for expensive enterprise threat intelligence subscriptions or getting capped by strict API rate limits.
When to use it
Use during server security audits, when diagnosing email bounce-backs caused by IP blocklisting, when investigating suspicious access logs, or before routing production traffic through new hosting providers.
Common questions
What is a DNSBL (DNS-based Blackhole List)?
A DNSBL is an automated database published via DNS that catalogs IP addresses known for originating email spam, malicious bot activity, malware command-and-control, or unauthorized network port scans.
Why is my IP listed if I never sent spam?
Residential IP addresses dynamically assigned by consumer ISPs are frequently placed on policy blocklists (like Spamhaus PBL or SORBS DUL) because legitimate mail servers should not originate from home residential lines. Shared VPS providers can also inherit bad reputations from past tenants.
How can I request delisting from an RBL?
Visit the official removal portal of the listing organization (e.g. spamhaus.org/lookup or spamcop.net/bl.shtml), resolve the root vulnerability (e.g. compromised CMS script, open SMTP relay, or malware infection), and submit an automated delist request.
What is a Bogon IP address?
A Bogon is an IP address that should not exist on the public Internet, including RFC 1918 private subnets (10.0.0.0/8, 192.168.0.0/16, 172.16.0.0/12), loopback (127.0.0.1), and unallocated IANA address blocks.
Is my query logged or shared with third parties?
No. The lookup tool executes purely within your client browser session with zero remote telemetry, cookies, or query logging.